Overview
Colchicine is an anti-inflammatory medication primarily used for prophylaxis of gout flares in adults. It works by inhibiting microtubule polymerization and neutrophil migration, reducing inflammation associated with gout attacks. The drug requires careful dosing due to narrow therapeutic index and potential for serious toxicity, particularly with drug interactions.
Mechanism of Action
Colchicine binds to tubulin, inhibiting microtubule polymerization and disrupting cytoskeletal functions. This prevents neutrophil migration, degranulation, and phagocytosis, reducing the inflammatory response in gout. It also inhibits the formation of amyloid fibrils and interferes with cell division.
Indications
- Prophylaxis of gout flares in adults
Common Doses
- 0.6 mg capsules
Dosage
For gout prophylaxis: 0.6 mg once or twice daily. Maximum dose 1.2 mg/day. Dose adjustment required for renal impairment, hepatic impairment, elderly patients, and with concomitant medications that affect CYP3A4 or P-glycoprotein.
Contraindications
- Patients with both renal and hepatic impairment
- Patients with renal or hepatic impairment taking dual inhibitors of P-glycoprotein and CYP3A4
Side Effects
- Diarrhea
- Nausea
- Vomiting
- Abdominal pain
- Muscle pain or weakness
- Myelosuppression (leukopenia, granulocytopenia, thrombocytopenia)
- Elevated liver enzymes (AST, ALT)
- Rhabdomyolysis
- Alopecia
- Rash
- Neuropathy
- Azoospermia/oligospermia
Interactions
- Clarithromycin (dual CYP3A4/P-glycoprotein inhibitor) - fatal interactions reported
- Other CYP3A4 inhibitors: erythromycin, verapamil, grapefruit juice
- P-glycoprotein inhibitors: cyclosporine
- Concomitant use with dual inhibitors contraindicated in renal/hepatic impairment
Counseling Points
- Take as prescribed; do not exceed recommended dose
- Report severe diarrhea, nausea, vomiting, or abdominal pain immediately
- Inform healthcare provider of all medications, including OTC drugs and supplements
- Avoid grapefruit juice while taking colchicine
- Report muscle pain, weakness, or unusual bleeding/bruising
- Use effective contraception if of reproductive potential