COLCHICINE

COLCHICINE
(kol'chi-seen)
Novocolchine

Classifications: antigout agent;
Therapeutic:antigout
Pregnancy Category: C

Availability

0.5 mg, 0.6 mg tablets

Action

Alkaloid of the plant Colchicum with antimitotic and indirect antiinflammatory properties. Colchicine inhibits the migration of neutrophils into the area of inflammation. Although it does not inhibit phagocytosis of uric acid crystals, it does appear to prevent the release of an inflammatory glycoprotein from phagocytes in the inflammatory process.

Therapeutic Effect

Inhibition of inflammation and reduction of pain and swelling, which occurs in gouty arthritis. Colchicine is nonanalgesic and nonuricosuric.

Uses

Prophylactically for recurrent gouty arthritis and for acute gout, either as single agent or in combination with a uricosuric such as probenecid, allopurinol, or sulfinpyrazone.

Unlabeled Uses

Sarcoid arthritis, chondrocalcinosis (pseudogout), arthritis associated with erythema nodosum, leukemia, adenocarcinoma, acute calcific tendonitis, familial Mediterranean fever, multiple sclerosis, primary biliary cirrhosis, mycosis fungoides, and in experimental studies of normal and abnormal cell division.

Contraindications

Blood dyscrasias; severe GI, renal, hepatic, or cardiac disease; pregnancy (category C). Safe use in children not established.

Cautious Use

Older adult and debilitated patients, early manifestations of GI, renal, hepatic, or cardiac disease.

Route & Dosage

Acute Gouty Attack
Adult: PO 0.5–1.2 mg followed by 0.5–0.6 mg q1–2h until pain relief or intolerable GI symptoms (max: 4 mg/attack)

Prophylaxis
Adult: PO 0.5 or 0.6 mg every night or every other night as needed (up to 1.8 mg/d may be needed for severe cases)

Surgical Patients
Adult: PO 0.5 or 0.6 mg t.i.d. starting 3 d before surgery and continuing for 3 d after surgery

Renal Impairment
Cl_cr 10–50 mL/min: prolonged use is not recommended; <10 mL/min: reduce recommended dose by 50%

Administration

Oral

Administer oral drug with milk or food to reduce possibility of GI upset.

Preserve in tight, light-resistant containers preferably between 15°–30° C (59°–86° F), unless otherwise directed by manufacturer.

Adverse Effects (≥1%)

GI: Nausea, vomiting, diarrhea, abdominal pain, anorexia, hemorrhagic gastroenteritis, steatorrhea, hepatotoxicity, pancreatitis. Hematologic: Neutropenia, bone marrow depression, thrombocytopenia, agranulocytosis, aplastic anemia. CNS: Mental confusion, peripheral neuritis, syndrome of muscle weakness (accompanied by elevated serum creatine kinase). Skin: Severe irritation and tissue damage if IV administration leaks around injection site. Urogenital: Azotemia, proteinuria, hematuria, oliguria.

Diagnostic Test Interference

Possible interference with urinary steroid (17-OHCS) determinations when done by modifications of Reddy, Jenkins, Thorn procedure. False-positive urine tests for RBCs and Hgb reported.

Interactions

Drug: May decrease intestinal absorption of vitamin B₁₂.

Pharmacokinetics

Absorption: Rapidly from GI tract. Peak: 0.5–2 h; may have multiple peaks because of enterohepatic cycling. Distribution: Widely distributed; concentrates in leukocytes, kidney, liver, spleen, and intestinal tract. Metabolism: Partially metabolized in liver. Elimination: Primarily in feces; 10–20% in urine in 24 h.

Nursing Implications

Assessment & Drug Effects

Lab tests: Baseline and periodic determinations of serum uric acid and creatinine are advised, as well as CBC, including Hgb, platelet count, serum electrolytes, and urinalysis.
Monitor for dose-related adverse effects; they are most likely to occur during the initial course of treatment.
Monitor for early signs of colchicine toxicity including weakness, abdominal discomfort, anorexia, nausea, vomiting, and diarrhea, regardless of administration route. Report to physician. To avoid more serious toxicity, drug should be discontinued promptly until symptoms subside.
Monitor I&O ratio and pattern (during acute gouty attack): High fluid intake promotes excretion and reduces danger of crystal formation in kidneys and ureters.
Keep physician informed of patient's progress. Drug should be stopped when pain of acute gout is relieved. Therapeutic response: articular pain and swelling generally subside within 8–12 h and usually disappear in 24–72 h after PO therapy, and 6–12 h after IV administration.

Patient & Family Education

If taking colchicine at home, withhold drug and report to the physician the onset of GI symptoms or signs of bone marrow depression (nausea, sore throat, bleeding gums, sore mouth, fever, fatigue, malaise, unusual bleeding or bruising).
Keep colchicine on hand at all times to start therapy or increase dosage, as prescribed by physician, at the first suggestion of an acute attack.
Physician may prescribe sodium bicarbonate, or sodium or potassium citrate, to maintain alkaline urine and thus prevent formation of urate stones.
Avoid fermented beverages such as beer, ale, and wine as they may precipitate gouty attack. The physician may allow distilled alcoholic beverages in moderation.

Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; Canadian drug name; Prototype drug

(415)