The People's Perspective on Medicine



Keflex (generic name: cephalexin) belongs to a class of potent antibiotics called cephalosporins. It is one of the first of these to become available generically and is now often prescribed as cephalexin.

This drug works against a wide variety of germs, including those that cause infections of the skin, lungs, throat, prostate, urinary tract, bones, and ears.

Cephalosporins are broad spectrum medicines that were originally discovered in one of the world’s most unlikely locations.

A fungus found close to a sewer outlet along the coast of Sardinia turned out to cure a number of nasty infections. From this chance observation many extraordinary antibiotics have been developed.

Side Effects and Interactions of Cephalexin (Keflex)

Side effects from cephalosporin-type antibiotics are generally mild. Nevertheless, it can cause a range of digestive tract disorders.

Indigestion, stomach pain, nausea, vomiting and diarrhea have been reported. If diarrhea becomes severe contact your physician, as it may be a warning of drug-induced colitis.

Other infrequent reactions to be aware of include rash, itching, vaginitis, headache, confusion, joint pain, fatigue and dizziness.

Cephalexin may affect laboratory test results. Liver enzymes may become elevated and false-positive results may show up during certain diabetes tests. Make sure that the laboratory personnel are aware you are taking cephalexin if you have blood drawn.

And remember to report any symptoms or suspected side effects of cephalexin to your physician promptly.

Special Precautions

If you are allergic to penicillin-type antibiotics, alert your physician immediately. Some people who are sensitive to penicillin may also react to cephalexin.

Symptoms such as breathing difficulty, wheezing, sneezing, hives, itching, and skin rash require immediate emergency treatment.

Life-threatening anaphylactic shock may produce an inability to breathe and cardiovascular collapse and can occur within minutes of exposure.

People with kidney problems should receive cephalexin only under careful medical supervision as the dosage will most likely have to be modified to prevent toxicity.

Taking the Medicine

Although this antibiotic is absorbed more efficiently when it is taken on an empty stomach, the pills can be swallowed with food, especially if they upset your stomach.

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About the Author
Joe Graedon is a pharmacologist who has dedicated his career to making drug information understandable to consumers. His best-selling book, The People’s Pharmacy, was published in 1976 and led to a syndicated newspaper column, syndicated public radio show and web site. In 2006, Long Island University awarded him an honorary doctorate as “one of the country's leading drug experts for the consumer.” .
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Have had Keflex before without any problem but Alprim didn’t work for Cystitis so am on
Keflex again. Talk about nauseous so off to have dry biscuits and yet more water. Told it’s more common as one gets older. That’s all I need now. Will be back if the Keflex works.

I started Cephlexin yesterday for a dental infection, 500 ml 3x a day. Diarrhea, nausea, migraine headache and joint pain within 10 hours. I am allergic to Penicillin and after reading just some of the warning out on the internet about this drug…disturbed it was prescribed to me in the first place. What does it actually help and do that even justifies its use!!!

I was prescribed cephalexin for a uti. Within 24 hours I had severe stomach pain and had to stop taking it. After four days of pain a blood test indicated pancreatitis and I was admitted to hospital. A CT scan ruled this out and I have been diagnosed with a stomach ulcer. Never had one before, now been nearly three weeks and I’m still in pain, still taking narcotic pain relief, still having treatment and, incidentally, still itching all over my stomach.
To add insult to injury the uti was discovered during a routine checkup. Had no idea…

I finished this RX after taking it for 10 days for a UTI. I’m still having extreme tiredness and bloating with stomach pain. I don’t know why it’s taking so long to leave my body but I don’t ever want to take it again. I looked at the other meds for a UTI, and I can’t take any of them due to earlier side effects. I just hope I don’t get another UTI!!!

I refuse to take Cephalexin, as side effects horrendously unpleasant. Must be another drug out there for infected oedema in one leg only.

I just posted, today, November 30, 2017. I forgot to ask- has anyone been given Keflex for a uti/kidney infection. I’m interested to know side effects and what and where the pain was regarding the kidney nfectiom. How much were you on and for how long. Outside of testing urine culture did anyone have to go for any tests, MRI, CAT SCAN?

Into fifth day of this antibiotic for UTI and have pain in my sinuses and headache as well
as sneezing and sneezing. Have just 2 more days to continue, should I do so. I was ok for the
first three days. I am on Warfarin, Bisoprolol and Amlodipine as well and have AF


Woke up 4AM on November 30- today, with burning during urination. I knew it was a UTI. A couple of days before that my kidney, right side, was bothering me. Then the UTI appeared. This is my first day, and I feel extreme nausea. My right side kidney, not so bad. Today is Thursday. I have 500mg twice a day. If by Saturday not feeling better will go to see my doctor. I’ve taken different antibiotics for sinus, bronchial – never had side effects of nausea just a muscle weakness- tired. Never took Keflex before.

Dear PP I am so grateful for the comments on cephalexin as I have a bottle of 500 mg pills prescribed for possible infection of of ankle sore from marine larvae in hotel pool I read the warnings on the papers and got fearful to take it God bless you all for speaking out I am using emu oil from Songline in Maine on my sore it is healing from the inside Thanks from Mary inTennessee

Does anyone who’s taken Cephalexin know how long the side effects generally last? I started taking Cephalexin a few days ago after the urgent care doctor prescribed them to me for an infection. I’ve been having a lot of nausea from the drug, but I know it’s not good to stop taking an antibiotic before finishing the full prescribed amount. Will the side effects last for the entire period of my taking them? Or will they eventually die off? I just want to know whether or not I need to go get some more phenagren in order to make it through this!

Having used Ibelix (Cephalexin) in the past, I was none too concerned when it was prescribed for multiple dental abscesses and a sinus infection. (Dosage: One 500mg capsule, three times daily.) While the initial side effects were tolerable (nausea, headache, jitteriness, sweats, changes to vision), the second and third courses were horrendous. Symptoms increased to include migraine, joint pain, mouth ulcers, peeling and swollen lips, facial swelling and numbness (which was advantageous for stopping the severe dental pain), difficulty swallowing, throat swelling, asthma and wheezing.

Funnily enough, my general practitioner advised me to continue taking the course (s). However when I stated passing massive blood clots, I declined further treatment.

While I knew for a fact that the afore-mentioned symptoms were related to Cephalexin exposure, convincing my medical practitioners (including a so-called allergy consultant) was another matter, as they refused to accept the association (even when the literature from the drug company themselves mentions the association!) I was however personally able to verify the link because I had kept detailed notes (and photographs) during the treatment period. I had also taken the liberty of trialing the removal and reinstatement of the drug. Eg. Each time the drug was removed, my symptoms disappeared within several hours. Likewise, each time the respective drug was reintroduced, the symptoms returned within a short timeframe.

I have since discovered that (despite being a rarity) internal bleeding, numbness and swelling are indeed associated with Cephalexin usage. After perusing other comments within this section, I found I was not the only one to have discovered this link (TKS on February 3rd, 2014, Gina on December 12th, 2012, Tami on October 4th, 2011.)

I recently discovered this drug is contraindicated for use with patients with heart conditions and Mastocytosis due to the risk of cardiovascular collapse. It has been my experience (and that of many others) that many doctors ignore obvious ‘allergic’ reactions in favour of continued treatment, despite the horrendous effect on patients. (Informed consent is vital!)

While probiotics (containing ‘live’ bacteria) may alleviate gut symptoms, we need to learn to listen to our bodies and keep in mind that ALL allopathic drugs have side effects. At the end of the day, the drug in question did nothing to resolve any of the bacterial infections my body was plagued with and went on to cause oral and vaginal thrush. Incidentally, the facial numbness lasted for in-excess of four months, after discontinuing treatment.

Given the serious nature surrounding potential side effects, I personally don’t believe this drug ought to be dispensed for minor ailments, particularly those that can be dealt with topically, as there are many more (less harmful) treatment options available. For those suffering from recurrent urinary tract infections (UTI), there are better solutions. Eg. D-Mannose, vaginal wiping (after toileting) with a mixture of Apple Cider Vinegar (Bragg’s Organic Raw Unfiltered), Bi-carb soda and water) and other dietary/lifestyle changes.

Remember, at the end of the day, NO-ONE has a vested interest in our health (and survival) other than ourselves. Thus, our relationship with our medical practitioner (s) needs to be a ‘joint’ partnership and not one of subservience.

Giant hives like spider bites 45 minutes after taking Cephalexin for bacterial infection from athletes foot. Palms itching. Sprayed the lesions with Benadryl. I am done. If podiatrist can’t cure it with amoxicillin, the one antibiotic I know I can tolerate, then I am at a loss what to do. Not taking more of this, that is for sure. For all I know I am allergic to the hideous orange dye in these capsules. Mad chemists at work?

A week ago I had bladder surgery and afterwards was placed on 500mg Cephalexin every 8 hours. A couple of days ago I noticed a rash on my arm. I took a Benadryl and the rash was gone that evening. Tonight my back felt itchy and after looking in a mirror, a rash was all over my back. I took another Benadryl and will be calling my doctor in the morning about this.

I’m having to take 500 mg. of keflex 4 times a day and 500 mg of ceepro 2 times a day. How much probiotics should I be taking to help put good bacteria back into my system?

I got Cellulitis in my leg from a spider bite and was given Cephalexin. After completing the 10 day supply, I kept telling my boyfriend I still wasn’t feeling good, dizziness, nausea (but no vomiting), fatigue, headaches, itching and rash. Yeah me, now a reaction to the Cephalexin. However, at the same time I got the spider bite diagnosis, I also was diagnosed with s severe case of poison ivy and was given prednisone to help with that, so I can’t have that again so soon… my question is, how long do these effects last? I am so tired of itching!!!

My daughter was taking Cephalexin for an infection on her ankle. She had a sore that she picked at until it became infected and turned into cellulitis and possibly MRSA. Anyway, she was given two antibiotics, one of which was cephalexin. She finished one of them, but still had two more days worth of Cephalexin left when she developed a red itchy rash all over body and swollen lips. It started on her arms and chest, and looked like a sunburn, but then quickly worsened and spread all over her entire body. Plus her lips are swollen.

No fever, no nausea, no vomiting, no body aches, but she does have a head ache and is super tired and irritable, or maybe that is just her. Anyway, my concern is whether or not this will develop into something more serious, or will it just go away eventually since I have taken her off the Cephalexin. I don’t want to take her into the doctor just to be told to take her off the cephalexin and keep an eye on her. I gave her benadryl which didn’t seem to make a difference.

Any advice? My daughter is 15 by the way. Also, if she is allergic to the Keflex family, will she be allergic to other types of antibiotics?

I’m a 21 year old male, and was prescribed 500mg of Cephalexin twice a day for Pharyngitis which is very similar to strep-throat, but with more severe swelling. Anyways, it helped the swelling go down but I felt very nauseous and dizzy in general on Cephalexin. The next day, I also had very bad stomach pains – as if there were a bubble in my lower abdomen. Suddenly, I was waking up every morning around 4am or 5am with severe stomach aches and felt like vomiting. The discomfort in my stomach is still there several days AFTER I stopped taking the medication and I’m still feeling pretty light-headed even now.

I seriously regret taking this antibiotic and will be visiting a doctor again soon to find out if these side effects are. I recommend avoiding this medication at all costs – as for me, it’s a world of pain.

I’m one of those people who are allergic to most antibiotics.

Hi rob,
Im going through the same ordeal.. ive stopped taking the meds, its only been 1 day so far.. i hate these things. My question is how many days post abx were you lightheaded for? Cuz i cant deal

Your Doctors should’ve all told you that after you take the course of antibiotics for the infection you have that you should replenish your system with good PROBIOTICS. I am on Keflex right now for a UTI however the ER doctor agreed with me on taking the probiotics I had already ordered after seeing the urgent care doctor about not feeling well.

I had been given Cymbalta years back and that messed up my digestive track. Taking probiotics has helped immensely with that. I also was not absorbing all the vitamins I tried to take daily. I found a patch for that now. So far so good. Ask your doctors about taking probiotics after completing antibiotics. And ask about a multivitamin patch.

I took keflex recently and have had pink (bloody) vaginal discharge for 5 days. It started a few days after I stopped taking the keflex.

I had this too! 3 days after. It was very scary and concerning. This medication is now on my “do not take” list.

I too have been taking Cephalexin for 5 days now and I too am experiencing problems with the vaginal area it’s very uncomfortable does this mean I’m allergic and how do I seek relief? And also my left side is still in pain does that mean the meds aren’t working??

You probably have a yeast infection and should take Monistat or something. The one day treatment or 3 day treatments don’t really work. Monistat does burn when you take it so if you get that make sure to get the kind that has the cream which helps to stop the burning. Or you can get a pill from your doctor that takes the yeast infection away. I think the pill’s name starts with a D but I can’t remember. Good luck.

I was on keflex 4 days ago, and I have experienced nausea, constipation and overall fatigue. I am glad I checked this site cause I have been feeling so bad and could not explain why. At least now I know what was causing all these symptoms… I will definitely up my water intake to get rid of any left over drug from my system.

I was placed on an IV of Rocephin for 7 days with a combination of Bactrim for an infected bursitis on my elbow. I was switched from Rocephin to Keflex after 7 days due to a change of doctor. I was also prescribed Tamiflu b/c I was showing flu like symptoms. I was kept on the Bactrim even though it was giving me continuos diarrhea. After the first day on Keflex (4 doses in 24 hrs) I woke up with hives and a high fever. I immediately stopped the Keflex and Tamiflu and took Tagamet and Benadryl. The hives spread down my torso onto my arms and legs, the fever and body pain continued into a burning aching. I was hospitalized 2 days later for extreme dehydration and hyponatremia.

After 2 days of getting fluid drip, morphine and oxycodone in the hospital I was released. I immediately began suffering body and joint aches and pains to the point I could barely walk as well as constipation. I was the prescribed prednisone which only seemed to help very little after 7 days of being on it. Since I have stopped prednisone as well as all other antibiotics I have continues joint and body aches as well as an all over body itching that has no rash or sign of discoloration. My primary care physician as well as my rheumatologist have applied the wait and see method, but I am starting to go insane with the pain and itching.

Has anyone experienced those symptoms after being on any of those medications and for how long after you stopped taking them?

Constipation and joint/body aches are likely from the morphine and oxycodone drip and/or drip “withdrawal.” They could likely take a while to go away, and there’s really nothing you can do. I’d try to not take anything for a while.

I to suffered from joint pain and really bad itching after taking cephalexin, and the sad thing about it all is that I stopped taking the medicine in January and it is now April and I’m still experiencing these bad pains and itching. And I was never bothered with joint pain or itching prior to taking it. I go see my Rheumatologist for the first time tomorrow because my husband finally told me enough is enough and I need to be checked out because it’s really bad.

I started taking the generic version of this about 24 hours ago and have now thrown up twice and feel nauseous and tired. I was given this for an infection in my tooth and have taken it before and never had any issues. I called my dentist and was told nausea and vomiting are not a side effect and to continue to take this medicine.

My husband was just told he has strep throat today and was given cephalexin to treat it. We arrived home at noon today he took one w/ lunch. He has had a severe headache and raging fever and nausea all afternoon. The Dr. suggested to take three today, so he took another one w/ some soup at 5. He feels worse now then he has this past week, and he has been feeling really bad. I read the side effects and all his symptoms were right there. I am not giving him another cephalexin and will be calling the Dr. for something different tomorrow. I guess research is the best advice after 5 when the Dr. is gone for the day and Thank Goodness for sites like these to inform everyone. I hope more people will stop taking this antibiotic at the first sign of side effects. They are listed for a reason, if you experience them even one, stop taking the drug, it is just not worth the suffering in my opinion.

I hope this helps someone else out there trying to decide what in the world in happening to them all because they took an antibiotic.

If you experience any side affects stop taking it immediately – what brilliant advice. I know I sure as hell would prefer to have an infection transition to the blood stream and cause sepsis than deal with muscle soreness, body aches or skin rash. Advice like that will get people killed, you might want to consider that.

I’ve been taking multiple antibiotics for a week to deal with an open wound, caused by blunt force trauma, where roughly three square inches of skin was peeled off my shin (once stop close to 1/8″ deep) and resulted in the exposed tissue becoming infected and cellulitus forming in my ankle.

The ankle almost doubled in size making its use very difficult. In the six between the injury and seeking medical care my blood pressure had jumped approximately 40 percent and my white blood cell count was over 11,500.

I’ve experienced multiple side-effects from the various antibiotics which while miserable are far better than requiring IV anti-biotics to treat sepsis which frequently results in major organ damage, not sure about you but I’d rather suffer though some discomfort and still have functional kidneys.

As for Staci’s reference to her daughter developing cellulitus and possible MRSA. Please do some reading and learn what these things mean. ANY Staph infection has the possibility to be MRSA though it is unlikely that a non resistant strain of bacteria will undergo the mutation(s) which make it resistant to penacillin based anti-biotics in the short duration of your daughters treatment. That being said you do improve the chances of this occurring by stopping treatment before receiving an alternative.

Always ask a pharmacist they know more about the drugs then the doctor

I have been on this antibiotic for a UTI. Have not had any bad side effects. It seems to be working well for me. Eating yogurt everyday was recommended by pharmacist.

My medical doctor prescribed 500 mg 4 x a day for kidney infection for 14 days. I actually shocked at how sick and nausea, my stomach pain is unreal, all my organs were checked for inflammation just to be on the safe side, all looks fine. I called my naturopathic for second opinion to take a closer look and he said, antibiotics is what you have to take for kidney infection. I decided to take it but if I get any sicker I’m requesting an antibiotic IV because I’m don’t want to suffer anymore stomach pain. I have another plan in place if i cannot antibiotics that I know. Cures without all the side effects.

I took it only for seven days and passed out and was taken to the hospital near death.

This drug has made me psychotic as did norfloxacillin many years ago. Came down 2 months ago with such severe pain on top of my left hip that I couldn’t stand and was nearly passing out. Hospital put me on an anti-biotic and rehydrating drips. Tests on urine showed UTI and ultrasound showed absence of passing a kidney stone.

Was put on course of flufloxacillin. Doctor back home tested urine which still showed nitrates (sign of infection) and put me on a course of keflex. Have finished course 10 days ago and still got UTI and the symptoms mentioned in above comments (nightmares, feeling of impending doom, getting stuck in negative thought patterns, insomnia but no digestive problems) have not faded.

Have refused to take a take a fourth course of antibiotics so am going to exist on a diet of pure cranberry juice, steamed vegetables with live yoghurt and probiotic pills for 6 days then have my urine tested again. Have not slept for more than 14 days ago despite taking mild medication to help me. Friends say I look like death warmed up. How long will the side effects subside? I will tell you if my home grown treatment works.

I took this for my cyst everything was going smoothly. Until I got major headaches and the light bothered me. Then I would fall into a deep sleep and wake up with confusion feeling numb. So I went back to the doctor and she said I’m fine and to take Advil.

OKAY I did and then I got brain fog and woke up again not knowing where I was so my sisters rushed me to the hospital. 4 hours later my doctor tells me I’m fine and to finish pills 500 mg and to take 600 mg of ibuprofen :( finally I asked him about my symptoms, and he told me that the pill only causes diarrhea or stomach aches and I may be going to sleep with a migraine, actually, he said he doesn’t know. I told him I am not going to finish my medicine and I will find a new doctor. But the new doctor prescribed me Bactrim as well. Why oh why do they stick pills down clients throats – I’ll never understand.

It’s not the drugs its the doctors with ADD. Sent home from hospital with cloudy urine and negative bacteria. Urine progresses to a light cider mill apple juice cloudiness. In hospital (different one) UTI positive, injection of antibiotic, and sent home on keflex 500 four times a day.

Second doctor told me I was taking it wrong (500 every three hours) should take two five hundreds every twelve hours and just started. Have ileostomy (from UC). with chronic obstruction, Since keflex unbelievable weakness on top of my chronic fatigue, bloating, pain, aches, numbness of left face. MRI taken of head normal but have trigeminal “neuropathy” nor neurolga (means pain). I am told its possibly from either diabetes, infection, or tumor after MRI. Appointment with specialist soon,, Meanwhile mostly left side aches in shoulder, stoma area (hernias), knees, wrists, finger joints, abdominal pain around stoma incessant.

Second doctor wants me to continue and extend use of keflex as I am 69, I have stage 3 CKD and renal doc says it will not affect my kidney. I am miserable and feel I have a alien in my belly which is full of hernias, taking miralax, disgestive enzymes. Other conditions HBP. Osteoporosis, Sciatica, and spinal degeneration.

Though diabetic its under good control but I am peeing often (distended bladder). Temperature ranges from 97 to 99. Very achy and feel I have an infection. Urine now clear and yellow. Would like to hear from ileostmate who may have similar problems. I am hoping to have surgery soon to correct chronic pain from adhesions and partial obstruction of ileum though I am told this will be risky. Cannot take the cramps from blockage much more so I am willing to take the risk.

Keflex seems to have added gasoline to the fire but I am told UTIs can be very dangerous and can lead to kidney infections, failure as well as bone infections. Scared as I have a history of sepsis from UTI as well as ventral incision MRSA.

Started taking this drug pre-surgery and have continued. Can’t tolerate it enough to be able to finish it. The chest and abdomen pain is constant, burning and I feel so sick but can’t vomit. It’s really horrible. Also have a chest infection and the coughing brings the nausea up. Never, ever consuming this drug again.

I am also glad for finding this site. I’m having the same vaginal issues and it began the day before I had to take the last pill. Irritation is unbearable and swelling smh… How can I get comfort?

So I was prescribed this medicine when I had a infection in one of my testicles, after a couple of days later it went away, and everything is fine, then one day I woke up with a rash near my penis and I still have it.
I’ve put cream on it (mostly eczema cream and neosporin ) and yet when I wake up the next day, it’s still all flakey and rash like. Now after 6 days of being off the medicine, I wake up at 2, 3, 4 o’ clock in the morning feeling sick and feeling like I have to throw up, but never do. Couple this be depression? I’ve been a little depressed lately over a health issue. Could it be Allergies?
I’ve also been constipated, my poop has been coming out in balls. If this is all from the medicine, never taking it again.

Steroids are contraindicated when one has an infection!

Wish I had not waited so long to check this site. This is all very scary for me. Just had breast cancer day surgery last Tuesday and was given a prescription for CEPHALLEXIN; 500mg 3 times daily. Just 2 days left. I felt great after surgery (Lumpectomy plus 2 lymph nodes)except sore throat and congestion from surgery.
But these last few days my chest feels congested, I feel drained of energy. Despite feeling worse instead of better I continued to take the meds because I was afraid of pneumonia or infection of some kind. I am not taking any more. I am supposed to be walking 3 times a day but my heavy feeling chest, general all over achy painy feeling, and lack of energy is making it difficult. Of course the TERRIBLE POLLUTED AIR is no help either. My back has been getting very itchy now, too.
(And I thought since the pathology report said no cancer in lymph nodes or margins that everything was okay. But the radiology oncologist pointed out to me that I had INVASIVE DUCTILE CARCINOMA that is HORMONE DEPENDENT, that I had CANCER. The cancer had grown through the duct into the breast. He said he might be able to cut the treatments down to four but first I needed to see the medical oncologist to probably be put on a hormone blocker type med and for me to stop wearing my patch that I was only feeding the cancer! If I did that, I could possibly opt out of radiation treatments since I am 75.)

So, back in the day as a child I had an odd reaction to an old school cephalosporin where my stomach got really hard & painful & I was unable to eat because food would come right back up. As an adult I have taken Keflex a couple of times with no issues. This past Friday my PCP put me on Keflex for an infected cyst that is unable to be removed until the infection is gone. A short time after taking my 1st dose I developed an uncomfortable feeling behind my sternum, almost as if something was caught in my esophagus or like my esophagus was stuck in a muscle spasm. I have had this feeling ever since my 1st dose on Friday and it is only gone when I wake up in the morning but returns after my morning dose. The feeling goes away for a bit when I eat or if I take a deep breath and hold it for a while and slowly exhale. Some times the pressure is so bad it feels like I am going to gag or throw up. It seems like a rather odd reaction to a medication. Has anyone else experienced this with a cephalosporin? What are the odds it’s something totally unrelated to me taking this antibiotic?

I am currently taking Cephalexin (generic for Keflex) after surgery for nodule on thyroid. I too am experiencing the pain behind the sternum. If feels to me like a big bubble is sitting there. I feel like a big burp would help but it doesn’t. I have experienced this once before but I don’t remember if it coincided with taking antibiotics. I am also taking Prednisone for inflammation. I avoid medication and rarely have to be on antibiotics.

Thank God I found this site! I thought I was losing my mind when 2 days after stopping Keflex I began to experience vulva itching and swelling. I knew it wasn’t an STD as I’ve been married forever and had just had a normal pelvic exam only a few weeks ago.
At first I thought maybe it could have been a reaction from the Florastor probiotic I’m taking to prevent C Diff. But now I’m realizing from all the comments here that it’s the Keflex! I will never take this antibiotic again.
To help with the itch and a “dry” patch on the skin I began rubbing Manuka Honey 18+ on it. It’s a bit pricey, but I use that stuff for everything…it’s awesome. It’s been 3 days and it’s soooo much better, I can at least function now.

I have taken Keflex many times. It ALWAYS gives me thrush and a yeast infection. It usually but not always gives me diarrhea. I just take an Imodium with every dose. This time I was taking it for phlebitis. I got exhausted where I just didn’t want to move. Taking with probiotics helps.

I took this for cystitis but I had a terrible reaction to the tablets last night. I felt the same feeling just a little the night before but didn’t think much of it and contd the tablets yesterday.
Well, I paid for it. Muscle spasms, on a super high, body wouldn’t relax, diarrhoea, nausea (after taking every tablet), weakness, brain fog and no sleep til 4am for 20 mins when the reaction lessened a bit. Scary as and feeling awful today, to be expected, and I won’t be taking the last 3 tablets. I went with this brand because I had no reaction to it 8 years ago. I’ve had joint pain too, and stool problems (constipation) which ended up in diarrhoea last night – didn’t realise it could be from this.

Hello, I found this site after looking for a relationship between Keflex and herpes. I took Keflex and within three days had a huge cold sore break out on my mouth. This sore had been dormant for about 15 years! I was sure there was some cause and effect from the drug and now it seems accurate.

Been taking generic cephalexin for the past four days to prevent possible infection after having knee surgery. I noticed the last few days that I have been feeling light headed, dizzy and nauseous about a half hour or so after taking my meds. Today I decided to take each med independently. I started out first today with the cephalexin and sure enough about a half hour later I started to feel dizzy and nauseous. Additionally my back has been itching uncontrollably over the last couple days. I am fairly certain that it is the generic keflex (cephalexin). The other meds I have taken before without any side effects. Though I rarely take medications this is the first time I have ever had a noticeable negative reaction.

I have been off this drug for 7 days. I feel miserable. I have all the same side effects. Have you felt relief? If so, how long did it take?


I started a course of this drug on Mon @ one capsule x 4/day to address a possible infection at my breast. (Total consumed as of 2/21/14 = 14) By day 2, I noticed less burning and pain at said breast, as well as a decrease with swelling, HOWEVER, I began experiencing chest, shoulder and lower back pain (muscle versus joint or so I think) almost at once. My breathing has been shallow at times, to the point of having to sigh in order to get a full inhlation, although this has been intermittent.
My vagina has been tingling as if a yeast infection is about to begin. I have had a sore throat and a headache. I have also had typical intestinal issues (gas, bloating and increased stools). I called my PCP and spoke with him via a RN and PA… uh, yes. Anyway, he said I should stop taking the med at once and monitor my course over the weekend. All I know is that my body is out of sorts and that it feels quite foreign at this point. This drug and the quick fire presentation that has resulted in response to my taking it are a serious concern for me. This med is a definite no go as far as I am concerned. I am posting so that others might be helped.

I have been taking Cephalexin for a week now for a UTI and I am 42 years old I started having severe joint pain in my right arm and my period was very heavy with me passing clots like crazy and it doubled the time it normally last, I will never ever take this medication again an ER Dr. prescribed it.

I have taken Cephalexin and both times started coughing up blood. The Dr’s, pharmacist, TEVA the manufacturer all say it has NOTHING TO DO WITH THE MEDICATION.
I take the medication and within two days I’m coughing up bright red, fresh blood – as much as a quarter cup. I started this for a tooth problem so I wasn’t even coughing. I just sort of clear my throat and up comes all this blood.
What’s making me mad is to call the manufacturer and report this and they don’t care. They just say it’s not possible. Stop taking it – no more blood. Take it – more blood.
I see in the side effects, although not common, it says you can cough up blood so why do these Dr’s act like I’m crazy?
AND where is this blood coming from? Some has clots does this mean I could get a blood clot? I just wish dr’s would listen to you when you KNOW something is happening.

I’ve been taking the prescribed dosage of keflex 500mg 4 tablets per day…post open septoplasty (nose reconstruction) onto the second course now…as doc said I needed to take repeat…but I just feel incredibly fatigued .. Strange rash on my hand…and generally just blah….thinking that I’ve got to start taking a probiotic ASAP …. This is an effective antibiotic…but like all destroys the bacteria that’s bad…and also destroys all the good gut flora that we need to feel good and to protect our immune systems…flatulence is also something I’ve noticed…lol..

Developed a very severe widespread allergic blistering rash to Keflex within 36 hours of first dose. Doctor said to stop medication immediately.

I was prescribed a double course of Keflex (Ibilex) for a UTI as it was my third in a matter of months. On my second packet I started to get welts on my body and face, swollen followed by cracked lips and inflamed eyes with blood red lower lid margins.
Most notably I developed approximately 8-10 mouth ulcers of varying severity. One the size of a drink bottle lid! I couldn’t eat for a week, looked like some sort of demon and the welts were itchy but the doctor thought it may be a virus that I would recover from. Just in case she advised me to stop taking the Keflex. Symptoms disappeared within a week or so.
Recently I was diagnosed with my fourth UTI in a short period (microbes present in wee). Before I was able to get to the doctor I weed in a sterile container I had been given and self-treated with the leftover Keflex from the previous double course until I could get to the doctor. I took three tablets across two days. The next day I noticed two tiny mouth ulcers in my mouth and didn’t think much of it…
That evening I woke at 2am in a sweat and feeling extremely itchy all over my body but especially on my arms, chest and face. Looked in the mirror and I had full blown hives everywhere, swollen eyes and lips. I called the government healthcare line (Australia) and was advised to go to the Emergency Room immediately where I was given antihistamines and offered something else to ‘weaken my immune system’ as my body was attacking itself in an allergic reaction seemingly to the Keflex as it occurred both times I took this antibiotic.
This time was much more severe. I am at home now but have been advised to visit the hospital if I begin to flare up again.
In summary I am never taking Keflex again and have been advised to get immunology testing for other antibiotics I may be allergic to. I have never been allergic to anything in my life! Strange that it would start at 23 years.

I am also having horrible joint pain in my hips and lower back I can barley walk and have to use my cane! None of my pain medication will even ease this pain so I feel for you!

Hello, How long did these side affects last? I have similar symptoms 2 months after taking Cephalexin.

I took Cephalexin for a bug but which doctor determined was “cellulitis” bacteria under the skin. I took cephalexin,500mg 4 times a day for 7 days. The itching and swelling went away but then I broke out with an oral thrush. I was given nystatin for 7 days 4 tiems a day. After all these meds I havent felt the same. I started with nausea, headaches and stomach aches. I feared I had appendicitis but doctors said I was fine. I had blood work done and urine test. All test came back negative. I had an ultra sound done and that was normal. Still, almost 2 months later im having headaches all around my head and stomach aches and bowels arent the same and constipated. Its very annoying to hear im ok and that its not the meds that did this to me. I was fine until I had this bug bite and took all these meds. Anyone have a similar story?

Hi, I also went in to see a doctor for a bug bite I had on my stomache and it turned out to be “cellulitis” bacteria under the skin. The swelling and itching went down but now, Im having headaches and stomache aches. I developed an oral thrush due to the meds and was given nystatin mouth wash. Now almost 2 months later im dealing with headaches and stomache aches. Did you experience anything like this after taking cephalexin?

Hello, I too took Cephalexin and 1 month and 2 weeks later im still having headaches and stomach aches. Occasional pain in joints. How are you feeling now? Was taking cephalexin the reason why you had issues 5 weeks later??

I started taking cephalexin and about half an hour later I had extreme itching on my hands and arm. In which my labia also became swollen and itchy. Uggghhhh, I had taken this med before and it caused vaginitis. I will never take it again!!

Antibiotics are for treating bacterial infections not viruses. The rashes people are complaining about are most likely fungal infections, typically yeast overgrowth, due to the absence of good bacteria found on the skin that keep them in check. Monostat for girls and miconzole cream for guys.

Got it from a dermatologist for an infection under my skin in my upper arm 500 mg twice a day. (Cyst that will be removed after swelling goes down.) I just noticed that my stomach cramps, I have gas and I am itchy under my skin a lot and all over. No visible rashes, but I have a bad headache and sore throat and itchiness in my ears and sinus. The swelling is going down, and favorably, my toothache problem and urinary problems are feeling better.

hey any tips ?? I’ve been taking this antibiotics for 8 weeks due to re current uti, I suffer most side effects especially itching and a rash in my genital area as well as thrush I take my antibiotic with natural yogurt to try and ease this off but had no look I also have a thrush cream // any tips ?? I also suffer with duplex duel kidney and have back ache constantly .. any tips would be fantastic thanks

I was prescribed keflex 500mg 4 x a day for 10 days for a bacterial skin infection/acne. I just took one dose (500mg) and within 30 mins my right ear started itching and felt raw. I put some noesporin on it not thinking anything and then my left ear did the same thing. Now I am itching in spots all over my arms legs and stomach. It looks like a tiny raised bump in every spot that starts to itch and my skin is a little blotchy.

I been going through hell, burning itchy itchy skin. Red Rash all over my face had to go to work like this. This drug is a torment from hell.

I was put on Keflex for 7 days due to a tooth abscess and pre-op for a tooth extraction. After 2 days, I notices blisters on the instep of both feet and around my toes. Accompanying this was a red rash of the lower legs and feet. I continued on the medication for the full 7 days. I called a pharmacist for an explanation and she could give me none. I have been off the medication for 3 days now and still have the rash. I am treating it with Benadryl Gel and using triple antibiotic ointment on the blisters. I am 70 years old and have never had a reaction to any medication. What gives?

Same reactions for me! Sick as a dog. After the first four doses, I had intense nausea for about four hours. was very tired, vomiting, nausea, very sick indeed. I am off the cephalexin after taking seven doses (I reduced from four a day to two). Thought I would try one more this morning. I vomited within 1/2 hour. Then have been so sick to my stomach for about four hours now. Was taking it for a leg sore. It does look like it is healing but the side effects of this drug are too intense.
Going to only use the steroid cream and see how the healing goes. I agree that there are not enough side effect warnings for this drug from the pharmacy. Will never take again! It makes me feel nauseous just thinking about it.

Aloe Vera

I was put on Keflex for an infection in my finger. I was supposed to take 500 mg 4 times a day for a week . After about the fifth day I started to get itchy and my skin was irritated. By that I mean sore to the touch kind of like when you get the flu and you get shooting pains. It was like that but a lot more sore. I also started to experience joint pain, mild at first but it got worse. All through my legs my feet and toes. The bottom of my feet were sore. I also had some joint pain in my hips but that only lasted for about a day. Also my labia was very itchy and had bumps on it and was swollen. Of course I stopped taking the medication. My finger is fine however I’m having a lot of difficulties with pain in my joints and some itching. I cannot believe they can prescribe a medication like this. My infected finger wasn’t nearly as bad as all the stuff that started after I took keflex. It can’t be good if it causes all these bad side effect. Unbelievable. How long before this stuff is out of my system? Does anyone know?

Years ago unbeknowst to me I was given a generic medicine, for something I have always taken – I broke out in red spots – they found out the medicine had been made in Egypt – so I only go name brand on that one – I notice a statin I take had a company in Yugoslavia based – my sons friend who is a pharmacist said that as long as the main or action drugs are the same – they can use any kind of filler – – I wonder how many of these fillers are causing folks problems??

I have had to take cefilaxin for teeth a number of times in my life but this latest time I have been experiencing a fever like high, watery stools and slight dizziness along with a rapidly emerging mildly itchy rash. So far it’s not on the jewels though, thank JESUS. It is working great to reduce inflammation in a tooth that I desperately need to have pulled but I worry in case this sudden new allergic response should take a sudden turn for the worse.

I was put on Keflex for a sore eye lid. It cleared up but I got a horrible red bumpy rash all over my chest. Went back to the Dr. and she put me on Keflex again to clear up the rash, the rash looked very angry and ugly. Well, after a steroid cream and a hydrocortisone cream the rash started getting worse. After reading all of these comments it dawned on me it was the Keflex! Dr. didn’t figure it out.
I stopped the Keflex a couple of weeks ago and it has gone from about 1,000 red bumps to about 50. But, now today I look under my breasts and the rash has spread very nastily there. I am so tired of this and I will never take Keflex again. I just hope it clears up soon. It’s summer and I want to go swimming in our pool here where I live but I can’t expose the rash to the sun or the chlorine. What a horrible drug.

Did this go away for you? I finished medication last week but my stomach is still really bothering me and my stool has been odd colours and consistency.

I have been done this medication for over a week now. I was given it for bronchitis. A couple days before I was finished my prescription my stomach began to bother me and I would have bowel movements up to 6 times a day. Now my stomach feels upset or hurts throughout the day and my stole has been green. Has anyone experienced anything similar or should I go back to the doctor?

WOW… So here is my cephalexin story. I have Rosacea… really bad. It has traveled from one cheek over the nose and to the other cheek… but stays on my nose and wont go away. I have been on Doxycycline for minimum of 5 years.. YES 5 years… it’s like a 3 month bandaid for rosacea and it finally stopped working all together.
I went to the derm.. ofcourse.. same old questions, same old answers same old “prescribe antibiotics” but this time… Cephalexin. I have never ever had an allergic reaction to anything in my entire life which leads me to the nightmare.
I received my pills on a Friday before I was going away on vaca.. started them 500mg once a day. I had shaved all the privy parts as most women do prior to vaca and went about my day as usual.. about 2 days in… I was scratching and uncomfortable in the lady parts and chalked it up to shave bumps and irritation from scratching.. no pain no, no mess.. just itch…
2 weeks later and my vagina feels like its been kicked by a cowboy boot… felt like a really bad bruise… Still I think it has to do with hair growing back and me constantly at it with my nails scratching… so I put neosporin on it and I forget to take my meds for my rosacea for a few days ( because it wasn’t doing a darn thing for it) and all felt a bit better down south.
I start my meds again.. trying to be diligent and BAM.. it’s back and red, bumpy, inflamed and spreading, then it FINALLY FINALLY dawns on me… all this started the day I took Cephalexin!!
I’m so stupid. I also don’t go to doctors unless I’m on my deathbed. So here I am with this nasty rash… I am going to stop the meds and put virgin unrefined coconut oil on my rash and if it doesn’t get better in a day or two.. off to the doctor I go.. it’s been about a month now since this all started.. so I hope I’m not too far gone.
Also going to call Derm and tell her about the reaction. So I hope I helped the ladies out there who don’t want to talk about their privates… I don’t either… I’m just so relieved that I’m not alone…

I am 21 weeks pregnant with a kidney infection I’m on cephalexin which I started today I’m on 3 tablets a day but I’m now feeling like I’ve got indigestion should I be worried as I’m also an asthmatic I had a uti at 6 weeks pregnant and had no issues please help

Started taking Keflex 500mg 4 times a day on Tuesday for a secondary skin infection on my foot. Today is Friday and I have a horrible sore throat and bad diarrhea. My skin is itching on my chest and see little bumps that I didn’t have before. I feel really tired and mad at the world! I am going to stop taking this med right now!
Peoples Pharmacy response: Be sure to check in with your physician to let him or her know about the rash the diarrhea and the sore throat. You may need a different antibiotic you manage your infection.

I tried this once for seborheic dermatitis.
No problems. Tried it again for same reason and all hell broke loose! dizzy, exhausted, devere muscle weakness. I guess this cephelexin has a memory, it will allow one time use to suck you in and then lowers the boom!

I recently was prescribed Cephalexin 500mg/ 4 times a day for a UTI and kidney infection. The first 4 days had the worst stomach pains. Now I have developed the worst yeast infection and swollen labia as well. Anybody else experiencing a horrible yeast infection?

I am using this drug for abscess on toe. I have had a lot of the sweating, sleeping a lot, stomach issues and dizzy in the morning for about an hour or two. I also itch, but no rash and I don’t have a penis, so I’m safe there.

Your rashes may be yeast infections. Yes men can get them too. Get some over the counter anti fungal cream. It will clear it up in a couple of days.

I’ve been on cephalexin for four days for a skin infection. 500mgs four times a day for one week. So far my digestion is a mess. I’ve experienced constipation all four days without any diarrhea. Other strange things I’ve noticed? My skin is extremely dry, even in the areas not around the infection, chapped lips included. Lastly, I find its keeping me up at night. Every night. The skin infection though, responded right away and seems to be fading quickly.

OK so I have had my full course cephalexin 500mg 2 a day for 10 days. Only side effects were diarrhea (awesome) but none other of the above mentioned reactions. I did develop thrush 1 day after completing course but I suspect this was due to me being on antibiotics for 17 days. My throat however (which is why I have been on antibiotics) is no better. Back to the doctors I go (This time I will be asking for a referral).

Wow. I really need to stop googling stuff! (It ends up scaring the shit out of me) lol
I’ve had red tonsil beds and 1 swollen tonsil for about 3 weeks. 2 weeks ago I started a course of phenoxymethlpenicilin 500mg 4 tablets a day for 6 days. I finished them 2 days ago. Today I went back to the doctors as tonsil area is still red and 1 is still swollen(no improvement).
He has now prescribed me cephalexin 500mg 2 a day for 10 days. On the phenoxymethlpenicilin I had a bit of diarrhea (yay) but no other symptoms. After reading all the comments above I wonder what will I experience with cephalexin. I don’t remember having side effects from any antibiotics in the past (except diarrhea) so hoping I will be one of the lucky ones. I HAVE GUESTS FROM OVERSEAS STAYING WITH ME NEXT WEEK! I can see it now- rash, diarrhea etc lol.
I will let you know how I go good or bad. To the people reading this and starting cephalexin for the first time, if I don’t experience bad side effects there is a chance you wont as well, so don’t freak out!

I’ve taken it before with no problems. This time I got a sore throat and funny feeling eyes the third day followed the feeling very out of it and tired. I would also get a sunburn like rash on my stomach and chest that was accompanied by feeling very hot, even though my temp was fine. Told the Dr. They said to keep taking it unless I begin swelling or have trouble breathing….. so I did. On the fifth day I took it and experience the same thing only worse and my voice was a bit hoarse and had a little cough. Took some benedryl and everything went away, came back about 5 hours later, but not as bad.
I’ve decided to stop. I’m being treated for a uti and am 19 weeks pregnant. The baby was also very still while I was on it. Now I’m slamming cranberry juice and go back to the Dr soon.

Wow. I’m down here in New Zealand. 3 weeks ago I got a bite on my thigh from a flea or mosquito or something. Roll on 3 weeks and it was a bolistic out of control skin infection on my thigh that had gone from the size of a pin head up to the size of a hundred dollar bill. So off to the docs and as most antibiotics don’t do me any good as it is, I pleaded with her if there was any way I could avoid antibiotics. That was a resounding no and I got put on the world famous cephalexin at 500 mgs 4 times a day. Wow. I have just read all 113 comments above and I am absolutely blown away. I obviously have your standard issue joyful diahorreah, I have not ( praise the Lord ) had vomiting, I have the leg which has the bite getting better, (albeit very slowly) but it has swollen up to the size of an elephants leg, I have my poor wee labias just about shredded from scratching them to death, I have a rash under my right armpit itching like mad, a rash under my right breast, and general out of control itching rash here n there. I’ve had vomiting and diahorreah before from other antibiotics but never this insane intense itching rash.
I’m on day 4 and a bit and although it goes against the protocol of stopping antibiotics mid cycle I’m very very seriously thinking of stopping them right now. I’ve had several episodes of suddenly feeling out of it and like I was gonna drop on the spot, and today I have a feeling deep/low / inside/ back / funny feeling. Kidneys???. no stds, me n ma man 20 years strong n all goods on dat side. I too like all of the above will NOT take this again. hope this all helps. bless all you guys n gals xxxxxxx

The joint pain (the pain & stiffness would wake me up) from Cephalexin (500mg) was horrendous. It had gotten so bad that I considered getting tested for bone cancer (yeah, it is funny now!). I did not realize it was the antibiotics until two days after I had stopped them and noticed my pain had completely disappeared. I also developed hives for the first time in my life. I am allergic to penicillin like some others who had posted and also experienced severe joint pain. I will have to be stranded on an island w/a life threatening infection, to even consider taking this antibiotic again!

I started Keflex for a possible abscess tooth, had 2 removed and will have the possible abscess one removed in 2 weeks. He prescribed 500mg, 4 times a day, which is the highest I have ever taken of this drug. I have done fine with it in the past at lower doses like the 250mg, and I have to take this one as I am allergic to many other antibiotics. After taking this amount of 500mg 4xday,for a day and a half, I had itching and rash on stomach mainly and arms, back. Looks like sunburn, Also started getting severe sore throat and itching down below.
Called doc he said stop taking it, that I will be fine. This all happened today, so I didn’t take this morning dose, this would have been almost the 3rd day. If you have rash and itching from this drug, stop taking it AFTER doc says is ok, call doc when you can!! I asked if I could just decrease the med, he said no just stop all together!

I misread the dosage from the instructions, and took three 500 mg tablets at once to make up a missed pill from the am ( I am to take two pills twice a day vs. a pill twice a day). A few minutes later my fingers turned whited and numb, as if all circulation to them shut down. This did not happen when I took two tablets. I also felt extremely sleepy after just taking the one pill in the am. Just sharing so that others note that this can happen, as I read at least one other person had this happen. Just started the prescription. Hope not to have the rash issues!

I’ve been taking keflex since the 7th of Jan my tongue has a burning stinging tingling feelin its burns etc when I eat drink or smoke a cigarettes and when I’m just sittin down watchin tv. I’m allergic to penicillin so could this medicine be causin an allergic reaction? please somebody help me understand this pain and medication

Here’s one I don’t see here so far. I’m 46 (I think), sometimes I forget. Anyway, maybe I’m 47 don’t feel like doing math right now. I’m going through the female stage where I have periods like once every 4 months. It’s not regular enough to say, every any amount of time. They are very irregular but I seem to be going longer and longer without them, which is ahh kind of nice.
So yesterday I had a mole removed on my face and the doctor gave me Keflex. Today I suddenly started passing huge clots like crazy. It seems to be slowing down, although I still feel crampy. Could Keflex cause this? Or is it an unrelated event?

I, like Cherie, have had very few side-effects with Cephalexin…gas, which is a little embarrassing, and some dizziness at the start. Even now I am not sure these were all due to the antibiotic, as I am on 6 other prescription meds. If you haven’t taken it, don’t be scared off of trying it by others’ reactions, just watch your own reactions. And for Heaven’s sake, if you get a rash or breathing difficulty, STOP TAKING IT AND GO TO THE EMERGENCY ROOM!

I was prescribed Cephalexin for an ear infection that had been turning bad. After a few days, I started getting itchier and itchier and they would very easily turn into rashes. My foot also started to swell! It was terrible and I went back to my doctor and she claims I have eczema. But the weird thing is, I’ve never had any rashes like these or itch cravings like these before I took this prescription. I’m thinking I do have eczema except that its been dormant for the most part and that Cephalexin made it flare up. Now I’m stuck with ugly rashes all over my body and a crave to itch every moment I’m awake.

I have been taking oral cephalexin now since August 16, 2012 and I still have another 3 weeks to go… my dosages 500 mg 2 caplets 3 times daily, so total 6 caplets per day. Earlier this year, I had a rare fungal infection in my lung… part of my right lung had to be removed. At the time of the surgery, the cultures taken from the drainage showed that I had staph infection also (in my lung cavity). I was sent home not with cephalexin, but a different antibiotics, along with my fungal infection antibiotic (that I will have to take for at least 18 months).
During that time at home, the chest tube site did not heal and I developed another staph infection and needless to say, I was really ill over the 4th of July holiday this year. Spent nearly a month in the hospital and for 6 weeks I was on IV infusion antibiotics, even when I was released from the hospital and sent home. After the 6 weeks, I was put on the cephalexin. Taking this antibiotic, I haven’t really experienced any bad side effects… just aching joints. This antibiotics has its good and bad side… we all experience it differently. I for one would recommend this to others.

Wow, After reading all this, I count myself lucky. I am going to add to it, however, since it helped me knowing that other people were experiencing similar side-effects. This medication did not come with specific enough instructions on dosage or details on what the possible side-effects could be, which is just irresponsible and very worrying for the patient. What’s worse is that my doctor had no idea this medication could cause a massive rash.
One Google search later and yes, apparently it does.
I was prescribed this antibiotic for cellulitis and while it did the trick, I broke out in a rash AFTER coming off it and off anti-histamenes. The rash was like hives, very red and itchy and it spread FAST. Resuming the anti-histamenes works to calm it down but a heads-up would have been nicer and made me worry less. I have also experienced the swelling in the joints, headache and fatigue.
Use with caution and be aware of what COULD happen. Your doctor may not even know/tell you…

I was given this anti-biotic for a lump that was growing on the back left/side of the bottom of my neck. Doctor thought that maybe it was an abscess that had begun growing due to maybe an ingrown hair. I had taken 4 of the pills when all of a sudden I started experiencing unbelievably bad pains in my stomach.
At first I thought it was gas and took Gas-X and alka selzer, which were of no relief. The pain was so bad it was like my inside organs in my stomach area were all swollen and sore to the touch. I have stopped the medication and will call my Doctor on Monday.
It has been over 24 hours and the pain has subsided somewhat but still very sore inside and when I cough I can feel the pain there still, very strange and very scary. I will not take this medication again, hopefully this will go away within the next few hours. Has anyone else felt this pain the their stomach, no diareha, no rashes as all the other post have indicated, just the pains in the stomach.

I was just checking to see if it was better to take on an empty or full stomach. Goodness! I am taking Cephalexin 500 MG 4x a day (today is the 5th day) because I had some gum disease issues and went for a deep cleaning. I do have diarrhea, but I’m just riding it out because the pharmacist said that anything I took would interfere with the effects on the infection.
I also have a bit of a headache, but I took some CVS substitute for Excedrin Migraine and put some tiger balm on my temples and it feels better. I would certainly say I don’t feel 100% and I’m getting my work done slower and my family has to make their own meals, but nothing terrible is happening. I am allergic to Penicillin, so the pharmacist said to have an antihistamine ready in case I had a reaction. No reaction. I’m sorry all of these people are having such a terrible time, but I thought someone who isn’t should at least leave a comment.

For everyone complaining of the side effects of this antibiotic all I have to say is that a lot of your complaints are common complaints. But not all people experience the same. I for one favor this antibiotic because it is a wonderful broad spectrum antibiotic. When people have complaints of common side effects most doctors don’t do anything other than treat symptoms of those complaints.
I’m sure that most of you know the idea behind beauty. “Beauty is painful”. In a lot of times that statement is very true but, we do it anyways. Treating medical issues can at times be the same. Doctors don’t get to excited about common side effects, that’s the patients job. As a patient it is your responsibility to let your doctor know what is going on and if you can handle it.
There are so many different drugs out there that you can try, mind you, they ALL have common side effects. No matter what the problem is, there is a medication to help with managing it but, you may have to deal with some unwanted and not so fun side effects. Bottom line…. neither you or your doctor know what kind of reaction, if any, you will have until you try it. You can’t get mad at the doctor just because you had a side effect. You must always always always be proactive in your own health care and take responsibility for it. No on can do it but you. And remember, you are the one that called the doctor in the first place.

I would like to thank everyone for telling about this medicine. I was told to take this medicine by my doctor but after reading the post by everyone, I do not think that I will. I pray that everyone gets better and has a full recovery.
PEOPLE’S PHARMACY RESPONSE: Please keep in mind that failing to treat an infection because you are worried about possible side effects could also have serious consequences. Discuss this with your physician before finalizing your decision.

WJ… how long did it take for your dizziness to subside?? I am on day four and the first symptom (dizziness) has appeared. I am stopping the drug today until I can speak to my doctor…thanks

My husband recently had surgery on his scalp and was put on cephalexin 500mg twice a day. Since using the medicine he has been unable to ejaculate. I am thinking it’s because of the medication. If anyone has had a similar effect happen please let me know. Any advice would be great! Thanks!

To Cal … PLEASE get your kidneys checked. Keflex has a side effect of something related to the kidneys (I forget exactly), plus the drug is filtered by the kidneys making them work harder. Your symptoms sound so familiar. I’m glad you are seeing the DR to ask to be taken off the medication. Hope it all works out.

My doctor has been treating me for sinusitis for over six months now and this is the third prescription for cephalexin. After taking this med 500 mg for 60 days I have severe pain in my low back every morning. Sometimes it wakes me up at around 2 AM. Now the pain has spread into my side making it feel like my ribs are caving in on the right side and I find it difficult to breathe. He also has me taking diabetes tussin and mucinex D. I think all these drugs are working against each other causing my pain. I have an appointment with him and am going to ask that I be taken off the medication. And go to Arizona and stay on the desert for a while to dry out.

Just finished taking Cephalexin as prescribed for 14 days for a mastitis in one of my breasts. I hated the pills which smelled like cat urine/litter box fumes. After 3 days of the medication I began having kidney aches with shooting pains in the lower and middle back on both sides. Also my fingers feel like they have arthritis this week.
Drinking more water to help the body move the drug out of my system helps the kidneys somewhat. Diarrhea on and off for 10 days. Now at the end of the 14 days I have very swollen and itchy labia minora, with no discharge and it doesn’t seem like a yeast infection, so nothing I can do but wait it out. This drug has been a scourge. Never taking it again if I can help it.
The only side effect mentioned in the pharmacy printout that matched my problems is the diarrhea. I am grateful to others for sharing their symptoms here, so I can see I am not the only person dissatisfied with the medication. I have not had an antibiotic for 8 years while pregnant and nursing my children. Used the most gentle non-chemical treatments for all those years. Now my children are all weaned so thought I would take a prescription for the breast infection, and I am wishing I had been prescribed something else instead of Keflex.

I think I am one of the *fortunate* ones taking this. Only taken it for a day, and no side effects, at least yet.

This is by far the worst antibiotic I have ever taken – ironically urged on me by a kindly pharmacist who assured me it would be better for a UTI than what I usually take.
I had to stop after 4 days of a 5 day course as the dizziness was unreal. I also had slight difficulty breathing at night. Upon stopping the medication I began to have digestive problems, only to find out that a close friend who had taken it for a week was vomiting blood before she stopped it.
Definitely not a drug I would use again!

2 days on 500 mg of cephalexin 3 times a day. Walking pneumonia diagnosis aches really bad! Sweating like crazy! Cold chills. Don’t know whats what now after reading this site. The pills or the sickness?
I may just stop taking it all together and go back to my amoxicillin 875mg pills.

Prescribed cephalexin for a finger infection (origin unknown) and been taking 500 mg 3x a day for five days now. I have no side effects at all except have been feeling extreme fatigue & no energy, even with caffeine! I could literally sleep/lay in bed all day-no appetite either. This is my only complaint and can only guess that my lethargy is related to cephalexin? My infection appears to be getting better; have to take five more days of the drug. Female, aged 45, no allergies.

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