Major
Ciprofloxacin × Prednisolone
Fluoroquinolone antibacterials×Glucocorticoids
Mechanism
Additive tendon injury risk. Fluoroquinolones disrupt collagen synthesis in tendon fibres; glucocorticoids suppress repair. FDA carries a boxed warning for tendinitis and Achilles tendon rupture.
Symptoms
Pain and swelling in the Achilles tendon (less often other large tendons). Sudden 'snap' and inability to bear weight indicates rupture. Symptoms typically appear within 1–4 weeks.
Management
Avoid the combination, especially in patients over 60 and athletes. Alternative antibiotics: a cephalosporin or nitrofurantoin (no tendon effect). If ciprofloxacin is needed, limit physical activity for the whole course and 1 month after.
Check the full regimen, not just this pair
Opens the checker with these two drugs prefilled. Add the rest of the regimen and recompute additive risks.