Americans love antibiotics. We tend to think of them as magic bullets, protecting us from life-threatening infections with almost no downside. But one kind of antibiotic called fluoroquinolones (FQ, quinolones or quins for short) has left many patients permanently impaired. Although most people can take such medications safety, others are left devastated.

A group called “Fluoroquinolone Toxicity 24/7 Forum” describes it this way:

“Fluoroquinolone toxicity has been like an atomic bomb exploding in their bodies damaging their muscles and scrambling their DNA to the point many are too sick to work, too weak to walk.”

We first began to suspect something strange was happening with FQs two decades ago. That’s when a reader of our syndicated newspaper column shared this experience after taking Floxin:

“I took it for a severe sinus infection followed by pneumonia last winter. After three days of utter misery and a rash on my back, I started hallucinating. Are there other people who have had a bad reaction to this antibiotic?” July, 1994

A few weeks later another reader shared a Floxin story:

“I too suffered a violent reaction to this drug. I took it for two days and became very nauseated. By the third day I not only felt listless, nervous and sick, but when I went to bed I couldn’t sleep and began having violent multi-colored hallucinations.

“After two nights of almost no sleep, accompanied by hallucinations, I asked my physician for something else. At first she was reluctant, but when she understood there was no way I’d take any more Floxin, she gave me a different prescription. I think Floxin is a frightening drug and I hope you will warn your readers that the side effects of Floxin may be more common than previously thought.”

These days some patients who have experienced bad FQ reactions refer to themselves as “Floxies,” no doubt because “flox” is part of the name of most FQs.

Stephen Fried, author of the book, Bitter Pills: Inside the Hazardous World of Legal Drugs (published in 1998), used the word “Floxed” to describe what happened to his wife Diane after she took the antibiotic Floxin for a minor urinary tract infection. After just one pill Diane had trouble talking, became disoriented and began hallucinating. She suffered serious neurological symptoms that persisted for years.

Over the last 20 years quinolone antibiotics have been prescribed to millions of Americans, often for relatively minor infections. Here is a list of common FQs:

  • Ciprofloxacin (Cipro)
  • Gemifloxacin (Factive)
  • Levofloxacin (Levaquin)
  • Moxifloxacin (Avelox)
  • Norfloxacin (Noroxin)
  • Ofloxacin (Floxin)

Physicians seem as awed by antibiotics as patients. It’s no wonder. Drugs like penicillin revolutionized medicine. People who once died from pneumonia or simple skin infections were cured in a matter of days. We love antibiotics too. Just read Joe’s account of how azithromycin helped him overcome a case of hard-to-treat asthma.

But some antibiotics, like the fluoroquinolones, can cause serious, sometimes permanent damage for susceptible patients. It took decades for the FDA to recognize the problem. It wasn’t until August 15, 2013, that the FDA warned physicians that FQs could cause irreversible nerve damage at any time during treatment, even after only a few doses.


  • Pain
  • Burning
  • Tingling
  • Numbness
  • Weakness
  • Changes in sensation to light touch, pain or temperature, or the sense of body position


  • Digestive distress, nausea, diarrhea, constipation, stomach pain, heartburn, vomiting
  • Headache, dizziness
  • Agitation, anxiety, irritability, restlessness, confusion
  • Insomnia
  • Tendon problems, tendinitis, tendon rupture
  • Retinal detachment
  • Allergic reactions, skin rash, anaphylaxis (life-threatening reaction requiring immediate medical attention!)
  • Super-infections, including C. diff diarrhea
  • Hallucinations, psychosis, seizures
  • Depression, suicidal thoughts or actions
  • Irregular heart rhythms, torsades de pointes, QT prolongation
  • Kidney or liver damage
  • Blood disorders
  • Arthritis, muscle pain, weakness

A long list of side effects is usually meaningless. People zone out after reading just a few symptoms. Drug companies are fully aware of this and have stopped worrying about listing dozens of serious side effects in their print ads or on television commercials. Although they once feared that a litany of serious adverse reactions might scare patients away, the truth is that most people ignore the scary messages and focus on the people having fun in the ads. The only way to truly understand the impact of FQ antibiotics is to read stories from real people:

“I took Levaquin three years ago for an infection in my leg. After three weeks of taking it, I had severe shortness of breath, ringing in my ears, pain walking and difficulty walking. The pain has never left, only gotten worse. I can only walk or stand for a few minutes at a time before having to sit.

“I have terrible insomnia, and with all the medical problems, have had trouble with being in a bad mood, as anyone would with all this pain. The doctor said he never heard of any problems with this medication, and acted totally surprised that I thought it came from Levaquin. He wanted to send me to a rheumatologist, as he said it wasn’t the meds, but maybe arthritis. You don’t just suddenly get arthritis!” Patricia

“I was prescribed Cipro for a UTI (urinary tract infection). After the very first pill (at night) I developed such pain in my right leg that I couldn’t walk or even straighten my leg. The next morning I immediately went to my doctor who agreed it was most likely the Cipro and never to take it again.” J.A.L.

“Cipro changed my life! Two years ago on day 6 of taking a high dose of Cipro I could no longer walk, had roaming pain and burning. Six months later I could finally walk without the fear of falling.

“Now two years later my legs will not support me if I try to stoop lower than the height of a chair. If I do light exercise for more a week I again have trouble walking.

“If I use my hand gardening for more than a short time I lose control of my hands – if I tried I could not pick up a feather after weeding. Yes, Cipro changed my life. Doctors tell me nothing other than to give it time. It feels permanent.” G.W.

“I was put on Levaquin over a year ago, and suffered much pain walking. I did not take the whole prescription, but enough to have done the damage, which is still giving me much pain in my feet and legs. I see now that this affliction will most likely be with me permanently. I told my doctor right away about this pain. She said that it sounded like tendonitis, but did not admit to me that it was mostly likely from the Levaquin she prescribed.” K.E.B.

“I was prescribed Cipro for a UTI 5 years ago at age 53. It was a 10-day prescription. Within a few days after starting the Rx I started getting migrating pains in my joints and muscles. The bottom of my feet started to burn and tingle. I couldn’t stand having anything on my feet or they would feel like they were on fire. My leg muscles got so weak I couldn’t stand for any length of time. There were other things too, I felt just awful.

“I called the prescribing physician, who told me these were normal side effects and would disappear once I finished the prescription. Well, they didn’t go away. It only got worse. Over the ensuing weeks I suddenly developed arthritis in both of my hands, wrists, knees and feet. My knees crackle badly now when I bend them and feel like I have sand in them. I have to wear ortho shoes. I never had one bit of arthritis before I took this drug.

“My doctor would never acknowledge that Cipro may have been a factor in the sudden development of all of these problems. I went to a rheumatologist who thinks I probably have mild RA now and put me on prescription anti-inflammatories. They help.

“I also saw a neurologist. He ran a bunch of neuro tests, which were all normal. He was the only one who acknowledged that Cipro could have played a factor. Now it’s five years later. Some of the issues have improved. The arthritis has not improved. I’m stuck with it now for life.” M.D.

“I have been suffering for over 16 years. No doctor believed it. I have every side effect mentioned. Then unfortunately after staying away from this class of drugs for 16 years, my surgeon felt that the Floxin solution she put in my head during a nerve decompression would not harm me. She was quite wrong. I have been so very sick since then and I am much older now so it is harder to convince doctors that it is not my age.

“Every bone, muscle, tendon and nerve hurts. My panic attacks came back full force and my eyes are so blurry. Brain fog, memory problems and trying to finish a sentence is disturbing as well. My stomach problems are worse than ever.

“Thanks for the article. Us ‘Floxies’ appreciate it!” Sherry

As mentioned above, most patients tolerate fluoroquinolones reasonably well. But a surprisingly large number of people are susceptible to serious side effects. Doctors are not quite sure why some individuals are vulnerable to neurological complications, tendon tragedies and inflammatory reactions.

We need a better understanding of the underlying mechanism behind FQ harm. Even with such awareness, we may not be able to predict who will react badly to medications like Ciprofloxacin or levofloxacin.

Patients and physicians must be aware of the early warning signs of fluoroquinolone toxicity. No patient should begin a course of treatment without a clear understanding of danger signals such as strange psychological symptoms or pain, burning, tingling, numbness and weakness.

Here is a link to the “Fluoroquinolone Toxicity 24/7 Forum.”

Share your own FQ story below. We want to know both the pros and cons of such drugs. Let others know about your experience.

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  1. BJ

    I was hospitalized for three days for a kidney infection I was given Levaquin intravenously for three days and by mouth 750 mg. per day for seven days on the fifth day my shoulders got very stiff and sore by day ten my legs were swollen stiff and so painful I couldn’t walk. I’m in a wheel chair and can’t work. This was a kidney infection why did this happen?

  2. BJH

    What can be done to overcome tendonitis that I believe was caused by Cipro?
    I am considering acupuncture. Any comment?

  3. L.C

    Took Cipro for a uti and it has devastated my health….. since last 5 years was in EXCELLENT shape hard rock body. spinning classes 5 days a week and hot yoga……does that answer your question Jennifer no other health condictions not one. Stopped my period also….. Ignorance is bliss for some….and let me tell you MD’s get very little pharmacology education. They do not understand the drugs and the the consequences to the human body. They are spoon fed what little they know from Pharm-Reps who profit from the sale stats…. wake-up… BigPharm supresses the science data and releases only positive results…..

  4. J

    “The other information we are missing, regarding these online posts involving bad results, is what the individual’s underlying physical condition was prior to taking the medication. It is possible the symptoms they experienced might have been caused by the med, and possible the symptoms were caused by other reasons, but coincided with the taking of the med.”
    Most of us were recklessly prescribed these antibiotics for minor, non-life-threatening infections where infinitely safer antibiotics *could* have been used instead. What you’re alluding to with the above statement borders on victim blaming, and that is NOT cool. It is no accident that thousands of individuals share stories online of how they ingested these drugs and soon thereafter had their bodies fall apart on them in unthinkable ways. That is no accident & no small coincidence.

  5. J

    You enjoy playing Russian roulette with your health? Everyone’s threshold for these antibiotics is different, but if you continue to press your luck with them you eventually WILL get hit. It’s just a matter of when. No whammies, no whammies…

  6. DB

    I got Floxed for a Sinus infection that I didn’t even need antibiotics for!
    Diagnosis: Sinusitis on 5/29/14
    Prescription: 14 days of 500mg/day Levofloxacin, Methylprednisolone dose pack (I know I know, why did my Dr. do this to me?!?!?), Dymista nasal spray
    Reaction: Took first Levofloxacin pill at 12pm 5/30/14, started dose pack that morning. Diarrhea by 1pm, could barely walk down the stairs by 4pm because my legs were so sore/stiff. Stopped taking everything immediately. Talked to the doctor today and they said that it’s a side effect of the medicine and that things should be back to normal “in a few weeks.” Yeah, okay.
    24 hours after single pill: Woke up at 5am to a panic attack, sore/stiff legs all day
    48 hours after single pill: Barely slept the night before (maybe 4 hours in short bursts), leg pain wasn’t as bad..was able to walk much better in the morning but this afternoon my leg muscles were sore again
    Current symptoms: Dry mouth, knees/calves/ankles ache, calves constantly twitching, can’t stand or walk for very long, lots of popping in my legs and arms, stomach ache and general lack of appetite
    Currently drinking lots of water with lemon, taking Epsom salt baths nightly, trying to eat a “clean” diet with lots of fruits and veggies. I take One-a-Day Men’s multivitamin in the mornings. I know I need to get more magnesium in me.
    I’m hoping these symptoms don’t get any worse… I generally feel OK just am scared that things will get worse.

  7. J.T.

    Several years ago I was prescribed Floxin. I took the first dose at bedtime. At 2:00 a.m. I woke up hallucinating that giant bats were flying around my room. Scared the heck out of me. Interestingly, my older sister who was a pharmacy rep at the time warned me not to take it. I shrugged her comments off as nonsense. This little brother had to learn the hard way. It was terrifying. Absolutely terrifying.
    It just makes me sad. Why we even have to go through these experiences in the first place. Every time I hear the FDA mentioned, I simply shudder. Perhaps someone will expose the FDA similar to what has happened at the VA.

  8. VS

    As you stated: “The anecdotal information is helpful, but limited.” Only this is real human body reaction in life situation. Not controlled experiment. All material published in the peer review journals (related to long term effects of medications) – are review of material which is published previously – from words of doctors whom have no time to talk to patients because (not because they do not know how) of business pressure. If you read any experimental article you can find subjective approach to the design of the experiments and interpretation of the material. In my experience – you almost never can find material which clearly explains dosage, reasoning for length and technicality of the review or experiments.
    Modern model for experimental model do not include preparatory phase and most likely will be limited by monetary fund. Can you tell this to your patient? Or can you limit reaction of the medication by 30; 60; 120; days? Can you find any experiment which trace whole cell and whole body effect of medications? Very few individuals, capable to explain, its own feelings especially in sentences for public use.
    It is why these types of publications needs to stand distant from the publications where human interventions are create environment for outcome.

  9. Sherry

    SR, please don’t take any more Fluoroquinolones! Even though you were OK the first round or perhaps 2, it accumulates in your body and next time you may not be so lucky. Listen to your body for symptoms even as far as one year out. It only takes one pill, or one ear or eye drop to get you sick, so please again, take another drug unless you are on deaths door.

  10. Sherry

    Oh dear Marilyn. I am very glad that YOU have not been affected by Cipro, but there are many people who haven’t put two and two together that these drugs are causing many other problems that weren’t there prior to them taking these drugs. It doesn’t necessarily happen while you are on the drug, but even a year later. Also, this drug accumulates in ones body, so you might be ok the first few times, but be careful, the next time can be the one that will do you in.
    People need to be informed that this group of drugs has the potential to cripple them in physical and mental ways. Please do not downplay it. I have been sick for 17 years now (yes 17 years) and I watched my father hallucinate for 6 weeks after being given Levaquin and then he died. Good luck to you, but if it was me, and I have been safe from being harmed from Cipro, I would quit while I was ahead! Just my opinion.

  11. R. Terry

    Levaquin left me with permanent severe Peripheral Neurapathy.

  12. Lisa B.

    People love to categorize. Fluoroquinolones kill bacteria, so they are categorized as antibiotics. But they have little in common with benign antibiotics like tetracyclines or penicillins. They have more in common with chemotherapeutic drugs.
    In fact, they ARE chemotherapeutic drugs. They are topoisomerase interrupters – all of the other topoisomerase interrupters are chemo drugs. They kill tumor cells and are used to treat cancers – showing that fluoroquinolones not only kill bacteria, but they also kill eukaryotic cells. They do severe damage to mitochondria and cause chromosomal abnormalities. They can cause horrible adverse effects.
    I really wish that people would quit thinking of them as simple antibiotics. Fluoroquinolones are far more dangerous and destructive than any other kind of bacteria killing drug.

  13. SR

    I am really sorry for the terrible response others have had with these antibiotics. I have taken Cipro and Levaquin & have never had a bad reaction. I rarely have to take antibiotics but next time I need to, I will pay close attention to any response, thanks to all of your input.

  14. JWB

    Thank You for all that you do, I was put on Levaquin for an ear infection,
    It made me nauseated, and I told my Dr. I wanted something else, He said that Levaquin was one of the good drugs, but I refused to take anymore, and he gave me something else,
    Many years ago I had an old Dr. in New Jersey tell me that Red Heads like me are just as senstive on the inside as they are on the outside, and told me to be careful what I take, I tell my Drs. that to this day, but sorry to say I have still had some bad experience, God Bless you for all you do,

  15. Annie K.

    I received Levaquin IVs for an infection over the course of 3 days. About one week later I began having cognitive difficulties (confusion, memory impairment)and nerve pain in my wrists. I also developed an incredible sensitivity to sunlight on my face, causing red burning skin and rashes.
    I was given the Levaquin IVs in Sept. 2010. It took almost two years for all the symptoms to disappear.

  16. Donnie

    My mother was given Levaquin and suffered terrible hallucinations, among other serious side-effects. There was talk about putting her in a nursing home. I found a list of side effects from Levaquin, and the doctor took her off of it. She got over the hallucinations fairly soon, but other adverse reactions to the drug persisted.

  17. Ellen C.

    In 2004 I was given Levaquin for a kidney infection. I developed hallucinations and four different cardiac arhythmias, one of which is still with me.
    Even after that experience and my inclusion of it in my personal medical history, doctors still try to give me one of the fluoroquinolones and I have to point out the side effects and argue with them. I can understand why doctors do not know side effects. There are so many drugs out there that no one could keep up with that.
    But what I do not understand is their “set in cement” attitude toward warnings about specific drugs and their unwillingness to listen to the FDA and their own
    medical experts and organizations. The average physician, especially here in Texas, seems to be about 20 years behind the learning curve. A really good pharmacist is the best friend to have these days.

  18. Jay H.

    Oh, yeah–and half of my hair fell out. Nobody told me about THAT side-effect before I took it, either!

  19. TA

    I was put on CIPRO after surgery and it nearly killed me. I got extreme pains in my abdomen and my hair fell out by the handful.s We were on a plane to Utah and my spouse spent the whole time picking up handfuls of hair off of my shoulders. It was ghastly…..thanks to my pharmacist we traced it to CIPRO… it is on my charts as an allergy. However, wouldn’t the other similar drugs mentioned above be just as dangerous?
    People’s Pharmacy response: You should definitely tell any doctor about your reaction to Cipro. Other fluoroquinolones might also affect you badly.

  20. Carole G.

    A few years ago, Dr. had me using Carac on face for skin cancers for almost 3 weeks, got 2nd degree burn on face, His RX was Cipro, made me itch. Next day pain was so bad I went to Emergence room, they used Silverdine cream on face. Almost immediately I was itching over entire body. They gave me something for itching (told them about Cipro and told me to discontinue it). Next day I cut an Aloe leaf from yard and put gel over entire face after googling and finding it has anti-bacterial properties. Fresh Aloe saved the day! No more anti-biotics, don’t know why I thought Meds would work better than a plant I’ve used in past for kitchen cuts, burns.

  21. Jay H.

    I took Cipro 8 years ago and was never informed of possible side-effects–because they weren’t known yet. I’m STILL experiencing iatrogenic inflammation of my tendons and ligaments–particularly my Achilles’ tendons. It can be crippling–and I have a part-time gig as a freakin’ fitness instructor! During one flare-up I also experienced a partially detatched retina, and during other episodes of swollen tendons I experienced a peculiar muscle weakness that felt like I was coming down with the flu, and a persistent aching in my joints. These episodes can linger for WEEKS before they resolve.

  22. cara

    If you think a drug is bothering you, stop taking it. We are concerned about upsetting doctors, but it’s our bodies, our health. I know some drugs can’t just be stopped. They have to be stopped gradually, so go off of drugs carefully.
    I was on Actos. I knew that drug was giving me problems. No doctor would take me off of it. I finally went to a naturopathic doctor. I knew I was dying. He looked up the drug and learned that indeed Actos could cause my problems. Within about three weeks after stopping Actos, I was healed of all my symptoms.
    That was seven years ago, and I am healthy. I had been given six months to live, by three doctors and a hospital ER doctor, so I’m very grateful for my naturopathic doctor who listened to me and cared.
    I can’t state enough be careful going off drugs, but if you think a drug is making you ill go to someone who will listen and direct you to a safe way of getting off the drug. Listen to your body. Know your body.

  23. Jennifer

    Have any scientific studies been done, and if so, what are the findings regarding numbers or percentage of users who have adverse reactions? Regarding the website comments you quote, if makes more sense that people who have extreme reactions to the drug will take the time to post their bad experience. My guess is, it is rare for an individual who had no problems to even bother looking up such a site, let alone post their ‘good’ result.
    The other information we are missing, regarding these online posts involving bad results, is what the individual’s underlying physical condition was prior to taking the medication. It is possible the symptoms they experienced might have been caused by the med, and possible the symptoms were caused by other reasons, but coincided with the taking of the med.
    For instance, if one experiences a bout of diarrhea one day, it does not mean it was necessarily caused by something you ate that same day, or the day before, or at all. There are other causes of diarrhea, but often times we assume it was caused by something we ate.
    I’ve taken Cipro twice in my life, once during the time period when I was undergoing chemotherapy for breast cancer. I had no noticeable side effects either time. I do recall being advised of numerous possible side effects. My recollection is my doctor stated the longer an individual took it, the more likely side effects would occur. I believe I took a very short course of Cipro, but can not recall how many days’ worth. That was three years ago.
    Maybe you could take one extra step for your readers, and cite and discuss some scientific studies regarding bad side effects of these drugs. The anecdotal information is helpful, but limited.
    People’s Pharmacy response: You are quite right that people who have had bad experiences are FAR more likely to share them as a warning to others. Fluoroquinolones remain a mainstay of medical care and will probably continue to do so. They do help treat many serious (and are used for some not so serious) infections. People do need to be aware of the potential side effects. It is good that your doctors were careful to inform you.

  24. GFH

    I was put on high dose Cipro and Flagyl, combined, for an acute colon infection with suspected diverticultis in 2010. After three days I began hallucinating and started to panic. The doc put me on a high dose of amoxicillin which fortunately knocked out the infection. Most physicians I have mentioned this to think it was the Flagyl, but I am not convinced.

  25. VW

    I took Avelox and this is what it left me with: rapid AFib for 18 months, immediate stage 3 kidney disease, monoclonal gamopathy, brain fog, hearing loss, neuropathy, ringing in my ears. rosacea, and then last summer all the ligaments in my foot stretched out and I had major surgery on my foot.
    I now have a plate in my foot and about 14 screws. I took Avelox in 2008, so it continues to cause damage, I have no idea what’s ahead of me. I had a physical two months before I took it and I was completely healthy, as I had been my whole life. Up until 2008 I was in great shape – ate right, exercised my whole life and was biking twelve miles a day. So my life has become a new life that I have had to adapt to, I appreciate life and take nothing for granted.

  26. Judy K

    2 doses of Cipro taken over 1 day in December, 2005, have taken away my life. I am still suffering (May, 2014) and it has been a horrible, painful journey. Issues have changed over time, but they re-cycle. To date, I have or had enormous burning pain over my entire body (some have likened it to chemo pain) severe GI issues, vision issues (nearly blind), have had at least 1 TIA, walk with a 4 pronged cane, have had many CNS problems including sleep disturbances from insomnia to nearly constant sleep which also cycle, and of course the connective tissue/tendon/ligament/muscle issues, which range from pain to rupture. I have just had a ramp installed in my home as I will soon need a motorized scooter. I have not been able to walk stairs since the day I took the 2 pills. 8 1/2 years ago ! I was FINE the day before I took the pills. Other than a suspected UTI, in fact I had just finished packing and moving the contents of a condo cross-country. Funny, turned out I did not have a UTI, but the doctor was being cautious. I have since found out that Cipro is not to be given to those over 60, I was 62 when I was ‘floxed’.

  27. Marilyn

    I have taken Cipro for years and NEVER have had a problem. Everyone has different reactions to ANY medications and I think it is wrong to say Cipro is a bad drug.

  28. Edna

    I experienced severe chest pains – like my chest had solidified – while taking Cipro, but I ceased using it at that time – it was scary. My doctor said he had been prescribing Cipro for 20 years w/o any complaints, but this is hard for me to believe! My son (54) was prescribed Cipro just recently for a foot infection and experienced the same reaction and even though I told his medical professional, he still prescribed it. My son’s problem was misdiagnosed – it was not an infection.
    I am losing faith in the medical profession – they are just after the money!

  29. Mat

    My hearing loss of results of antibiotics. Please avoid antibiotics whenever possible. Thank you.

  30. Sherry R.

    JOE, thank you so much for writing about this group of antibiotics once again and for writing about our group mentioned above. There were 50 of us who represented the voice of thousands in DC a few weeks ago meeting with Senators and the Senate Health Committee to stop the madness.
    Hopefully your readers will find our group on Facebook amongst others that are there to help them cope with this poisoned life we have been given! Sherry

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