Colchicine is a potent anti-inflammatory alkaloid derived from the autumn crocus (Colchicum autumnale). It is a cornerstone therapy for acute gout flares and Familial Mediterranean Fever (FMF). Its primary mechanism involves binding to tubulin, inhibiting microtubule polymerization, thereby disrupting neutrophil chemotaxis, phagocytosis, and the inflammatory cascade. In the Indian context, it is widely used and available as a low-cost generic medication.
Adult: **Acute Gout:** Initial 1.0-1.2 mg (2 tabs of 0.5mg), followed by 0.5-0.6 mg after 1 hour. **Max 1.8 mg over 1 hour.** Prophylaxis: 0.5-0.6 mg once or twice daily. **FMF:** 1-2 mg daily, may be divided. Max 2.5 mg/day.
Note: Take orally with or without food. For acute gout, initiate at the first sign of a flare. Do not crush or chew. Maintain adequate hydration. Complete the prescribed course; do not take extra tablets for increased pain.
Colchicine binds reversibly to soluble tubulin, forming a colchicine-tubulin complex. This complex binds to the ends of microtubules, preventing their polymerization and elongation. This disrupts the dynamic assembly/disassembly of microtubules, which are critical for cellular functions, particularly in motile cells like neutrophils.
Pregnancy: Category C (US FDA). May cause fetal harm. Use only if potential benefit justifies potential risk to the fetus. Avoid in pregnancy unless for life-threatening FMF. Can affect cell division.
Driving: Generally safe. However, patients experiencing weakness, dizziness, or myopathy as side effects should avoid driving or operating machinery.
| Clarithromycin/Erythromycin | Severe increase in colchicine levels → toxicity (myelosuppression, rhabdomyolysis) | High |
| Cyclosporine | Increased colchicine levels → risk of nephrotoxicity and myotoxicity | High |
| Atorvastatin/Simvastatin | Increased risk of myopathy and rhabdomyolysis | High |
| Digoxin | Potential for increased digoxin levels | Moderate |
| Diltiazem/Verapamil | Moderate increase in colchicine levels | Moderate |
| Fibrates (Gemfibrozil) | Increased risk of myotoxicity | High |
| Strong CYP3A4 inhibitors (Ketoconazole, Ritonavir) | Dramatically increased colchicine levels | High |
| P-glycoprotein inhibitors | Increased colchicine absorption/reduced excretion | High |
Same composition (Colchicine (0.5mg)), different brands: