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.

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. Estelle

    Several years ago I was prescribed Cipro for a minor infection. After just one pill, I refused to take anymore. I knew instantly that it was not for me. It is now on all my records that I am allergic to it. I became terribly flushed and had pains that I knew I should not be having. Since then I have had severe arthritis and there are days I can barely walk. None of the doctors I have been to have asked if I had ever had reactions to these drugs. Today, reading this post, I wonder if my problems go back to that one pill. Doesn’t seem possible but now, I wonder.

  2. Nanant

    At last! the US government found out about it. The company that owns the quinolones shouldn’t have made them. they’re so ridiculous.

    • M

      Sure they found out, yet they are still prescribed. Just yesterday (Monday), the U.S. FDA released a new time bomb on the American public: Delafloxicin. Beware.

  3. Bobbie

    Really upsetting to read this many years after the fact. Dr to Dr to specialist to more specialized Dr, broke, still very ill, too much medication, too many diagnosis. Surgeries, 63 and in horrible pain daily. Thanking God tho for my grankids they make me smile!

  4. James

    Was diagnosed with Pneumonia and prescribed Levaquin. Took one pill and a few hours later got this weird rush of tingling/numbness that went through my arms into my neck. My arms got really weak and I could hardly raise them. But I was tired and it was early in the morning and I went to sleep. The next morning my arms were better but still felt weak but my neck was really messed up – hard to describe the feeling. Then I read the safety information that the Pharmacist gave with the prescription and saw the warning about numbness which led me to the Internet and to this site.

    So I went back to the Doctor and literally had an argument that a reaction had actually occurred. Everything that happened a few hours after taking the first dose was apparently a complete coincidence. She said ‘Levaquin is the best’. But she humoured me by writing a prescription for something from a different drug class.

    As I type this my arms are still weak and my neck is still messed up. I’ve had antibiotics throughout the years and aside from getting a rash when I was on Amoxicillin I’ve never had issues before.

  5. Betty

    Finally, the FDA admits that flouroquinolones can cause severe physical damage to the patient; the damage can be permanent, which is what I feel my situation is. I have been under doctors’ care for years now for neuropathy. Doctors knew less than you, Mr. Graedon. I have been screaming for years, and you certainly have written about this class of meds over the years. Your articles were my support. Thank you. (I wrote this originally to your general website before I found this article).

  6. Stu

    Two years ago after a three week course of Cipro I suffer from peripheral neuropathy. No one believes that the caused my problem. Literally stopped in my tracks with regards to physical activity. It is so hard living everyday with the pain, burning, coldness, numbness. Some days just don’t know how I make it through 24 hours. If I had only known. Thank you big Pharma for changing my life for the worse.

  7. Bonnie
    San Luis Obispo, California

    I took Levaquin for a respiratory infection in May of 2008. I started having problems with my right leg shortly after, but didn’t make the connection to the drug. Then in October of 2008, I was prescribed Cipro for a UTI and took one pill and could not move my arms or legs. I looked at the insert and noticed the black box warning of tendon ruptures which had only recently been put on fluoroquinolones. It was then I realized that I had taken the Levaquin earlier and was suffering from muscle pain and weakness. I have gotten progressively worse over the years and been to numerous doctors. I have yet to find one who will acknowledge the connection between this drug and my deteriorating condition.
    I do have a theory as to who is adversely affected by fluoroquinolones. I am hypothyroid.
    My daughter-in-law who has had a thyroidectomy and is on synthroid also had an adverse reaction to Cipro. Fluoride is an endocrine disruptor. Hypothyroidism may be an indicator of who should not be prescribed this antibiotic. I know it is contra indicated in elderly patients. I was 58 when it was prescribed to me. I would be interested to know how many Floxies are also Hypothyroid or suspect they are because with doctors using only TSH blood tests, a lot of hypothyroidism is undiagnosed.

  8. Lisa B
    Denver, Colorado

    Fluoroquinolone toxicity is far less rare than people assume. Delayed reactions and tolerance thresholds are’t taken into consideration when determining how many people react badly to these antibiotics. Also, as was mentioned above, doctors fail to acknowledge that multi-symptom, often chronic, diseases were caused by fluoroquinolone antibiotics. Adverse effects of FQs include many psychiatric issues like anxiety, depression and even bipolar disorder. Who would connect anxiety attacks to an antibiotic taken weeks ago? But they are connected. The microbiome is important. So are mitochondria. FQs wreak havoc on both.

    • Christine
      Denver, Colorado

      Lisa B.

      If I sound vague, it’s because I wish to respect your privacy as well as protect my own. However, I noticed that your comments were strikingly on point and relevant to an article by author Lisa B… on another site. I also noticed that you are in Denver, Colorado. So am I! I was wondering if we could communicate directly–think you will find my story that dates back to 2007 and is still percolating as I negotiate with defense counsel for Johnson & Johnson, et al (manufacturers of Levaquin) over a serious settlement offer. The “delayed reactions” aspect plays a huge role in some of my arguments and counterarguments (I am pro se at this time). If you and Lisa B. are the same person (ref article March 3, 2014), I will share contact info with you on that other site. I intend to participate on that site in any event.

      • Doug

        Christine, I am not posted on this site and my symptoms are identical. I would appreciate discussing with you further as I often feel alone in this, even though there are many of us. Been going through it since August and am starting to lose hope. Dr didn’t warn me at all (just avoid calcium) and Walgreens didn’t even ask if I had any questions (just “here you go”). I should know better as I work in Pharma and Med Supplies.


  9. Debbie

    In the early 90’s, I took Cipro for pneumonia and could not walk for 15 months. The pain was unbearable. I lost my job and was a single Mother. The pain disappeared out of nowhere. June 2009 I took Levaquin, 2 pills total. I was healthy, happy, good job and no problems in my life. Until the pill I had a mild chest cold. I was in the doctors office for 10 minutes and was prescribed Levaquin. Pill #2 caused burning, painful feet. I was going to the health club after work with a co worker while I thrived from working out we both noticed something was really wrong with me. I had a sudden inability to walk due to horrible pain. I had to quit working out. I suffered in pain in order to work, shop, and care for my ill Mother.

    I kept the pain to myself but slept as soon as work and dinner was done. Fatigue set in quickly and everything became worse even after seeing 12 different doctors to figure out why I wasn’t able to walk and why I was in so much pain. I got the usual plantar fasciitis, physical therapy, and orthodics… Each doctor who found me getting worse had no answer and I kept getting released. And was told do not rely on walker, use a cane so I could keep building strength and avoid atrophy. I was determined to care for my Mother and suffered through the pain. She passed on from pancreatic cancer and by then my sister had to step in. So from June 2009 until December 7, 2014 (presently) I have been in a wheel chair and cannot step down on my left foot. The severe pain and weakness has traveled from my foot through my whole left side of my body. I do not leave my home to socialize, shop, only for my doctor appointments due to pain flare ups and socializing in pain is not fun for me nor can I handle interaction. I cry daily, I am full of dread of the loss of my real self and all I worked for. I had achieved a good life that included being a Real Estate Agent. I was very successful and enjoyed my life after raising my son and lived my life with no obligations to anyone but myself and was happy. ALL if these dreams are gone. I am still hopeful but still do not understand how I went to a doctor I trusted to make me well and instead ruined my life in a very inhumane way. It is criminal to all of us who are suffering due to greed. Very sad state our country is in!

  10. Alan T.

    My wife was prescribed Levaquin at the end of Feb. 2014. Seven days into her dose her tendons tightened up throughout her body. She has been either in pain every day since, he mobility is limited, she has suffered through brain fog, and generally went from living a vibrant, active life to being bogged down with dealing with pain and trying to heal.

  11. Jim Bertholdt

    I’ve experienced side affects to several different
    FQ antibiotic drugs, namely severe diarrhea…I have a chronic colitis condition that is controlled by prescribed drugs…but my doctors do not seem to prescribe meds with no side effects when antibiotics are needed…any suggestions?

    • Hurt by Levaquin

      My life was ruined by Levaquin…

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