Quinolone Antibiotics: Risk Assessment required

Quinolone antibiotics (Fluoroquinolone to be precise) have been known to cause some potential harms. With the release of this article, The dark side of antibiotic ciprofloxacin,  last week I thought it would be good to put down a few thoughts.

Many people receive prescriptions for these powerful antibiotics.


The black box warnings are intimidating, although you wouldn’t know it by seeing the usage and trends above.


Before we get into the risk assessment part, lets glance at the how they can cause harm question, looking at a PubMed article:

What is the suggested pathophysiology of FQ-induced tendinopathy/tendon rupture?

The exact pathophysiology of FQ-induced tendinopathy remains elusive; however, some concepts have been suggested. FQs are synthetic antibiotics that act by inhibiting bacterial DNA gyrase (topoisomerase II). DNA gyrase is directly involved in DNA replication and cell division. Theoretically, FQs should not exert a negative effect on human cell lines because the affected bacterial enzymes have little homology with mammalian DNA gyrase. However, it is possible that FQs have a direct cytotoxic effect on enzymes found in mammalian musculoskeletal tissue.

The bolded emphasis is mine, but I believe it is critical, and a recurring theme that will be developed on this blog; looking at bodily systems in isolation, and the harm it can cause. This logic is precisely the same logic that allows glyphosate, the herbicide found in RoundUp, to be used ubiquitously in the food supply (which was originally applied for as an antibiotic). In that case, they show the shikamate pathway attacked is not found in human cells so it is fine, essentially. Much more on glyphosate will be posted in the future as well.

This statement from Head Strong sums up how impactful antibiotics can be:

After all, your mitochondria are evolved from bacteria, and antibiotics are meant to fight bacteria!

Asprey, Dave. Head Strong: The Bulletproof Plan to Activate Untapped Brain Energy to Work Smarter and Think Faster-in Just Two Weeks (Kindle Locations 2573-2575). HarperCollins. Kindle Edition.

Mitochondria are known best for generating ATP, the primary energy currency in the body. The predominant theory of how mitochondria came to be was that they were a separate bacterial organism that got engulfed in eukaryote, or cells that are larger and more complex. They still carry their own DNA, passed on exclusively from the mother, so retain many bacterial properties. So, when we take quinolones, or any antibiotic, the mitochondria may suffer as well. If the mitochondria suffer, so does the whole cell.

So, mitochondria are essentially bacteria inside our cells. The other critical bacteria exist outside our cells in the microbiome, which is more than just our gut. Bacterial cells outnumber human cells in/on the body. Antibiotics quite obviously can impact those as well.

Antibiotics are amazing tools. The art of medicine though is to minimize harm while maximizing benefit. Much harm can be done by antibiotics if not used appropriately,  and part of the appropriateness is knowing when to find alternative options. That is not to say never use them, again they have a very beneficial role to play. If antibiotics are needed, there are some resources available that may help alleviate a portion of the harmful effects. Raise these issues and have a conversation with your provider, especially if a longer term course is being considered.


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