NABUMETONE (Relafen): What is used for?

What is Nabumetone?

Nabumetone is an active ingredient used for the treatment of watery rheumatoid arthritis, acute osteoarthritis and acute periarticular pain.

The brand names of Nabumetone in United States are: Relafen, Relafen DS.

Nabumetone Mechanism of Action (MOA)

Inhibits the synthesis of prostaglandins (via cyclooxygenase-2 inhibition) in synovial tissue and fluid and in other inflammatory exudates, free radical activity at the site of inflammation, production of arachidonic acid metabolites and leucocyte activity.

Therapeutic indications, uses and benefits of Nabumetone

  • Acute and chronic osteoarthritis.
  • Chronic and acute rheumatoid arthritis.
  • Acute periarticular ailments.

Dosage of Nabumetone

Oral Nabumetone (500 mg, 750 mg)

Adults: 1 g/day, (single dose).
Increase to 1,500 mg or 2 g/day (single or fractional dose).

Method of administration of Nabumetone

Oral use.
Take with or without food.

Contraindications of Nabumetone

  • Hypersensitivity to nabumetone.
  • History of gastrointestinal bleeding or perforation related to previous NSAID treatments.
  • Active or recurrent peptic ulcer/gastrointestinal bleeding (2 or more episodes).
  • Severe heart failure.
  • Third trimester of gestation.

Warnings and precautions with Nabumetone

  • Severe kidney and/or liver failure.
  • History of asthma induced by ASA or other NSAIDs, hives, and other allergic reactions.
  • History of ulcer, hemorrhage, or gastrointestinal perforation, increased risk at high doses, and prolonged treatment.
  • High blood pressure and/or heart failure.
  • Concomitant use with oral anticoagulants (dicumarinics).
  • Platelet antiaggregants of type AAS.
  • Oral corticoids and antidepressants selective inhibitors of serotonin reuptake.
  • Evaluate treatment in: Hypertension, CHF, established coronary artery disease, peripheral artery disease and/or uncontrolled cerebrovascular disease, also assess patients with known cardiovascular risk factors (hypertension, hyperlipidemia, diabetes mellitus, smokers) before starting long-term treatment.)
  • May exacerbate Crohn’s disease or a history of ulcerative colitis.
  • Analytical, hepatic and renal control.
  • Avoid concomitant use with other NSAIDs, including selective cyclo-oxygenase-2 inhibitors.
  • Not recommended for children. May alter female fertility.
  • Risk of severe skin reactions, including exfoliative dermatitis, Stevens-Johnson syndrome, toxic epidermal necrolysis and drug reaction with eosinophilia and systemic symptoms, discontinue treatment at the first symptoms of erythema cutaneous, mucosal lesions or other signs of hypersensitivity.

Liver failure

Severe liver failure.

Kidney failure

Severe renal failure.

Interactions with Nabumetone

  • Increases the risk of gastrointestinal bleeding or ulcer with: dicumarinic oral anticoagulants, acetylsalicylic acid type platelet antiaggregants, oral corticoids, selective serotonin reuptake inhibitors (SSRIs) antidepressants.
  • Avoid concomitant administration with other NSAIDs, including selective cyclo-oxygenase-2 inhibitors.
  • Possible reduction of the antihypertensive effect of: antihypertensive, including diuretics.
  • Possible increase in toxicity of: lithium, methotrexate.

Pregnancy and Nabumetone

Not recommended in the first and second trimester of pregnancy unless absolutely necessary.
Contraindicated third trimester of pregnancy, may expose the fetus to cardio-pulmonary toxicity, renal dysfunction, possible prolongation of bleeding time, inhibition of uterine concentrations.


In general, all NSAIDs can induce delayed delivery, exert an action on the fetal cardiovascular system, and pass into breast milk.
Postnatal development was not affected, even though the active metabolite of nabumetone (6MNA) is detected in the milk of lactating rats.
Due to lack of human experience, its use should be restricted to those cases where the potential benefit to mothers justifies the potential risk to the infant.

Effects on driving ability

There is a risk of vertigo or other central nervous system disorders following administration of nabumetone. In such cases, the patient should not drive or use machinery.

Adverse reactions and side effects of Nabumetone

Nausea, diarrhoea, vomiting, epigastric pain.

Transit disorders, ulcers, perforations, haemorrhagic colitis.

Digestive ulcerations with or without haemorrhage, occult or visible haemorrhage and anorexia.


Source: The content of this active ingredient has been written taking into account the clinical and molecular information of all medicines authorised and marketed in the United States under the Unique Ingredient Identifier (UNII) by the Substance Registration System (SRS) of the Food and Drug Administration (FDA) and the United States Pharmacopeia (USP).

In order to know in detail the information authorized by the FDA for each drug, you should consult the corresponding medication guide authorized by the FDA.


PubChem CID: 4409
NCI Thesaurus: C47627


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