• PO (Adults): Treatment of acute attacks — 0.6–1.2 mg, then 0.6 mg q 1–2 hr or 1–1.2 mg q 2 hr until relief, GI side effects, or a total cumulative dose of 8 mg is achieved. Prophylaxis — 0.6 mg daily (may be used up to 3 times daily or as little as 1–4 times weekly). If surgery is planned, give 3 times daily for 3 days before and 3 days after procedure.
• IV (Adults): Treatment of acute attack — 2 mg initially, then 0.5 mg q 6 hr or 1 mg q 6–12 hr, until relief or cumulative dose of 4 mg has been given. Other regimens may use lower doses. Prophylaxis — 0.5–1 mg 1–2 times daily. Other regimens may use lower doses.
The exact mechanism of action of colchicine in gout is not completely known, but it involves a reduction in lactic acid production by leukocytes, which results in a decrease in uric acid deposition, and a reduction in phagocytosis, with abatement of the inflammatory response.
In familial Mediterranean fever, colchicine may interfere with the intracellular assembly of the inflammasome complex present in neutrophils and monocytes that mediates activation of interleukin-1beta.
Colchicine disrupts cytoskeletal functions through inhibition of beta-tubulin polymerization into microtubules, and consequently prevents the activation, degranulation, and migration of neutrophils.
Serious GI, renal, hepatic, or cardiac disorders; blood dyscrasias; coadministration with P-glycoprotein (Pgp) or strong CYP3A4 inhibitors in patients with renal or hepatic impairment ( Colcrys only); hypersensitivity to the drug.
Use Cautiously in:
Elderly or debilitated patients (toxicity may be cumulative).
Renal impairment (dose reduction suggested if CCr <50 ml/min; total IV dose not >2 mg) .
The risk of myopathy or rhabdomyolysis may be increased. If coadministration cannot be avoided, monitor the patient for signs of any unexplained muscle pain, tenderness, or weakness. If colchicine toxicity is suspected, discontinue colchicine.
Colchicine plasma concentrations may be elevated by grapefruit juice ingestion, increasing the risk of toxicity (eg, myopathy). Advise patients taking colchicine not to consume grapefruit juice.
Colchicine plasma concentrations may be elevated, increasing the risk of toxicity (eg, myopathy). Coadminister with caution, starting at reduced colchicine doses, and increase monitoring of creatine phosphokinase and for adverse reactions. If colchicine toxicity is suspected, discontinue colchicine.
Life-threatening and fatal drug interactions have been reported in patients receiving colchicine and Pgp inhibitors or strong CYP3A4 inhibitors. Coadministration of colchicine and a Pgp inhibitor or strong CYP3A4 inhibitor to patients with renal or hepatic impairment is contraindicated. If treatment with a Pgp inhibitor or strong CYP3A4 inhibitor is needed in patients with healthy renal and hepatic function, the colchicine dose may need to be reduced or withheld. If colchicine toxicity is suspected, discontinue colchicine.
The action of sympathomimetics may be increased. Monitor the patient and adjust the sympathomimetic dose as needed.