Kolchicyna

Kolchicyna, or colchicine, is a natural alkaloid derived from Colchicum autumnale and related species. It is a prescription medication with a narrow therapeutic window and is highly toxic in larger amounts.

Mechanism of action and effects: Colchicine binds to tubulin, inhibiting microtubule polymerization. This disrupts mitosis and reduces neutrophil chemotaxis and inflammatory mediator release, providing anti-inflammatory effects in certain conditions. The drug does not relieve pain by acting on uric acid directly but modulates inflammatory processes.

Medical uses: Colchicine is used for the treatment of acute gout flares and, at lower, ongoing doses, for gout prophylaxis. It is a standard therapy to prevent amyloidosis and Attenuate attacks in familial Mediterranean fever (FMF). It is also used in some cases of recurrent pericarditis. Dosing and duration depend on the condition, patient factors, and potential drug interactions, and therapy should be overseen by a clinician.

Pharmacokinetics and administration: Colchicine is administered orally and is distributed widely in body tissues. It is metabolized mainly by hepatic enzymes including CYP3A4 and is transported by P-glycoprotein; excretion occurs in urine and feces. The drug has a narrow therapeutic index and exhibits variable pharmacokinetics, especially in renal or hepatic impairment.

Safety, adverse effects, and interactions: Common adverse effects include gastrointestinal symptoms such as nausea, vomiting, and diarrhea. Serious toxicity can involve bone marrow suppression, hepatotoxicity, neuromuscular effects, and multiorgan failure, particularly in patients with kidney or liver disease or with drug interactions. Interactions with strong CYP3A4 inhibitors or P-glycoprotein inhibitors (for example certain macrolide antibiotics, azole antifungals, and some calcium channel blockers) can markedly increase toxicity. Use in pregnancy and lactation is generally approached with caution.

Overdose and management: There is no specific antidote. Management involves rapid assessment, activated charcoal if early after ingestion, and supportive care in a hospital setting for severe cases.