Nabumetone

Drug Interactions: ACE-inhibitors: Reports suggest that NSAIDs may diminish the antihypertensive effect of ACE-inhibitors. This interaction should be given consideration in patients taking NSAIDs concomitantly with ACE-inhibitors. Aspirin: When nabumetone tablets are administered with aspirin, its protein binding is reduced, although the clearance of free nabumetone is not altered. The clinical significance of this interaction is not known; however, as with other NSAIDs, concomitant administration of nabumetone tablets and aspirin is not generally recommended because of the potential of increased adverse effects. Diuretics: Clinical studies, as well as post marketing observations, have shown that nabumetone can reduce the natriuretic effect of furosemide and thiazides in some patients. This response has been attributed to inhibition of renal prostaglandin synthesis. During concomitant therapy with NSAIDs, the patient should be observed closely for signs of renal failure (see WARNINGS , Renal Effects ), as well as to assure diuretic efficacy. Lithium: NSAIDs have produced an elevation of plasma lithium levels and a reduction in renal lithium clearance. The mean minimum lithium concentration increased 15% and the renal clearance was decreased by approximately 20%. These effects have been attributed to inhibition of renal prostaglandin synthesis by the NSAID. Thus, when NSAIDs and lithium are administered concurrently, subjects should be observed carefully for signs of lithium toxicity. Methotrexate: NSAIDs have been reported to competitively inhibit methotrexate accumulation in rabbit kidney slices. This may indicate that they could enhance the toxicity of methotrexate. Caution should be used when NSAIDs are administered concomitantly with methotrexate. Warfarin: The effects of warfarin and NSAIDs on GI bleeding are synergistic, such that users of both drugs together have a risk of serious GI bleeding higher than users of either drug alone. In vitro studies have shown that, because of its affinity for protein, 6MNA may displace other protein-bound drugs from their binding site. Caution should be exercised when administering nabumetone with warfarin since interactions have been seen with other NSAIDs. Concomitant administration of an aluminum-containing antacid had no significant effect on the bioavailability of 6MNA. When administered with food or milk, there is more rapid absorption; however, the total amount of 6MNA in the plasma is unchanged (see CLINICAL PHARMACOLOGY , Pharmacokinetics ).

Nabumetone tablets, USP are indicated for relief of signs and symptoms of osteoarthritis and rheumatoid arthritis." Use is recommended at "the lowest effective dose for the shortest duration consistent with individual patient treatment goals.

DOSAGE AND ADMINISTRATION Carefully consider the potential benefits and risks of nabumetone tablets and other treatment options before deciding to use nabumetone tablets. Use the lowest effective dose for the shortest duration consistent with individual patient treatment goals (see WARNINGS ). After observing the response to initial therapy with nabumetone tablets, the dose and frequency should be adjusted to suit an individual patient’s needs. Osteoarthritis and Rheumatoid Arthritis: The recommended starting dose is 1,000 mg taken as a single dose with or without food. Some patients may obtain more symptomatic relief from 1,500 mg to 2,000 mg per day. Nabumetone can be given in either a single or twice-daily dose. Dosages greater than 2,000 mg per day have not been studied. The lowest effective dose should be used for chronic treatment (see WARNINGS , Renal Effects ). Patients weighing under 50 kg may be less likely to require dosages beyond 1,000 mg; therefore, after observing the response to initial therapy, the dose should be adjusted to meet individual patients’ requirements.

Most common reactions involve the GI tract: "diarrhea (14%), dyspepsia (13%), abdominal pain (12%)." Additional effects include headache, dizziness, and rash. Less common but serious reactions include GI bleeding, Stevens-Johnson syndrome, and anaphylactoid reactions.