Tendon rupture due to antibiotics?!

[Canadjun]

I have a question for the medically knowledgable here, but it is a question about mechanism, not asking for medical advice, so I think GQ is still OK for it.

I sometimes take Cipro or Levaquin for bladder infections (I get serious ones A LOT because of my disability), and the info about those drugs on the web puzzles me.

HOW do they (or any other drug) have a propensity to sometimes cause tendon rupture as a side effect?? Or, to phrase it differently, how is it possible to rot through a tendon with any drugs? I thought they basically just attached your muscles to your bones. I know you can get tendonitis from overexercising so obviously they are living tissue, but I am really puzzled what is going on when a drug causes tendon rupture.

[Qadgop_the_Mercotan]

Here’s the current mainstream medical thinking, quick and dirty, from UpToDate.com, a subscription medical website.

Fluoroquinolone antibiotics are rarely associated with tendinopathy. The incidence of rupture is estimated at 12 per 100,000 treatment episodes (OR 1.3; 95% CI 1.0-1.8). The mechanism is unknown. A study of 46,776 patients treated with fluoroquinolones found 3.2 cases of tendon problems for every 1000 years of exposure. Past use does not confer future risk. Concurrent use of fluoroquinolones and systemic steroids further increases risk.

So the risk is pretty damn low, and past use doesn’t mean increased risk of future problems.

But hopefully you won’t need to take steroids while on the quinolones.

[Canadjun]

Thanks. QtM. Strange…

(touch wood, I’ve never needed steroids and hope not to ever need to)