Leflunomide
Leflunomide (Arava)
Leflunomide
(leh- FLOON-oh-myd)
Pregnancy Category: X Arava (Rx)

Classification: Anti-arthritic drug

Action/Kinetics: Inhibits dihydroorotate dehydrogenase, an enzyme involved in de novo pyrimidine synthesis; has antiproliferative activity and an anti-inflammatory effect. After PO, is metabolized to an active metabolite (M1). Peak levels, M1: 6-12 hr. t 1/2, M1: About 2 weeks. M1 is extensively bound to albumin. M1 is further metabolized and excreted through the kidney (more significant over the first 96 hr) and bile.

Uses: Treatment of active rheumatoid arthritis in adults, including to retard structural damage.

Contraindications: Use in pregnancy, lactation, in children less than 18 years of age, in hepatic insufficiency, or positive hepatitis B or C. Also, use in those with severe immunodeficiency, bone marrow dysplasia, severe uncontrolled infections, or vaccination with live vaccines.

Special Concerns: Use with caution in those with renal insufficiency.

Side Effects: GI: Diarrhea, N&V;, dyspepsia, abnormal liver enzymes, GI/abdominal pain, anorexia, dry mouth, gastroenteritis, mouth ulcer, cholelithiasis, colitis, constipation, esophagitis, flatulence, gastritis, gingivitis, melena, oral moniliasis, pharyngitis, enlarged salivary gland, stomatitis or aphthous stomatitis, tooth disorder. CNS: Headache, dizziness, paresthesia, anxiety, depression, insomnia, neuralgia, neuritis, sleep disorder, sweat, vertigo. CV: Hypertension (as pre-existing condition was over represented in drug treatment groups), chest pain, angina pectoris, migraine, palpitation, tachycardia, vasculitis, vasodilation, varicose vein. Dermatologic: Alopecia, rash, pruritus, eczema, dry skin, acne, contact dermatitis, fungal dermatitis, hair discoloration, hematoma, herpes simplex, herpes zoster, nail disorder, skin nodule, subcutaneous nodule, maculopapular rash, skin disorder, skin discoloration, skin ulcer. Musculoskeletal: Joint disorder, tenosynovitis, synovitis, arthralgia, leg cramps, arthrosis, bursitis, muscle cramps, myalgia, bone necrosis, bone pain, tendon rupture. Respiratory: Respiratory infection, bronchitis, increased cough, pharyngitis, pneumonia, rhinitis, sinusitis, asthma, dyspnea, epistaxis, lung disorder. GU: Albuminuria, cystitis, dysuria, hematuria, menstrual disorder, vaginal moniliasis, prostate disorder, urinary frequency, UTI. Hematologic: Anemia, including iron deficiency anemia; ecchymosis. Metabolic: Weight loss, hypokalemia, peripheral edema, hyperglycemia, hyperlipidemia. Ophthalmic: Blurred vision, cataract, conjunctivitis, eye disorder. Miscellaneous: Diabetes mellitus, hyperthyroidism, taste perversion, back pain, injury accident, infection, asthenia, allergic reaction, flu syndrome, pain, abscess, cyst, fever, hernia, malaise, neck pain, pelvic pain.

Laboratory Test Alterations: ALT, AST, creatine phosphokinase. Uricosuric effect, hypophosphatemia.

Overdose Management: Symptoms: See Side Effects. Treatment: Give cholestyramine or charcoal. Dose of cholestyramine is 8 g t.i.d. PO for 24 hr. Dose of charcoal is 50 g made into a suspension for PO or NGT given q 6 hr for 24 hr.

Drug Interactions: Charcoal / Rapid/significant in leflunomide active M1 metabolite Cholestyramine / Rapid/significant in leflunomide active M1 metabolite Hepatotoxic drugs / Side effects Rifampin / M1 peak levels

How Supplied: Tablets: 10 mg, 20 mg, 100 mg

Dosage
?Tablets Rheumatoid arthritis.
Loading dose: 100 mg/day PO for 3 days. Maintenance: 20 mg/day; if this dose is not well tolerated, decrease to 10 mg/day. Doses greater than 20 mg/day are not recommended due to increased risk of side effects.