NABUMETONE
| NABUMETONE (na-bu-me'tone) Relafen Classifications: analgesic, nonsteroidal antiinflammatory drug (nsaid); antipyretic; Therapeutic: nsaid, analgesic; antipyretic Prototype: Ibuprofen Pregnancy Category: C |
Availability
500 mg, 750 mg tablets
Action
Blocks prostaglandin synthesis by inhibiting cyclooxygenase, an enzyme that converts arachidonic acid to precursors of prostaglandins.
Therapeutic Effect
Antiinflammatory, analgesic, and antipyretic effects. Inhibits platelet aggregation and prolongs bleeding time but does not affect prothrombin or whole blood clotting times.
Uses
Rheumatoid arthritis and osteoarthritis.
Contraindications
Patients in whom urticaria, severe rhinitis, bronchospasm, angioedema, or nasal polyps are precipitated by aspirin or other NSAIDs; salicylate hypersensitivity; active peptic ulcer; bleeding abnormalities; CABG perioperative pain; pregnancy (category C), lactation. Safe use in children <6 mo is not established.
Cautious Use
Hypertension, history of GI ulceration, impaired liver or kidney function, chronic kidney failure, cardiac decompensation, bone marrow suppression; patients with SLE.
Route & Dosage
| Rheumatoid & Osteoarthritis Adult: PO 1000 mg/d as a single dose, may increase (max: of 2000 mg/d in 1–2 divided doses) |
Administration
Oral- Give with food, milk, or antacid (if prescribed) to reduce the possibility of GI upset.
- Store at 15°–30° C (59°–86° F).
Adverse Effects (≥1%)
GI: Diarrhea, abdominal pain, nausea, dyspepsia, flatulence, melena, ulcers, constipation, dry mouth, gastritis. CNS: Tinnitus, dizziness, headache, insomnia, vertigo, fatigue, diaphoresis, nervousness, somnolence. Skin: Rash, pruritus.Interactions
Drug: May attenuate the antihypertensive response to diuretics. nsaids increase the risk of methotrexate toxicity. Food: Food may increase the peak but not the overall absorption of nabumetone. Herbal: Feverfew, garlic, ginger, ginkgo may increase bleeding potential.Pharmacokinetics
Absorption: Readily absorbed from GI tract; approximately 35% is converted to its active metabolite on first pass through the liver. Onset: 1–3 wk for antirheumatic action. Peak: 3–6 h. Distribution: 99% protein bound; distributes into synovial fluid. Metabolism: In liver to its active metabolite, 6-methoxy-2-naphthylacetic acid (6MNA). Elimination: 80% of dose is excreted in urine as 6MNA; 10% excreted in feces. Half-Life: 24 h (6MNA).Nursing Implications
Assessment & Drug Effects
- Lab tests: Obtain baseline and periodic evaluation of Hgb and Hct levels with prolonged or high-dose therapy.
- Monitor for signs and symptoms of GI bleeding.
Patient & Family Education
- Use caution with hazardous activities since nabumetone may cause dizziness, drowsiness, and blurred vision.
- Report abdominal pain, nausea, dyspepsia, or black tarry stools.
- Be aware that alcohol and aspirin will increase the risk of GI ulceration and bleeding.
- Notify your physician if any of the following occur: persistent headache, skin rash or itching, visual disturbances, weight gain, or edema.
Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; 
Canadian drug name; 
Prototype drug