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Class: Other Nonsteroidal Anti-inflammatory Agents
Chemical Name: 4-(6-Methoxy-2-naphthyl)-2-butanone
Molecular Formula: C15H16O2
CAS Number: 42924-53-8


Special Alerts:

[Posted 07/09/2015]

AUDIENCE: Health Professional, Consumer

ISSUE: FDA is strengthening an existing label warning that non-aspirin nonsteroidal anti-inflammatory drugs (NSAIDs) increase the chance of a heart attack or stroke. Based on FDAs comprehensive review of new safety information, FDA is requiring updates to the drug labels of all prescription NSAIDs. As is the case with current prescription NSAID labels, the Drug Facts labels of over-the-counter (OTC) non-aspirin NSAIDs already contain information on heart attack and stroke risk. FDA will also request updates to the OTC non-aspirin NSAID Drug Facts labels. See the FDA Drug Safety Communication (Table 1) at: for a list of non-aspirin nonsteroidal anti-inflammatory drug products.

Prescription NSAID labels will be revised to reflect the following information:

  • The risk of heart attack or stroke can occur as early as the first weeks of using an NSAID. The risk may increase with longer use of the NSAID.

  • The risk appears greater at higher doses.

  • It was previously thought that all NSAIDs may have a similar risk. Newer information makes it less clear that the risk for heart attack or stroke is similar for all NSAIDs; however, this newer information is not sufficient for us to determine that the risk of any particular NSAID is definitely higher or lower than that of any other particular NSAID.

  • NSAIDs can increase the risk of heart attack or stroke in patients with or without heart disease or risk factors for heart disease. A large number of studies support this finding, with varying estimates of how much the risk is increased, depending on the drugs and the doses studied.

  • In general, patients with heart disease or risk factors for it have a greater likelihood of heart attack or stroke following NSAID use than patients without these risk factors because they have a higher risk at baseline.

  • Patients treated with NSAIDs following a first heart attack were more likely to die in the first year after the heart attack compared to patients who were not treated with NSAIDs after their first heart attack.

  • There is an increased risk of heart failure with NSAID use.

BACKGROUND: The risk of heart attack and stroke with NSAIDs, either of which can lead to death, was first described in 2005 in the Boxed Warning and Warnings and Precautions sections of the prescription drug labels. Since then, FDA reviewed a variety of new safety information on prescription and OTC NSAIDs, including observational studies, a large combined analysis of clinical trials, and other scientific publications. These studies were also discussed at a joint meeting of the Arthritis Advisory Committee and Drug Safety and Risk Management Advisory Committee held on February 10-11, 2014.

RECOMMENDATION: Patients and health care professionals should remain alert for heart-related side effects the entire time that NSAIDs are being taken. Patients taking NSAIDs should seek medical attention immediately if they experience symptoms such as chest pain, shortness of breath or trouble breathing, weakness in one part or side of their body, or slurred speech.

For more information visit the FDA website at: and .


  • Cardiovascular Risk
  • Possible increased risk of serious (sometimes fatal) cardiovascular thrombotic events (e.g., MI, stroke).1 Risk may increase with duration of use.1 Individuals with cardiovascular disease or risk factors for cardiovascular disease may be at increased risk.1 (See Cardiovascular Effects under Cautions.)

  • Contraindicated for the treatment of pain in the setting of CABG surgery.1

  • GI Risk
  • Increased risk of serious (sometimes fatal) GI events (e.g., bleeding, ulceration, perforation of the stomach or intestine).1 Serious GI events can occur at any time and may not be preceded by warning signs and symptoms.1 Geriatric individuals are at greater risk for serious GI events.1 (See GI Effects under Cautions.)


Prototypical NSAIA;1 prodrug with little pharmacologic activity until oxidized in the liver to form an active metabolite that is structurally similar to naproxen.1 2 3

Uses for Nabumetone

Consider potential benefits and risks of nabumetone therapy as well as alternative therapies before initiating therapy with the drug.1 Use lowest effective dosage and shortest duration of therapy consistent with the patient’s treatment goals.1

Inflammatory Diseases

Symptomatic treatment of osteoarthritis and rheumatoid arthritis.1

Nabumetone Dosage and Administration


  • Consider potential benefits and risks of nabumetone therapy as well as alternative therapies before initiating therapy with the drug.1


Oral Administration

Administer orally once or twice daily without regard to meals.1


To minimize the potential risk of adverse cardiovascular and/or GI events, use lowest effective dosage and shortest duration of therapy consistent with the patient’s treatment goals.1 Adjust dosage based on individual requirements and response; attempt to titrate to the lowest effective dosage.1


Inflammatory Diseases
Osteoarthritis or Rheumatoid Arthritis

Initially, 1 g once daily.1 May increase dosage to 1.5–2 g daily, given as a single daily dose or 2 divided doses.1

Patients weighing <50 kg may be less likely to need dosages >1 g daily.1

Prescribing Limits


Inflammatory Diseases
Osteoarthritis or Rheumatoid Arthritis

Maximum 2 g daily.1

Special Populations

Renal Impairment

Dosage adjustment not necessary in patients with mild renal impairment (Clcr >50 mL/minute).1

In patients with moderate renal impairment (Clcr 30–49 mL/minute), initiate at ≤750 mg daily (maximum initial dosage is 750 mg daily).1 Monitor renal function; may increase dosage to 1.5 g daily.1

In patients with severe renal impairment (Clcr <30 mL/minute), initiate at ≤500 mg daily (maximum inital dosage is 500 mg daily).1 Monitor renal function; may increase dosage to 1 g daily.1

Cautions for Nabumetone


Pending revision, the material in this section should be considered in light of more recently available information in the MedWatch notification at the beginning of this monograph.

  • Known hypersensitivity to nabumetone or any ingredient in the formulation.1

  • History of asthma, urticaria, or other sensitivity reaction precipitated by aspirin or other NSAIAs.1 2

  • Treatment of perioperative pain in the setting of CABG surgery.1



Cardiovascular Effects

Selective COX-2 inhibitors have been associated with an increased risk of serious adverse cardiovascular thrombotic events in certain situations.1 Several prototypical NSAIAs also have been associated with an increased risk of cardiovascular events.4 5 6 Current data insufficient to assess risk associated with nabumetone.4 5 6

Use NSAIAs with caution and careful monitoring (e.g., monitor for development of cardiovascular events), and at the lowest effective dosage for the shortest duration necessary.1

Short-term use to relieve acute pain, especially at low dosages, does not appear to be associated with increased risk of serious cardiovascular events (except immediately following CABG surgery).a

No consistent evidence that concomitant use of low-dose aspirin mitigates the increased risk of serious adverse cardiovascular events associated with NSAIAs.1 (See Specific Drugs under Interactions.)

Hypertension and worsening of preexisting hypertension reported; either event may contribute to the increased incidence of cardiovascular events.1 Use with caution in patients with hypertension; monitor BP.1 Impaired response to certain diuretics may occur.1 (See Specific Drugs under Interactions.)

Fluid retention and edema reported.1 Caution in patients with fluid retention or heart failure.1

GI Effects

Serious GI toxicity (e.g., bleeding, ulceration, perforation) can occur with or without warning symptoms; increased risk in those with a history of GI bleeding or ulceration, geriatric patients, smokers, those with alcohol dependence, and those in poor general health.1

For patients at high risk for complications from NSAIA-induced GI ulceration (e.g., bleeding, perforation), consider concomitant use of misoprostol; alternatively, consider concomitant use of a proton-pump inhibitor (e.g., omeprazole) or use of an NSAIA that is a selective inhibitor of COX-2 (e.g., celecoxib).

Renal Effects

Direct renal injury, including renal papillary necrosis, reported in patients receiving long-term NSAIA therapy.1

Potential for overt renal decompensation.1 Increased risk of renal toxicity in patients with renal or hepatic impairment or heart failure, in patients with volume depletion, in geriatric patients, and in those receiving a diuretic, ACE inhibitor, or angiotensin II receptor antagonist.1 c (See Renal Impairment under Cautions.)

Sensitivity Reactions

Hypersensitivity Reactions

Anaphylactoid reactions reported.1

Immediate medical intervention and discontinuance for anaphylaxis.1

Avoid in patients with aspirin triad (aspirin sensitivity, asthma, nasal polyps); caution in patients with asthma.1

Dermatologic Reactions

Serious skin reactions (e.g., exfoliative dermatitis, Stevens-Johnson syndrome, toxic epidermal necrolysis) reported; can occur without warning.1 Discontinue at first appearance of rash or any other sign of hypersensitivity (e.g., blisters, fever, pruritus).1

Photosensitivity Reactions

Photosensitivity reactions possible.1

General Precautions

Hepatic Effects

Severe reactions including jaundice, fatal fulminant hepatitis, liver necrosis, and hepatic failure (sometimes fatal) reported rarely with NSAIAs.1

Elevations of serum ALT or AST reported.1

Monitor for symptoms and/or signs suggesting liver dysfunction; monitor abnormal liver function test results.1 Discontinue if signs or symptoms of liver disease or systemic manifestations (e.g., eosinophilia, rash) occur or if liver function test abnormalities persist or worsen.1

Hematologic Effects

Anemia reported rarely.1 Determine hemoglobin concentration or hematocrit in patients receiving long-term therapy if signs or symptoms of anemia occur.1

May inhibit platelet aggregation and prolong bleeding time.1

Other Precautions

Not a substitute for corticosteroid therapy; not effective in the management of adrenal insufficiency.1

May mask certain signs of infection.1

Obtain CBC and chemistry profile periodically during long-term use.1

Specific Populations


Category C.1 Avoid use in third trimester because of possible premature closure of the ductus arteriosus.1


Active metabolite is distributed into milk in rats; not known whether nabumetone or its metabolites are distributed into milk in humans.1 Discontinue nursing or the drug.1

Pediatric Use

Safety and efficacy not established in children.1

Geriatric Use

Caution advised.1 Safety and efficacy profiles similar to those in younger adults.1 However, fatal adverse GI effects reported more frequently in geriatric patients than in younger adults.1

Hepatic Impairment

Caution advised in patients with severe hepatic impairment, since formation of the active metabolite depends on biotransformation in the liver.1

Renal Impairment

Use with caution in patients with renal disease.1 Use not recommended in patients with advanced renal disease; close monitoring of renal function advised if used.1

Dosage adjustments necessary in patients with moderate or severe renal impairment.1 (See Renal Impairment under Dosage and Administration.)

Oxidized and conjugated metabolites that are excreted in urine may accumulate in patients with renal failure, potentially resulting in adverse effects.1

Common Adverse Effects

Abdominal pain, constipation, diarrhea, dizziness, dyspepsia, edema, flatulence, headache, nausea, positive stool guaiac test, pruritus, rash, tinnitus.1

Interactions for Nabumetone

Protein-bound Drugs

Could be displaced from binding sites by, or could displace from binding sites, other protein-bound drugs.1

Specific Drugs




ACE inhibitors

Reduced BP response to ACE inhibitor1

Possible deterioration of renal function in individuals with renal impairmentc

Monitor BP1

Angiotensin II receptor antagonists

Reduced BP response to angiotensin II receptor antagonistc

Possible deterioration of renal function in individuals with renal impairmentc

Monitor BPc

Antacids (aluminum-containing)

No effect on 6-methoxy-2-naphthylacetic acid (6MNA) bioavailability1


Increased risk of GI ulceration and other complications1

No consistent evidence that low-dose aspirin mitigates the increased risk of serious cardiovascular events associated with NSAIAs1

Manufacturer states that concomitant use not recommended1

Diuretics (furosemide, thiazides)

Reduced natriuretic effects possible1

Monitor for diuretic efficacy and renal failure1


Increased plasma lithium concentrations1

Monitor for lithium toxicity1


Possible toxicity associated with increased plasma methotrexate concentrations1

Caution advised1


Possibility of bleeding complications1

Caution advised1

Nabumetone Pharmacokinetics



Well absorbed following oral administration.1 Rapidly biotransformed to active metabolite, 6MNA; peak plasma concentration of 6MNA usually attained within 2.5–4 hours.1 Approximately 35% of a 1-g dose is metabolized to 6MNA.1 Unchanged nabumetone is not detected in plasma.1


Food increases rate of nabumetone absorption; increases rate but not extent of metabolism to 6MNA.1

Special Populations

In geriatric patients, steady-state plasma 6MNA concentrations are higher than in younger individuals.1


Plasma Protein Binding

6MNA: >99%.1



6MNA is extensively metabolized in the liver to inactive metabolites; 6MNA does not appear to undergo enterohepatic recirculation.1

Elimination Route

Excreted mainly in urine as metabolites of 6MNA and metabolites of nabumetone.1


6MNA: about 23–30 hours.1

Special Populations

In patients with moderate renal impairment (Clcr 30–49 mL/minute) and severe renal impairment (Clcr <30 mL/minute), elimination half-life of 6MNA increased.1





25°C (may be exposed to 15–30°C).1


  • Inhibits cyclooxygenase-1 (COX-1) and COX-2.1

  • Pharmacologic actions similar to those of other prototypical NSAIAs; exhibits anti-inflammatory, analgesic, and antipyretic activity.1

Advice to Patients

Pending revision, the material in this section should be considered in light of more recently available information in the MedWatch notification at the beginning of this monograph.

  • Importance of reading the medication guide for NSAIAs that is provided each time the drug is dispensed.1

  • Risk of serious cardiovascular events with long-term use.1

  • Risk of GI bleeding and ulceration.1

  • Risk of serious skin reactions.1 Risk of anaphylactoid and other sensitivity reactions.1

  • Risk of hepatotoxicity.1

  • Importance of notifying clinician if signs and symptoms of a cardiovascular event (chest pain, dyspnea, weakness, slurred speech) occur.1

  • Importance of notifying clinician if signs and symptoms of GI ulceration or bleeding, unexplained weight gain, or edema develops.1

  • Importance of discontinuing nabumetone and contacting clinician if rash or other signs of hypersensitivity (blisters, fever, pruritus) develop.1 Importance of seeking immediate medical attention if an anaphylactic reaction occurs.1

  • Importance of discontinuing therapy and contacting clinician immediately if signs and symptoms of hepatotoxicity (nausea, fatigue, lethargy, pruritus, jaundice, upper right quadrant tenderness, flu-like symptoms) occur.1

  • Importance of women informing clinicians if they are or plan to become pregnant or plan to breast-feed.1 Importance of avoiding nabumetone in late pregnancy (third trimester).1

  • Importance of informing clinicians of existing or contemplated concomitant therapy, including prescription and OTC drugs.1

  • Importance of informing patients of other important precautionary information.1 (See Cautions.)


Excipients in commercially available drug preparations may have clinically important effects in some individuals; consult specific product labeling for details.

Please refer to the ASHP Drug Shortages Resource Center for information on shortages of one or more of these preparations.

* available from one or more manufacturer, distributor, and/or repackager by generic (nonproprietary) name



Dosage Forms


Brand Names



Tablets, film-coated

500 mg*

Nabumetone Tablets

Par, Sandoz, Teva

750 mg*

Nabumetone Tablets

Par, Sandoz, Teva

AHFS DI Essentials. © Copyright, 2016, American Society of Health-System Pharmacists, Inc., 7272 Wisconsin Avenue, Bethesda, Maryland 20814.

Date published: May 01, 2004
Last reviewed: August 27, 2015
Date modified: February 08, 2016


1. GlaxoSmithKline. Relafen (nabumetone) tablets prescribing information. Research Triangle Park, NC; 2006 Feb.

2. Dahl SL. Nabumetone: a “nonacidic” nonsteroidal antiinflammatory drug. Ann Pharmacother. 1993; 27:456-63. [IDIS 313113] [PubMed 8477124]

3. Friedel HA, Langtry HD, Buckley MM. Nabumetone: a reappraisal of its pharmacology and therapeutic use in rheumatic diseases. Drugs. 1993; 45:131-56. [PubMed 7680981]

4. McGettigan P, Henry D. Cardiovascular risk and inhibition of cyclooxygenase: a systematic review of observational studies of selective and nonselective inhibitors of cyclooxygenase 2. JAMA. 2006; 296: 1633-44. [PubMed 16968831]

5. Kearney PM, Baigent C, Godwin J et al. Do selective cyclo-oxygenase-2 inhibitors and traditional non-steroidal anti-inflammatory drugs increase the risk of atherothrombosis? Meta-analysis of randomised trials. BMJ. 2006; 332: 1302-5. [PubMed 16740558]

6. Graham DJ. COX-2 inhibitors, other NSAIDs, and cardiovascular risk; the seduction of common sense. JAMA. 2006; 296:1653-6. [PubMed 16968830]

a. Food and Drug Administration. Analysis and recommendations for Agency action regarding non-steroidal anti-inflammatory drugs and cardiovascular risk. 2005 Apr 6. From FDA web site ().

c. Merck & Co., Inc. Dolobid (diflunisal) tablets prescribing information. Whitehouse Station, NJ; 2006 Feb.