Colchicine × Spironolactone

Spironolactone is a weak P-glycoprotein inhibitor and may slightly raise colchicine levels. Clinically significant toxicity is described in chronic kidney disease and on long-term combination.

Nausea, vomiting, diarrhoea, muscle weakness, paraesthesias. With severe toxicity: myopathy, neuropathy, bone marrow suppression.

With normal renal function, no dose adjustment needed. With creatinine clearance below 50 mL/min, halve the colchicine dose. Check creatinine, CK, and CBC every 3 months. In gout flares, a short colchicine course (0.5 mg 2–3 times daily for 1–3 days) is better tolerated than long-term use.