CriticalAntigout agents×HIV protease inhibitor / pharmacokinetic booster
Updated · Methodology
Mechanism
Colchicine is a CYP3A4 and P-glycoprotein substrate with narrow therapeutic window. Ritonavir is the strongest CYP3A4 inhibitor and a notable P-glycoprotein inhibitor. Colchicine levels rise 4-fold or more. FDA carries a boxed warning.
Symptoms
Profuse diarrhoea, vomiting, abdominal pain – first signs of toxicity. Pancytopenia (drop in leukocytes, erythrocytes, platelets), muscle weakness, peripheral neuropathy, hepatic and renal injury follow. Fatal cases have been reported.
Management
The combination is not prescribed. For acute gout in a patient on ritonavir, use glucocorticoids (intra-articular or short systemic) or NSAIDs. For long-term prophylaxis, allopurinol.
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.
Summary of a multi-drug list →
Medicine list: everything you take in one place →
Sources
- FDA: Colchicine tablet (Par Health USA, LLC) – Prescribing Information (2009)– ; DailyMed setid 72984aa2-6df9-4460-9926-399ffed30e36
- AEMPS: Ficha técnica: Ritonavir (nº registro 81039), sección 4.3 (2025)– AEMPS, CIMA, nº registro 81039, revisión 04/2025, sección 4.3