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Generic Name: Oxaprozin
Class: Other Nonsteroidal Anti-inflammatory Agents
VA Class: MS120
Chemical Name: 4,5-Diphenyl-2-oxazolepropionic acid
Molecular Formula: C18H15NO3
CAS Number: 21256-18-8

Medically reviewed by Last updated on Nov 11, 2019.


    Cardiovascular Risk
  • Increased risk of serious (sometimes fatal) cardiovascular thrombotic events (e.g., MI, stroke).1 500 502 508 Risk may occur early in treatment and may increase with duration of use.500 502 505 506 508 (See Cardiovascular Thrombotic Effects under Cautions.)

  • Contraindicated in the setting of CABG surgery.508

    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 2 3 4 5 6 7 8 propionic acid derivative.1 2 3 4 5 6 7 8

Uses for Daypro

Consider potential benefits and risks of oxaprozin 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 2 3

Management of juvenile rheumatoid arthritis in children 6-16 years of age.1

Daypro Dosage and Administration


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


Oral Administration

Administer orally once daily;1 2 3 6 7 divided doses may improve tolerance in some patients.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 lowest effective dosage.1

Pediatric Patients

Inflammatory Disease
Juvenile Rheumatoid Arthritis
Children 6–16 years of age: Dosage Based on Child’s Body Weight1

Weight (kg)



600 mg once daily


900 mg once daily


1.2 g once daily


Inflammatory Diseases
Osteoarthritis or Rheumatoid Arthritis

Initially, 1.2 g once daily.1 2 3 Reserve long-term use of dosages >1.2 g daily for adults with severe disease who weigh >50 kg, have normal renal and hepatic function, and low risk for GI toxicity.1

If rapid onset of action needed, administer one-time loading dose of 1.2–1.8 g (up to 26 mg/kg).1

Patients with low body weight: Initially, 600 mg once daily.1 May increase to 1.2 g daily if needed.1

Prescribing Limits

Pediatric Patients

Juvenile Rheumatoid Arthritis

Doses >1.2 g daily not studied.1


Inflammatory Diseases
Osteoarthritis or Rheumatoid Arthritis

Maximum 1.8 g or 26 mg/kg daily (whichever is lower).1 Maximum loading dose is 26 mg/kg.1

Special Populations

Renal Impairment

Severe renal impairment and in those undergoing hemodialysis: Initially, 600 mg once daily.1 3 8 May increase to 1.2 g daily if needed.1 8 Supplemental doses after hemodialysis not needed.1

Hepatic Impairment

Dosage adjustment not needed in patients with well-compensated cirrhosis.1 2 3

Geriatric Patients

Dosage adjustment may be necessary in patients with low body weight, decreased renal function, or age-related concomitant disease.1

Cautions for Daypro


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

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

  • In the setting of CABG surgery.508



Cardiovascular Thrombotic Effects

NSAIAs (selective COX-2 inhibitors, prototypical NSAIAs) increase the risk of serious adverse cardiovascular thrombotic events (e.g., MI, stroke) in patients with or without cardiovascular disease or risk factors for cardiovascular disease.500 502 508

Findings of FDA review of observational studies, meta-analysis of randomized controlled trials, and other published information500 501 502 indicate that NSAIAs may increase the risk of such events by 10–50% or more, depending on the drugs and dosages studied.500

Relative increase in risk appears to be similar in patients with or without known underlying cardiovascular disease or risk factors for cardiovascular disease, but the absolute incidence of serious NSAIA-associated cardiovascular thrombotic events is higher in those with cardiovascular disease or risk factors for cardiovascular disease because of their elevated baseline risk.500 502 506 508

Increased risk may occur early (within the first weeks) following initiation of therapy and may increase with higher dosages and longer durations of use.500 502 505 506 508

In controlled studies, increased risk of MI and stroke observed in patients receiving a selective COX-2 inhibitor for analgesia in first 10–14 days following CABG surgery.508

In patients receiving NSAIAs following MI, increased risk of reinfarction and death observed beginning in the first week of treatment.505 508

Increased 1-year mortality rate observed in patients receiving NSAIAs following MI;500 508 511 absolute mortality rate declined somewhat after the first post-MI year, but the increased relative risk of death persisted over at least the next 4 years.508 511

Some systematic reviews of controlled observational studies and meta-analyses of randomized studies suggest naproxen may be associated with lower risk of cardiovascular thrombotic events compared with other NSAIAs.11 12 13 500 501 502 503 506 FDA states that limitations of these studies and indirect comparisons preclude definitive conclusions regarding relative risks of NSAIAs.500

Use NSAIAs with caution and careful monitoring (e.g., monitor for development of cardiovascular events throughout therapy, even in those without prior cardiovascular symptoms) and at the lowest effective dosage for the shortest duration necessary.1 500 508

Some clinicians suggest that it may be prudent to avoid NSAIA use, whenever possible, in patients with cardiovascular disease.505 511 512 516 Avoid use in patients with recent MI unless benefits of therapy are expected to outweigh risk of recurrent cardiovascular thrombotic events; if used, monitor for cardiac ischemia.508 Contraindicated in the setting of CABG surgery.508

No consistent evidence that concomitant use of low-dose aspirin mitigates the increased risk of serious adverse cardiovascular events.1 502 508 (See Specific Drugs under Interactions.)

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 proton pump inhibitor (e.g., omeprazole) or use of an NSAIA that is a selective inhibitor of COX-2 (e.g., celecoxib).


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 ACE inhibitors, angiotensin II receptor antagonists, β-blockers, and certain diuretics may occur.1 508 (See Specific Drugs under Interactions.)

Heart Failure and Edema

Fluid retention and edema reported.1 508

NSAIAs (selective COX-2 inhibitors, prototypical NSAIAs) may increase morbidity and mortality in patients with heart failure.500 501 504 507 508

NSAIAs may diminish cardiovascular effects of diuretics, ACE inhibitors, or angiotensin II receptor antagonists used to treat heart failure or edema.508 (See Specific Drugs under Interactions.)

Manufacturer recommends avoiding use in patients with severe heart failure unless benefits of therapy are expected to outweigh risk of worsening heart failure; if used, monitor for worsening heart failure.508

Some experts recommend avoiding use, whenever possible, in patients with reduced left ventricular ejection fraction and current or prior symptoms of heart failure.507

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 geriatric patients, in patients with volume depletion, and in those receiving a diuretic, ACE inhibitor, or angiotensin II receptor antagonist.1 b

Sensitivity Reactions


Anaphylactoid reactions (e.g., anaphylaxis, angioedema) 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 signs of hypersensitivity (e.g., blisters, fever, pruritus).1


Rash on sun-exposed areas of the body reported.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 manifestation (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


Distributed into milk in rats; not known whether distributed into human milk.1 Discontinue nursing or the drug.1

Pediatric Use

Safety and efficacy not established in children <6 years of age.1

Safety and efficacy in pediatric patients 6–16 years of age with juvenile rheumatoid arthritis supported by studies in adults with rheumatoid arthritis and by safety and pharmacokinetic data from trials in children with juvenile rheumatoid arthritis.1

Geriatric Use

No overall differences in efficacy or safety were observed between geriatric and younger adults.1 Possibility exists of greater sensitivity in some geriatric individuals.1

Caution advised.1 Geriatric adults appear to tolerate NSAIA-induced adverse effects less well than younger individuals.1

Select dosage with caution because of age-related decreases in renal function.1 May be useful to monitor renal function.1

Hepatic Impairment

Use with caution in patients with severe hepatic impairment.1

Renal Impairment

Use not recommended in patients with advanced renal disease; close monitoring of renal function advised if used.1 Dosage adjustment needed.1 (See Renal Impairment under Dosage and Administration.)

Common Adverse Effects

Abdominal pain, anorexia, constipation, diarrhea, flatulence, GI ulcers, GI bleeding/perforation, dyspepsia, heartburn, nausea, vomiting, renal function abnormalities, anemia, confusion, depression, sleep disturbance, dizziness, dysuria or increased frequency, edema, liver function test abnormalities, headache, prolonged bleeding time, pruritus, rash, sedation, somnolence, tinnitus.1

Interactions for Daypro

Specific Drugs




ACE inhibitors

Reduced BP response to ACE inhibitor 1

Monitor BP1


Pharmacokinetic interaction unlikely1

Angiotensin II receptor antagonists

Reduced BP response to angiotensin II receptor antagonistb

Monitor BPb


Change in oxaprozin bioavailability unlikely1


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 NSAIAs 1 502 508 a

Possible pharmacokinetic interaction (altered plasma protein binding)1

Manufacturer states that concomitant use not recommended1

β-Adrenergic blocking agents

Reduced BP response to metoprolol reported1

Monitor BP1

Diuretics (furosemide, thiazides)

Reduced natriuretic effects possible1

Monitor for diuretic efficacy and renal failure1

Estrogens, conjugated

Pharmacokinetic interaction unlikely1


Pharmacokinetic interaction; no effect on hypoglycemic effects1

Monitor blood glucose if concomitant therapy initiated1

Histamine H2-receptor antagonists (cimetidine, ranitidine)

Decreased clearance of oxaprozin1


Increased plasma lithium concentrations 1

Monitor for lithium toxicity1


Possible toxicity associated with increased plasma methotrexate concentration1

Caution advised1


Possibility of bleeding complications1

Caution advised1

Daypro Pharmacokinetics



Well absorbed following oral administration.1


Food may reduce the rate of absorption, but does not affect extent of absorption.1 2 3 4 6



Distributed into synovial tissues in patients with rheumatoid arthritis.1

Plasma Protein Binding

99% (mainly albumin).1



Metabolized, principally in the liver, to inactive metabolites.1

Elimination Route

Excreted in urine (65%) and in feces (35%) as metabolites; approximately 5% is excreted in urine as unchanged drug.1


Approximately 38–44 hours.1

Special Populations

Renal clearance decreased in patients with renal impairment; renal clearance contributes minimally to excretion of oxaprozin.1 Not removed by hemodialysis or continuous ambulatory peritoneal dialysis (CAPD).1





Tight, light resistant containers at 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

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

  • Risk of serious cardiovascular events (e.g., MI, stroke).1 500 508

  • Risk of GI toxicity and ulceration.1

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

  • Risk of hepatotoxicity.1

  • Importance of seeking immediate medical attention if signs and symptoms of a cardiovascular event (chest pain, dyspnea, weakness, slurred speech) occur.1 500 508

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

  • Importance of discontinuing therapy 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

  • Risk of heart failure or edema; importance of reporting dyspnea, unexplained weight gain, or edema.508

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

  • Importance of informing clinicians of existing or contemplated concomitant therapy, including prescription and OTC drugs, as well as any concomitant diseases.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

600 mg*

Daypro (scored)


AHFS DI Essentials™. © Copyright 2020, Selected Revisions November 21, 2016. American Society of Health-System Pharmacists, Inc., 4500 East-West Highway, Suite 900, Bethesda, Maryland 20814.


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2. Miller LG. Oxaprozin: a once-daily nonsteroidal anti- inflammatory drug. Clin Pharm. 1992; 11:591-603.

3. Todd PA, Brogden RN. Oxaprozin: a preliminary review of its pharmacodynamic and pharmacokinetic properties, and therapeutic efficacy. Drugs. 1986; 32:291-312.

4. Chiang ST, Knowles JA, Hubsher JA et al. Effects of food on oxaprozin bioavailability. J Clin Pharmacol. 1984; 24:381-5.

5. Lewis AJ, Carlson RP, Chang J et al. The pharmacological profile of oxaprozin, an antiinflammatory and analgesic agent with low gastrointestinal toxicity. Curr Ther Res. 1983; 34:777-94.

6. Janssen FW, Chiang ST, Walker BR et al. Disposition of oxaprozin in healthy subjects and certain disease states. Curr Ther Res. 1984; 35:363-76.

7. Greenblatt DJ, Matlis R, Scavone JM et al. Oxaprozin pharmacokinetics in the elderly. Br J Clin Pharmacol. 1985; 19:373-8.

8. Chiang ST, Morrison G, Knowles JA et al. Oxaprozin disposition in renal disease. Clin Pharmacol Ther. 1982; 31:509-15.

9. Searle. Skokie, IL: Personal communication.

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a. Food and Drug Administration. Analysis and recommendations for agency action regarding non-steroidal anti-inflammatory drugs and cardiovascular risk. 2005 Apr 6.

b. Merck & Co. Clinoril (sulindac) tablets prescribing information. Whitehouse Station, NJ; 2006 Feb.

500. Food and Drug Administration. Drug safety communication: FDA strengthens warning that non-aspirin nonsteroidal anti-inflammatory drugs (NSAIDs) can cause heart attacks or strokes. Silver Spring, MD; 2015 Jul 9. From the FDA web site. Accessed 2016 Mar 22.

501. Coxib and traditional NSAID Trialists' (CNT) Collaboration, Bhala N, Emberson J et al. Vascular and upper gastrointestinal effects of non-steroidal anti-inflammatory drugs: meta-analyses of individual participant data from randomised trials. Lancet. 2013; 382:769-79.

502. Food and Drug Administration. FDA briefing document: Joint meeting of the arthritis advisory committee and the drug safety and risk management advisory committee, February 10-11, 2014. From FDA web site

503. Trelle S, Reichenbach S, Wandel S et al. Cardiovascular safety of non-steroidal anti-inflammatory drugs: network meta-analysis. BMJ. 2011; 342:c7086.

504. Gislason GH, Rasmussen JN, Abildstrom SZ et al. Increased mortality and cardiovascular morbidity associated with use of nonsteroidal anti-inflammatory drugs in chronic heart failure. Arch Intern Med. 2009; 169:141-9.

505. Schjerning Olsen AM, Fosbøl EL, Lindhardsen J et al. Duration of treatment with nonsteroidal anti-inflammatory drugs and impact on risk of death and recurrent myocardial infarction in patients with prior myocardial infarction: a nationwide cohort study. Circulation. 2011; 123:2226-35.

506. McGettigan P, Henry D. Cardiovascular risk with non-steroidal anti-inflammatory drugs: systematic review of population-based controlled observational studies. PLoS Med. 2011; 8:e1001098.

507. Yancy CW, Jessup M, Bozkurt B et al. 2013 ACCF/AHA guideline for the management of heart failure: a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines. J Am Coll Cardiol. 2013; 62:e147-239.

508. Pfizer. Daypro (oxaprozin) caplets prescribing information. New York, NY; 2016 May.

511. Olsen AM, Fosbøl EL, Lindhardsen J et al. Long-term cardiovascular risk of nonsteroidal anti-inflammatory drug use according to time passed after first-time myocardial infarction: a nationwide cohort study. Circulation. 2012; 126:1955-63.

512. Olsen AM, Fosbøl EL, Lindhardsen J et al. Cause-specific cardiovascular risk associated with nonsteroidal anti-inflammatory drugs among myocardial infarction patients--a nationwide study. PLoS One. 2013; 8:e54309.

516. Bavry AA, Khaliq A, Gong Y et al. Harmful effects of NSAIDs among patients with hypertension and coronary artery disease. Am J Med. 2011; 124:614-20.