Ciprofloxacin × Methylprednisolone

Fluoroquinolones, including ciprofloxacin, can cause tendinitis and tendon rupture, most often of the Achilles tendon. The risk is higher in older patients, in renal impairment, after solid organ transplantation and in patients who take corticosteroids at the same time (ciprofloxacin SmPC). Methylprednisolone itself very rarely causes tendon rupture, for example of the Achilles tendon (methylprednisolone SmPC). The US Food and Drug Administration (FDA) label specifies age over 60 and adds strenuous physical activity and previous tendon disorders as risk factors (ciprofloxacin FDA label). A second mechanism is metabolic: some corticosteroids are cleared by the CYP3A4 enzyme (methylprednisolone SmPC), and the FDA classes ciprofloxacin as a moderate CYP3A inhibitor (FDA list), so methylprednisolone levels may rise.

Pain, swelling and inflammation of the Achilles tendon, less often of tendons in the shoulder, hand or biceps, sometimes on both sides, up to tendon rupture (ciprofloxacin labels). Symptoms can start within 48 hours of starting ciprofloxacin and as late as several months after the course ends (ciprofloxacin SmPC).

The ciprofloxacin SmPC says concomitant use of corticosteroids should be avoided because of the risk of tendinitis and tendon rupture (ciprofloxacin SmPC). The methylprednisolone SmPC also advises avoiding CYP3A inhibitors unless the benefit outweighs the higher risk of systemic corticosteroid adverse effects, and monitoring the patient for them if the combination is used (methylprednisolone SmPC); the US Food and Drug Administration (FDA) classes ciprofloxacin as a moderate CYP3A inhibitor (FDA list). Ciprofloxacin is generally not given to patients who have had tendon disorders with a quinolone before (ciprofloxacin SmPC). Warn the patient about the symptoms: at the first sign of tendinitis, such as painful swelling or inflammation, stop ciprofloxacin at once and immobilise the affected limb, and do not use corticosteroids if there are signs of tendinopathy (ciprofloxacin SmPC).