Colchicine × Etoricoxib

In a gout flare both are used, but along routes whose adverse effects overlap: colchicine damages intestinal mucosa while etoricoxib inhibits COX-2 with renal and blood pressure impact. The colchicine label warns that macrolides, CYP3A4 inhibitors, ciclosporin, protease inhibitors, calcium antagonists and statins raise its levels and can cause toxicity; etoricoxib is not on that list, so the risk here is additive rather than metabolic.

Diarrhoea, nausea and abdominal pain come first and are the classic warning of excess colchicine. Etoricoxib adds oedema, rising blood pressure and reduced urine output. Muscle weakness with dark urine points to colchicine myopathy, especially with statins or low renal filtration.

In a flare use the short low-dose colchicine regimen and keep etoricoxib as brief as possible, watching blood pressure and oedema. Diarrhoea marks the colchicine ceiling: once it appears, reduce or stop. With low renal filtration or statins, review the colchicine dose before starting.