Bitter Pill: The Dangerous Side Effects of Fluoridated Antibiotics

Story at-a-glance

  • Fluoroquinolones are antibiotics that contain fluoride, which allows them to penetrate into sensitive tissues like your brain and central nervous system
  • Fluoroquinolone antibiotics are known to cause severe tendon damage and/or rupture, and permanent nerve damage in hands or feet
  • Other side effects include acute liver toxicity, acute kidney failure, psychiatric side effects, hearing or vision problems, and other health problems—many of which are permanent
  • Fluoroquinolones should be reserved for treating only the most serious bacterial infections that remain unresponsive to other treatments. Avoid them if at all possible


This is an older article that may not reflect Dr. Mercola’s current view on this topic. Use our search engine to find Dr. Mercola’s latest position on any health topic.

By Dr. Mercola

Fluoroquinolones are among the most dangerous drugs on the market and should be avoided unless your life depends on it. Despite their dangers, they're the most commonly prescribed class of antibiotics in the United States... In 2010, Bayer's top two fluoroquinolones (Cipro and Avalox) brought in $1 billion in sales.

That same year, Johnson & Johnson sold $1.3 billion-worth of its drug, Levaquin. All antibiotics carry a risk of side effects, but fluoroquinolones are in a class by themselves when it comes to potential health risks.

No other antibiotic carries as high a potential to cause serious, permanent injuries and even death, as the fluoroquinolones do. Despite their higher than normal risks, doctors frequently prescribe them as a first line of treatment even for mild infections. Always ask your doctor if there is a safer alternative.

And, adding insult to injury, most victims claim they were never warned that there are dire adverse effects associated with these antibiotics. I strongly advise you to educate yourself about the risks of fluoroquinolones, and refuse any prescription for these drugs unless absolutely necessary.

What Makes Fluoroquinolones So Dangerous?

Fluoroquinolones have fluoride as a central part of the drug. Fluoride is a known neurotoxin, and drugs with an attached fluoride molecule are able to penetrate into very sensitive tissues, including your brain.

The ability to cross the blood-brain barrier is what makes fluoride such a potent neurotoxin. Fluoride also disrupts collagen synthesis, and can damage your immune system by depleting energy reserves and inhibiting antibody formation in your blood.

According to Todd R. Plumb, M.D.1--a physician and fluoroquinolone victim—fluoroquinolone toxicity appears to be functional, not structural, as structural abnormalities are not typically seen on the radiological studies of patients with fluoroquinolone toxicity. Based on the available research, he cites the following four possible mechanisms of harm by fluoroquinolones:

  • Inhibition or disruption of the central nervous system GABA receptors
  • Depletion of magnesium and disruption of cellular enzyme function
  • Disruption of mitochondrial function and energy production
  • Oxidative injury and cellular death

Bitter Pill features three victims whose lives have been shattered by the long-term health effects of fluoroquinolones. Placing the blame squarely on the drug maker, one of them says: "[These side effects are] not something they're just finding out now. These people are criminals. They belong in prison for the rest of their lives."

Dr. Terence Young, MD, also featured in this video, lost his 15-year old daughter to a lethal drug effect in 2000.

Channeling his grief into finding out how that could happen, he says he discovered "corrupt practices that prevented doctors and patients learning what the true risks of prescription drugs were. And the reason that's happened is because of this incredible marketing power of the pharmaceutical industry."

Beware the Serious Side Effects of Fluoroquinolones

Last year, the US Food and Drug Administration (FDA) finally issued a warning that fluoroquinolone antibiotics, taken by mouth or injection, carry a risk for permanent peripheral neuropathy.2

Peripheral neuropathy is nerve damage in the arms and/or legs, characterized by "pain, burning, tingling, numbness, weakness, or a change in sensation to light touch, pain, or temperature, or sense of body position."

But the risk for peripheral neuropathy was noted in 2001, when Dr. Jay Cohen published documentation showing the following fluoroquinolone-related reactions.3 Adverse reactions of fluoroquinolones were documented in Europe as far back as the 1980s:

Nervous system symptoms occurred in 91 percent of patients taking fluoroquinolones (pain, tingling and numbness, dizziness, malaise, weakness, headaches, anxiety and panic, loss of memory, and psychosis)
Musculoskeletal symptoms in 73 percent of patients (tendon ruptures, tendonitis, weakness, and joint swelling)
Sensory symptoms in 42 percent of patients (tinnitus, altered visual, olfactory, and auditory function)
Cardiovascular symptoms in 36 percent of patients (tachycardia, shortness of breath, chest pain, and palpitations)
Skin reactions in 29 percent of patients (rashes, hair loss, sweating, and intolerance to heat or cold)
Gastrointestinal symptoms in 18 percent of patients (nausea, vomiting, diarrhea, and abdominal pain)

In a letter to his Congressman, Dr. Cohen wrote:4

"These severe reactions are occurring in patients who are usually healthy, active, and young. Most often, the antibiotics are prescribed for mild infections such as sinusitis, urinary or prostate infections. Most reactions occur very quickly, sometimes with just a few doses of the fluoroquinolone antibiotic. Reactions are acute, severe, frightening, and often disabling."  [Emphasis mine]

Despite persistent warning signs, the FDA didn't take action until 2008, at which point they added a black box warning about severe tendon damage. They waited another five years before issuing a warning about permanent neuropathy.

This is yet another sad example demonstrating that just because a drug is FDA approved does NOT mean it has a proven safety record. Fluoroquinolones have also been associated with the following health problems and adverse effects:5

Retinal detachment, which can cause blindness Disruption of collagen synthesis and collagen degradation,6 causing muscle, tendon, cartilage, and/or ligament damage Nausea and diarrhea
Acute kidney failure Hallucinations and/or psychotic reactions.  (About one-third of patients tend to experience some sort of negative psychiatric effect, such as anxiety, personality changes, or confusion) Hearing problems
Brain fog Painful rashes Disruptions to blood sugar metabolism7
Depression Phototoxicity Peripheral neuropathy
Seizures Heart damage Acute liver toxicity8, 9

PLEASE—Only Use Fluoroquinolones as a Last Resort

Dr. Cohen's documentation differs rather drastically with the drug makers' own data. The drug companies claim less than one percent of subjects in clinical trials suffered serious adverse reactions. That's a far cry from Dr. Cohen's data showing a vast majority of patients taking the drugs experience more serious symptoms.

According to Bitter Pill, about 100 Canadian deaths have been attributed to fluoroquinolones since 1985. Freedom of Information documents obtained from the US FDA reveal more than 50,000 reports of adverse reactions and 3,000 deaths. Dr. Young believes the full picture is undoubtedly far worse than that, since most doctors never report suspected drug side effects and/or deaths. Patients also rarely report side effects of drugs they're taking. Previous research suggests that actual reports represent about one percent of the reality.

If your doctor prescribes a fluoroquinolone antibiotic, please be certain that your condition warrants the risks. Fluoroquinolones should really be reserved for treating only the most serious bacterial infections that remain unresponsive to other treatments. While several drugs in this class have been removed from the market due to their deadly adverse effects, six remain FDA-approved for use in the US:

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

Get Into the Habit of Reporting Adverse Drug Reactions

If you believe you have experienced a reaction to a fluoroquinolone—or any other drug for that matter—please report it to MedWatch, the FDA's safety information and adverse event reporting program. It is vital that they hear from each and every one of you who has experienced an adverse drug reaction. This is a major impetus in getting dangerous drugs removed from the market, and physicians almost never report the reactions themselves so it's really up to you to help make sure dangerous drugs are taken off the market. MedWatch offers several reporting options:

  • Telephone 1-800-FDA-1088
  • Fax to 1-800-FDA-0178
  • File a report online
  • Mail a report (FDA form 3500) in a postage-paid envelope to MedWatch, 5600 Fishers Lane, Rockville, Maryland 20852-9787

Support for Fluoroquinolone Victims

Victims of fluoroquinolones damage are so numerous, they've banded together in a worldwide network, calling themselves "Floxies." Quite a few Floxies are in the medical field themselves (or were, before they were poisoned), and are on a mission to help fellow fluoroquinolone poisoning victims. This is how the documentary Certain Adverse Events came about. If you haven't already seen this film, I highly recommend it.10

For more information, you can also visit the following websites (there are many more in addition to these if you search by the term "fluoroquinolone"):


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