Fluoroquinolones: Prescribed Poisons

Mitochondrial Damage and the Silent Epidemic of FQAD

It’s time for some radical authenticity.

I was poisoned by an antibiotic called Levaquin (Levafloxacin). It is among the fluoroquinolone family, along with Bayer’s more widely recognized version, Cipro (Ciprofloxacin).

Millions of people are severely affected by these drugs, landing in wheelchairs, or unable to function, or dead. And yet so few have heard about them. So, let’s talk about it.

Obligatory disclaimer: I am not a doctor. I have, however, thrown my entire being for over three years into researching and understanding the mechanisms and nature of the damage from these drugs, because, in a very real sense, my life depends on it.

History and Mechanism

In 1962, Lesher et al. accidentally discovered nalidixic acid while synthesizing chloroquine, an antimalarial drug. Nalidixic acid became the first quinolone antibiotic, used primarily for UTIs¹.

In 1977, scientists at Kyorin Pharmaceutical Company modified the quinolone structure by adding a fluorine atom at the C-6 position. This led to the creation of norfloxacin, the first fluoroquinolone (FQ)². The addition of fluorine significantly improved the drug’s ability to penetrate bacterial cells and inhibit DNA gyrase and topoisomerase IV, enzymes essential for bacterial DNA replication and transcription³. This leads to DNA strand breaks and ultimately bacterial cell death.

This increase in power comes, however, at a price to human cells.

Collateral Damage: Tendons and Mitochondria

Human mitochondria contain similar DNA-processing enzymes. This makes them vulnerable to unintended “fluoroquinolone interference”⁴. This collateral damage takes two principal forms:

1. Tendon Damage:

   FQs interfere with collagen synthesis and increase collagen degradation by up-regulating enzymes called matrix metalloproteinases (MMPs)⁵. This combination is especially potent and destructive to tendons, which are made mostly of type I collagen. This is why torn Achilles’ and other tendon injuries are well-documented side-effects of FQs (although the damage is body-wide)⁶.

2. Mitochondrial Damage

   FQs impairs complexes I and IV of the mitochondrial electron transport chain (ETC)⁷. Damaged mitochondria produce less ATP — the fuel of the cell — and cause oxidative stress. Specifically, when they attempt to generate ATP, the broken ETC fails and spits out Reactive Oxygen Species (ROS)⁸. The ROS then damages the surrounding tissue: whether heart, neuron, muscle, liver, immune, or hair follicle.

Difficult to Diagnose

Because every cell in the human body contains mitochondria, with the exception of red blood cells, an individual who is affected by FQs, can present with symptoms across any number of systems.

Because only recently has research acknowledged this collateral damage, bestowing it the name of “Fluoroquinolone Associated Disability” (FQAD), very few physicians or even specialists are aware of this possibility. Symptoms may appear weeks to months after the FQ was taken, making the association difficult.

Thus, when a patient walks in (as I did) and complains of weak muscles, sore tendons, neuropathy, visual disturbances, cardiac arrhythmias, and insomnia, most doctors dismiss symptoms and say (as they did) either “this guy is crazy” or “this is way out of my wheelhouse.”

As a result, there is little to no data on just how many people have been damaged by these drugs. One can find numerous reports of celebrities or athletes dying or being injured by the antibiotic⁹.

Regulatory Warnings Ignored

There were, however, enough people who did suffer immediate reactions that regulators have been forced to issue warnings¹⁰:

• In 2008, the FDA added a black box warning for risk of tendinitis and tendon rupture

• In 2013, the FDA added a box warning for risk of irreversible peripheral neuropathy

• In 2016, FDA announced that fluoroquinolones may cause “disabling and potentially permanent side effects” affecting the tendons, muscles, joints and nervous system. The agency said the drugs should not be used to treat certain types of “uncomplicated” infections.

• In July 2018 the FDA issued new warnings that fluoroquinolones could cause dangerous drops in blood sugar and serious mental changes, and

• In December 2018, the agency warned that the drugs can cause ruptures or tears of the aorta.

• In 2024, the UK MRHA cautioned fluoroquinolones must only be prescribed when other antibiotics have failed, will not work because of antibiotic resistance, or are unsafe to use for an individual patient.¹¹

Notwithstanding these advisories, FQs are still prescribed over 14 million times per year¹².

Some patients may experience only a subset of effects, resulting in a misdiagnosis as Chronic Fatigue Syndrome (CFS), fibromyalgia, neuropathy, anxiety, or many others¹³. And, until ICD10 went into use in the US in 2015, there wasn’t even a diagnosis code for FQAD. This further complicates the question of just how many people have been damaged.

But, given 14 million prescriptions a year, with some estimates of adverse reactions in 0.5-1.5% — and severe disabling effects (FQAD) in up to 0.1-0.3% — we can ballpark that up to patients experience 70,000–210,000 adverse reactions each year, and 14,000–42,000 people are permanently disabled by these drugs each year¹⁴¹⁵¹⁶. Others put the estimate for severe effects at 3-5%, meaning potentially 420,000–700,000 Americans severely harmed (some permanently, some fatally) annually¹⁷.

And yet, Bayer’s Cipro and others continue to be prescribed every day, in many cases where safer drugs could suffice.

Susceptibility & Biological Terrain

Not everyone reacts the same to these drugs; lifestyle factors and terrain conditions influence how these molecules affect one’s system. A 2023 Baylor College of Medicine study looked at the effects of ciprofloxacin in mice:

Healthy control mice in the study suffered no notable aortic damage when they were given ciprofloxacin. But nearly 80% of the mice that had been fed a high-fat diet and given drugs to cause mild aortic disease developed severe aortic destruction when they were given Cipro, and 15% of them died after suffering an aortic rupture.

This suggests even small vulnerabilities can drastically increase the risk of a catastrophic outcome — and it’s not always clear in advance how a given patient might respond.

Conclusion

I’m not saying these drugs are inherently evil — they have saved lives where other drugs have failed — but the cost of their deployment in the human system is exorbitant. And given this, their use is entirely inappropriate in the vast majority of cases.

In some ideal reality, perhaps the medical system would self-correct. But, in our reality—or at least, in the meantime—I will do what I can, three years into my recovery, to spread the word. I will be following up with a post on recovery strategies.

Research and understand anything you put in your body — whether it’s a syringe or a pill.

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Have you been affected by a fluoroquinolone antibiotic? Stay tuned for a post on recovery, and I’d love to hear your story. Comment below.

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I very much welcome your thoughts — comment below. 🙏

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1. Nalidixic Acid—Mode of Action (1975), https://link.springer.com/chapter/10.1007/978-3-642-46304-4_12

2. History of Discovery and Development of Norfloxacin; a New Quinolone Antimicrobial Agent (2020), https://www.jstage.jst.go.jp/article/jjhp/55/2/55_115/_article/-char/en

3. Topoisomerase Inhibitors: Fluoroquinolone Mechanisms of Action and Resistance (2016), https://perspectivesinmedicine.cshlp.org/content/6/9/a025320.full.pdf

4. Ciprofloxacin has dramatic effects on the mitochondrial genome (2018), https://www.sciencedaily.com/releases/2018/10/181001101943.htm

5. Contrasting effects of fluoroquinolone antibiotics on the expression of the collagenases, matrix metalloproteinases (MMP)-1 and -13, in human tendon-derived cells (2005), https://academic.oup.com/rheumatology/article/44/12/1514/1788332

6. Fluoroquinolone Use and the Risk of Collagen-Associated Adverse Events: A Systematic Review and Meta-Analysis (2019), https://link.springer.com/article/10.1007/s40264-019-00828-z

7. Chemical Proteomics Reveals Human Off-Targets ofFluoroquinolone Induced Mitochondrial Toxicity (2025), https://onlinelibrary.wiley.com/doi/epdf/10.1002/anie.202421424

8. Mitochondrial reactive oxygen species cause major oxidative mitochondrial DNA damages and repair pathways (2020), https://link.springer.com/article/10.1007/s12038-020-00055-0

9. ‘Killer’ antibiotic that’s STILL being prescribed to 15m Americans a year: Widow of singer Bobby Caldwell reveals how pills he was prescribed for a COLD left him paralyzed and with ‘unbearable’ nerve damage - leading to his untimely death (2024), https://www.dailymail.co.uk/health/article-13115607/Bobby-Caldwell-wife-fluoroquinolone-antibiotics.html

10. https://www.consumernotice.org/drugs-and-devices/fluoroquinolones/

11. Fluoroquinolone antibiotics: must now only be prescribed when other commonly recommended antibiotics are inappropriate (2024), https://www.gov.uk/drug-safety-update/fluoroquinolone-antibiotics-must-now-only-be-prescribed-when-other-commonly-recommended-antibiotics-are-inappropriate

12. Fluoroquinolone Toxicity Study, https://fq100.org/

13. Fluoroquinolones-Associated Disability: It Is Not All in Your Head (2021), https://www.mdpi.com/2673-4087/2/3/17

14. High risk for life-threatening adverse events of fluoroquinolones in young adults: a large German population-based cohort study (2025), https://bmcmedicine.biomedcentral.com/articles/10.1186/s12916-025-03919-0

15. Comparative Analysis of Adverse Drug Reactions Associated with Fluoroquinolones and Other Antibiotics: A Retrospective Pharmacovigilance Study (2025), https://www.dovepress.com/comparative-analysis-of-adverse-drug-reactions-associated-with-fluoroq-peer-reviewed-fulltext-article-DHPS

16. Analyses of Adverse Drug Reactions to Fluoroquinolones in Spontaneous Reports Before and After the Referral and in Clinical Routine Cases (2025), https://link.springer.com/article/10.1007/s40268-024-00499-x

17. Fluoroquinolone Toxicity Study, https://fq100.org/