Most of us have taken antibiotics to treat infections, whether for a nasty bug, a bad scrape, or after surgery. We tend to trust doctors’ recommendations, however, new data about the alarming side effects of a class of antibiotics called fluoroquinolones makes it clear they should only be used as a last resort.
Fluoroquinolones are a class of broad-spectrum antibiotics commonly prescribed for infections of the kidneys, urinary tract, sinuses, and respiratory tract.
Known by names such as Cipro (ciprofloxacin), Cipro XR, Proquin XR, Levaquin (levofloxacin), Floxin, Noroxin, Avelox, Factive, and certain generics, any drug ending in “floxacin” is in this class.
The side effects — sometimes called “getting floxed” — are so severe, the Food and Drug Administration warns to avoid taking this family antibiotics unless there is absolutely no another option.
Fluoroquinolones increase risk of Tendinitis and Tendon Rupture
While fluoroquinolones are known for various side effects, one that may come as a surprise is increased risk of tendinitis and tendon ruptures.
Fluoroquinolones have been shown to weaken and disrupt the underlying structure of tendons. Researchers propose the following causes:
- A boost in levels of enzymes that damage soft tissue.
- Interference with the way our bodies replicate DNA, essential to repair of minor damage that running might cause.
- Disrupted blood flow to collagen in the muscles and tendons.
The Achilles tendon seems to be particularly susceptible, making fluoroquinolones especially problematic for runners.
The average person taking fluoroquinolones has a 70 percent greater risk of tendinopathy and a 30 percent greater risk of full rupture than someone taking a different class of antibiotics.
Signs might include tendon, joint, and muscle pain, sometimes soon after taking the drug. However, the side-effect risks can continue for weeks after you stop taking the drug. The higher your dose and the longer you take fluoroquinolones, the greater your risk of tendon problems.
The most vulnerable populations include:
- Older people
- People with kidney disease
- Patients taking corticosteroid medications
Fluoroquinolones: A long history of side effects
Fluoroquinolones have been required for years to carry warnings to alert doctors and patients of increased risk of certain health issues. As time has revealed the true severity of the effects, the FDA has raised the bar and required them to carry its sternest “black box” warning.
Side effect alerts include:
- In 2008, the FDA added a black box warning to fluoroquinolones regarding the increased risk of tendinitis and tendon rupture.
- In 2011, the risk of worsening symptoms for patients with myasthenia gravis was added to the labeling rule.
- In 2013, the FDA required labeling updates to reflect potential for irreversible peripheral neuropathy (serious nerve damage).
- In 2016, the FDA enhanced warnings on all fluoroquinolones to the “black box” level regarding disabling and potentially permanent side effects involving tendons, muscles, joints, nerves and the central nervous system.
- Because the risk of these side effects generally outweighs potential benefits to patients with acute bacterial sinusitis and uncomplicated urinary tract infections, the FDA determined that these drugs should only be used for as a last resort after other antibiotic classes were tried unsuccessfully.
- As late as July 2018 the FDA announced a labeling change to strengthen warnings about the risks of mental health side effects and severe blood sugar disturbances.
Blood sugar disturbances. Both high and low blood sugar are already included as a warning on most fluoroquinolone labels, however the FDA added that these low blood sugar levels can lead to coma.
Mental health side effects. Across the fluoroquinolone antibiotic class, a range of mental health side effects are already described on the drug labels, including disturbances in attention, disorientation, agitation, nervousness, memory impairment, and delirium. The revised labels will make these side effects more prominent and more consistent across the drug class to better alert doctors and patients.
Fluoroquinolones help create antibiotic resistant bugs
Another reason to avoid this class of drugs is they appear to be especially good at creating antibiotic resistant bugs. The effectiveness of fluoroquinolones at destroying bacteria associated with certain infections has dropped from 100 percent to about 70 percent.
Only use Fluoroquinolones as a last resort
The spread of knowledge about the increased FDA warnings seems to be slow. While medical groups such as the American College of Obstetricians and Gynecologists, the Infectious Diseases Society of America, and the American Thoracic Society have stopped recommending fluoroquinolones as the first line of defense, studies show little reduction so far in the prescription of fluoroquinolones outside of hospitals.
The FDA recommends that whether you are an athlete, if you have a common infection such as bronchitis, sinusitis, or a simple urinary tract infection, don’t agree to take these drugs unless you have no other option.
If your doctor wants to prescribe fluoroquinolones, make sure to tell them about any history of kidney disease, steroid use, or any previous issues with your tendons or muscles. And remember that other serious side effects are possible, including nerve damage, confusion, hallucinations, and blood-sugar related coma.