Fluorquinolones are broad-spectrum antibiotics, meaning they can be used to treat a variety of illness such as UTIs (urinary tract infections) and respiratory infections. However, there is increasing evidence that this class of antibiotics is harming health.
What do fluoroquinolones do?
As you may have guessed from its name, fluoroquinolones contain the neuro-toxic element fluorine. Why is it used? Well, drugs with an attached fluoride molecule are able to penetrate all tissues, including the brain. The ability of the medicine to reach these tissues is all well and good – but the fluorine causes damage at the same time.

For example, it:
— Depletes energy reserves
— Disrupts collagen synthesis
— Inhibits antibody formation in the blood
In fact, it causes damage to: your good gut bacteria, nerves in the hands and feet (in fact, peripheral neuropathy has been listed as a side effect of fluoroquinolones since 2004), tendons, kidneys, liver, hearing, sight, and mental well-being. Milder symptoms include diarrhoea, vomiting, mild tendinitis, decreased energy, painless muscle twitches, memory loss and urgency of urination.
Even the FDA have issued warnings; given this was done in 2013, we might ask why such drugs are still being used. This petition letter on the matter was written in 1996!
NOTE: The topical formulations of fluoroquinolones, applied to the ears or eyes, don’t appear to share these risks.
How does fluoroquinolone damage occur?
Dr TR Plumb believes fluoroquinolone toxicity occurs through:
- Depletion of magnesium and disruption of cellular enzyme function
- Inhibition or disruption of the central nervous system GABA receptors
- Disruption of mitochondrial function and energy production
- Oxidative injury and cellular death
If you’re not sure what that all means, put simply, your cells get injured, your ability to produce energy is disrupted and your nerves stop working so well. You can see DR Plumb’s letter here.
Which antibiotics should I avoid?
Despite the known side effects, fluoroquinolones are still heavily prescribed in the US; I’m not yet sure about the UK and Channel Islands, except the prescribing indications for fluoroquinolones for children are severely restricted.
They are sold under such names as these, where the name in brackets is the one you see on the packet.
- Ciprofloxacin (Cipro); made by Bayer
- Gemifloxacin(Factive)
- Levofloxacin (Levaquin); made by Johnson & Johnson
- Moxifloxacin (Avelox); made by Bayer
- Norfloxacin (Noroxin)
- Ofloxacin (Floxin)