A story built from the name colchicine itself - so the mechanism of action, key side effects, and the way Step 1 actually tests it stick on the first read.
▶ Watch the breakdown

A 62-year-old man develops an acutely swollen, red, painful big toe and is started on colchicine. Two days later, he has severe diarrhea and muscle weakness, with an elevated creatine kinase. His chart shows he was recently started on clarithromycin. What best explains his new symptoms?
More Antigout
Colchicine is a microtubule inhibitor used for acute gout flares and long-term prophylaxis, including familial Mediterranean fever. It binds tubulin and blocks neutrophil migration to the inflamed joint but does not lower uric acid levels. Toxicity is narrow — renal impairment and CYP3A4/P-glycoprotein inhibitors like clarithromycin both raise drug levels, causing the classic triad of GI distress, myelosuppression, and neuromyopathy.
Every Monday, one new drug. Story, mnemonic, and practice question. Completely free.