Moderate
Ciprofloxacin × Colchicine
Fluoroquinolone antibacterials×Antigout agents
Mechanism
Ciprofloxacin is a weak P-glycoprotein inhibitor and may slightly raise colchicine levels. Clinically significant colchicine toxicity is rare, mainly in chronic kidney disease.
Symptoms
Nausea, vomiting, diarrhoea, muscle weakness, paraesthesias. With severe toxicity: myopathy, neuropathy, bone marrow suppression.
Management
For short ciprofloxacin courses (5–7 days) with normal renal function, no colchicine adjustment needed. With creatinine clearance below 50 mL/min, halve the colchicine dose or pause it. In gout patients needing an antibiotic, alternative: a cephalosporin (no P-glycoprotein effect).