Overview

Penicillin represents one of the most important drugs ever developed. Its discovery in 1946 permanently changed medicine and set the stage for man’s ability to overcome what had previously been life-threatening infections.

Penicillin is effective in fighting infections in many places in the body including the urinary tract, lungs, ears, throat, skin and genital tract.

Penicillin V potassium is prescribed generically or under a variety of brand names including Beepen-VK, Betapen-VK, Ledercillin VK, Pen-V, Pen-Vee K, Robicillin VK, V-Cillin K and Veetids.

Side Effects and Interactions

The most common side effects of penicillin involve digestive tract upset. Nausea, vomiting and diarrhea can be troublesome for some people. A black hairy tongue, rash, sore mouth, and yeast infections of the mouth, anus or vagina are other potential adverse reactions.

Less common but possibly more serious side effects include anemia and blood disorders.

Report any symptoms to your physician promptly. Long-term treatment with penicillin-type antibiotics requires periodic monitoring by a health professional.

Penicillin VK may interact with aspirin and certain other arthritis medicines. In addition, oral contraceptives may be less effective in combination with this antibiotic.

Check with your pharmacist and physician before taking any other medicine together with Penicillin VK.

Special Precautions

Anyone who is allergic to penicillin-type antibiotics must generally avoid such drugs like the plague. 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.

If you are allergic to penicillin and you ever have to go into the hospital, make sure a sign is placed over the bed alerting hospital personnel to penicillin allergy.

Taking the Medicine

Penicillin VK resists acid breakdown in the stomach so it may be taken with food if it upsets your stomach.

However, for maximum absorption take this antibiotic on an empty stomach. That usually means at least one hour before meals or two hours after eating.

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  1. Hambeleleni H.
    Namibia
    Reply

    I have been taking so many antibiotics and now I am having a stomach problem and breathing. Sometimes I feel like vomiting. Itching the whole body, headache, saliva all the time in my mouth. Heart burning. Please help me. Other thing my stomach is always moving and goes up pressing my heart.

    • Terry Graedon
      Reply

      A reaction like this should be reported to the doctor who prescribed the antibiotic.

  2. Lida
    Reply

    I had recently started to take penicillin for a mild ear infection, exactly 2 days ago. Now I have a abdominal pain but more towards the low abdominal and some discharges from the vagina with a little bit blood.. Transparent …Is so rare…so I have decided to stop taking penicillin vk… And try to deal the ear infection… What is happening with me?

  3. Alorna
    Reply

    Hi everyone,
    Got diagnosed with tonsilitis on Thursday and immediately started taking penicillin. I was so happy as I’m at university and I thought that I would start to feel better by day 2. However, the first weird thing I noticed was I was sneezing a lot, like literally 8 times in an hour and they were those hard chest sneezes that made my eyes water like mad. Does anyone know what’s going on ? I should mention 3 days before diagnosis I developed a severe runny nose I have went through 2 toilet rolls in 3 days, it’s so embarrassing I couldn’t even go out as the mucus was so thick and bubbly etc (tmi) please help I feel like I am dying is this meant to happen ? (PS I take 2 tabs 4 times a day)
    Thanks

  4. Pamela
    Reply

    I to have arthritis problems now and believe they stem from penicillin. I’m allergic to it and my doctor didn’t believe me. I was in the hosp. for three days on an i.v. of pen. I was 18. Now I’m 50 and the bones are deteriorating in my feet. I’ve also been told I have chronic infection. Also diagnosed with psoriatic arthritis. I can’t find anyone else with the same symptoms but this is close. I’m so hoping to find someone who has been in my shoes to get some good advice. Most doctors don’t believe me. This must be very rare.

  5. margie
    Reply

    I have been thinking of the side effects of long term use of penicillin as I too had rheumatic fever as a young child and totally bed ridden for almost 6 months and then a daily dose of penicillin for years after…it sounds like others with similar experiences have suffered arthritis, which thankfully I don’t have…..but someone once warned me that overuse of antibiotics can cause pernicious anemia. am looking forward to any info on this topic..

  6. JTA
    Reply

    Okay so I had the same rash thing how up after being on antibiotics for 4-5 weeks they just kept prescribing one after the other till something made it go away I went to my dermatologist since it was a rash/discoloration and he told me prolonged periods of antibiotic use can actually do more harm then good it not only destroys whatever bacteria is attacking your immune system but also the good bacteria keeping your body stable that being said the good bacteria also controls yeast levels in your body an overgrowth of yeast causes itchy skin scalp and skin discoloration fluctuating body temps etc.
    I advise you to go to a local drug store and pick up a local probiotic and start taking it and if you need a little extra umph go to a dermatologist hell prescribe you some medicine to balance out your bodies good and bad bacteria.

  7. TG
    Reply

    I’ve been taking it for penicillin vk for 4 days and the burning sensation I feel in my stomach and chest is unbearable. My butt burns too when I move my bowels. I called the pharmacist and endodontist and they both told me to stop taking it. So thankful. I hope I can still get my root canal done.

  8. Mrs Simms
    Reply

    Can you tell me if taking penicillin v long term can have effects on your bowel? My mother in law has been taking it constantly for 6 years, for cellulitis in both legs, (she also has lymphoedema in both legs). She has had diarrohea for 3 weeks, and is now in hospital. The doctors are saying they think its from taking this for so long, but would this type of symptom develop after 6 years?

  9. Anthony
    Reply

    I been on penicillin VK and now have really bad stomach cramps an loose stools. I do have ibs but this is really bad and the pain is indescribable.
    Is this common? Do I need to tell me GP?

  10. Candy413
    Reply

    I am a diabetic and I went to the hospital because I had a toothache and I was put on penicillin vk 250mg and a pain medication. I was fine at first but days later I have been having stomach pangs. I have not been able to keep food down or it feels like its gonna come back up. I also noticed I am itchy in my private areas front and back. I stopped taking the penicillin medication because it makes me feel worse and seems to be adding to some other issues aside from why I started taking it in the first place. Is this a normal side affect? and how long can I expect to feel bad?
    PEOPLE’S PHARMACY RESPONSE: You need to let your doctor know about this reaction. S/he will need to make sure the infection has cleared.

  11. nw
    Reply

    Thank you so much for your post. Went to dentist and advised that I needed a root canal as well and decided to put me on penicillin for 7 days prior to procedure. Had no problems taking this medication for 2 days. However, today (day 3), I’m dying. My stomach is in so much pain. But then again, so is my tooth! Actually contemplating not taking my meds. I thought I had a really bad bout of indigestion, but it’s lower, more towards the upper abdomen, than where it should be. Food sickens me right now, but I know I’m hungry. I will try taking the next dose with food (although doc recommended an empty stomach). Please tell me your root canal went well and that you began to feel better once you stopped taking the meds.

  12. J
    Reply

    I have been on the penicillin VK before and been fine, but this time I have been feeling/been sick after I take them and have this weird feeling in my stomach, not really painful more annoying! Should I stop taking them?

  13. ceh
    Reply

    I was prescribed Penicill VK as preliminary to a root canal which will take place next week. I was fine the first day or 2 & then realized the awful cramps & stomachache were being caused by this medication to the point I dreaded taking it each time. Could hardly drive to/from work & in order to coat my stomach have been eating a lot more than usual – not helping my diet! – just thankful that has been the only side effect. I now realize I should have slowed down & taken time to read the paperwork because I was too busy at first to do so.

  14. David
    Reply

    Had cancer- nonhodgkins lymphoma- and had spleen removed a little over year ago. Have been on penicillin since and am told will be on for five years. Doctor says that infection is now my worst enemy and more former cancer patients die of infectious decease than returning cancer. PS- test results show I am currently cancer free.

  15. m
    Reply

    I am a kidney/transplant recipient. I was given penicillin several months ago and I am allergic to pencillin bad. It nearly killed me. I was in the hospital and unable to work for sometime. My question is – is there any longterm affects for this. My body cannot fight against things like this because of the immunosuppresents I am on so I am wondering if there is anyway to tell if there is anything that can come up in the future as a result of this.

  16. rachael
    Reply

    OMG… I remember being kind of paranoid while taking Penicillin VK back in February. That feeling is gone know, thank goodness. Just last week I was put on Zithromax (generic form) and I noticed symptoms of hypoglecemia – my hunger pangs were accompanied by irritability, anxiety and weakness. Never felt that way before. Now, my joints are achy.

  17. lean k
    Reply

    hi, is it wrong to take pen v with doxycycline?
    PEOPLE’S PHARMACY RESPONSE: WE TRUST THE DOCTOR PRESCRIBED BOTH. THEY ARE TWO DIFFERENT TYPES OF ANTIBIOTICS AND WOULDN’T BE USED TOGETHER IN MOST SITUATIONS, BUT MIGHT BE APPROPRIATE UNDER SPECIAL CONDITIONS.

  18. PR
    Reply

    Worked 5* to annihilate my acute tonsillitis (when two other antibiotics failed to shift it) BUT gave me chronic diarrhea each morning which, apparently, is a known side effect. Worth it to get rid of tonsillitis! Better now :-)

  19. Cindi
    Reply

    Regina, did you get any answers? I, too, had Rheumatic Fever as a child and was put on Penn V K for YEARS. Now I have so many types of arthritis and other medical problems. Did you get any answers? If so, please share!

  20. JJ
    Reply

    I have recently started to take penicillin tablets for a mild ear infection. The same day I began with the treatment, I started developing a itch and mild rash in my genital area and scrotum, could it be that this is a reaction to the medicine or maybe an allergy? I have not ever had these symptoms. I stopped using the tablets now and will rather deal with the ear infection, than walk around with an itchy groin.

  21. M B
    Reply

    Don’t know if this will be any help, but here goes. I had my spleen removed in 1966 ( also for ITP) and I developed asthma at the same time, without taking daily penicillin. I once saw in a programme about Traditional Chinese Medicine that in China, if a patient presents with any breathing difficulty, then the first thing the doctor checks is spleen function.
    I had always been convinced there was a link and that seemed to confirm it. Unfortunately, our medical tradition looks at systems and symptoms separately from one another, and no doctor I have ever mentioned this fact to has known what to do with it.
    Also, I don’t know if anyone has ever mentioned this to you, but loss of spleen can interfere with the way that fat is metabolized (storing it rather than breaking it down) so you should watch your fat intake. All the Best.

  22. J G
    Reply

    I am an asplenic since having my spleen removed in 2002 for a blood disorder called ITP. I am now 53 years old and have been taking Penicillin VK long term since then. I have in the last year developed an irritating cough which the doctors are saying could be asthma. I don’t smoke and seldom drink. I recently had a chest X-Ray and they have said my lungs are clear. They have been monitoring a flow chart and say it is normal, but still I have this continued hacking cough. The doctor has now put me on another inhaler (the first was Salbutamol Sulphate) called Beclazone (Beclametasone Dipropionate) I have been taking this for a week now and it has made the cough worse.
    My breathing has become more laboured and my peak flow (which was as they say expectable at 350) has now gone down to 310. I was wondering if long time use of Penicillin VK could sometimes cause any kind of reaction like this. I work in a call centre so as you can appreciate it is not very good to keep coughing at people and apologizing all the time. Could you please help me? Regards JG

  23. regina v.
    Reply

    I am a 53 year old female with a childhood history of rheumatic fever at age 8 and 9. Both episodes had me bedridden for six months. I was on penicillin for ten years. I have digestive and arthritic issues now. Could the penicillin have compromised me?

  24. Linda K
    Reply

    Nicollette: do not despair, there are qualified doctors who can help, find one who will! sometimes you have to try several to find one who will listen. you could have an infection from the dental work that only certain antibiotics will get rid of but my skin got really dry and my scalp burned/itched after getting eye infection antibiotic, i think it was augmentin. Dentists can give us infections I had never heard about but they do it by breaking the skin in the mouth and infecting us with israellis actinomyceses. try looking that up.good luck.

  25. nicollette z
    Reply

    I am so mad, I am on the verge of killing myself and/or going to a hospital because of the crap I have been dealing with for the past year and a half.
    I have been on Amoxicillin for 2 weeks, then Augmentin XR for another, and now I am on Penicillin for another week due to my dentist who is a complete idiot and did something wrong when placing my bridge, that I was in the worst, AND I MEAN WORST pain of my life for over a year and a half.
    My question is: I have been losing much more hair from my head, and my body is itchy, and I am irritated, is this a side effect of all this crap in my body? Can I die or get extremely sick from all this poison (as antibiotics are poison right?) in my body? The reason why I have been on so many, is my dentist did not “know” what was causing my pain, so he “decided” that I had a “sinus infection” and sent me to my sinus dr. So I had x-rays, and was put on antibiotics until they knew for sure. Of course, I have nothing, as I am a very healthy, tofu eating, 31 year old mother of 2, with a good job.
    So, here it is now 5 weeks after starting antibiotics, and I feel as though I want to die, due to the pain I was in before another, more qualified dentist performed a root canal. But, my skin is itchy, and dry. I want to rip my hair out, as my scalp is peeling and burns, (kind of like if I bleached my hair for a month straight). I don’t know what to do, or who to ask, I just want to die.

  26. Paula Davis
    Reply

    Will long term use of penicillin vk effect your memory,and your bones?
    PEOPLE’S PHARMACY RESPONSE: WE ARE NOT AWARE OF SUCH EFFECTS.

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