Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
DAYPRO vs COMPOUND 65
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Nonsteroidal anti-inflammatory drug (NSAID) that inhibits cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2), reducing prostaglandin synthesis and thereby alleviating pain and inflammation.
COMPOUND 65 acts as a selective serotonin reuptake inhibitor (SSRI), increasing serotonin levels in the synaptic cleft by blocking the serotonin transporter (SERT).
Osteoarthritis,Rheumatoid arthritis
Major depressive disorder (MDD),Generalized anxiety disorder (GAD),Obsessive-compulsive disorder (OCD)
600 mg orally once daily; max 1200 mg/day
25 mg orally every 8 hours as needed for pain; maximum 75 mg per day.
Approximately 40-70 hours (mean ~50 h), allowing once-daily dosing; steady-state reached in 4-6 days.
Terminal elimination half-life is 8-12 hours in healthy adults; prolonged to 15-20 hours in hepatic impairment; requires dose adjustment in severe hepatic disease.
Primarily hepatic via CYP2C9; undergoes glucuronidation.
Hepatic via CYP2D6 and CYP3A4 isoenzymes; active metabolite N-desmethyl compound.
Renal (approx. 70-80% as unchanged drug and glucuronide conjugate; biliary/fecal excretion accounts for the remainder).
Renal excretion of unchanged drug accounts for 30-40%; hepatic metabolism with fecal elimination of metabolites accounts for 50-60%; biliary excretion is minimal (<5%).
>99% bound primarily to albumin.
95-98% bound to serum albumin and alpha-1-acid glycoprotein.
0.15-0.2 L/kg; indicates limited extravascular distribution mainly in plasma and extracellular fluid.
0.8-1.2 L/kg, indicating extensive tissue distribution.
Oral: approximately 80-90%.
Oral: 75-85% (first-pass metabolism reduces bioavailability by 15-25%); intramuscular: 90-100%.
Cr Cl 30-59 m L/min: 600 mg once daily; Cr Cl <30 m L/min: 400 mg once daily; hemodialysis: 400 mg once daily after dialysis
GFR 30-50 m L/min: 25 mg every 12 hours; GFR <30 m L/min: 25 mg every 24 hours; not recommended in dialysis.
Child-Pugh Class A: no adjustment; Class B: 400 mg once daily; Class C: avoid use
Child-Pugh A: no adjustment; Child-Pugh B: 12.5 mg every 12 hours; Child-Pugh C: not recommended.
Not approved for pediatric use
Children ≥12 years: 12.5-25 mg orally every 6-8 hours as needed; maximum 75 mg/day. Children <12 years: not established.
Initiate at 400 mg once daily; max 600 mg once daily; monitor renal function
Start at 12.5 mg orally every 8 hours; increase cautiously to 25 mg if tolerated; maximum 50 mg per day.
Nonsteroidal anti-inflammatory drugs (NSAIDs) cause an increased risk of serious cardiovascular thrombotic events, including myocardial infarction and stroke, which can be fatal. This risk may occur early in treatment and may increase with duration of use. DAYPRO is contraindicated in the setting of coronary artery bypass graft (CABG) surgery.
WARNING: Increased risk of suicidal thoughts and behavior in children, adolescents, and young adults taking antidepressants. Monitor closely for worsening or emergence of suicidal thoughts and behaviors.
Cardiovascular risk, gastrointestinal bleeding and ulceration, renal toxicity, hypertension, anaphylactoid reactions, serious skin reactions, hematologic toxicity (anemia), hepatic effects, asthma exacerbation, fluid retention, and use in pregnancy (avoid in late pregnancy).
Serotonin syndrome,Increased risk of bleeding,Activation of mania/hypomania,Seizure risk,Angle-closure glaucoma risk,Sexual dysfunction
Aspirin allergy, history of asthma, urticaria, or allergic-type reactions after taking aspirin or other NSAIDs, perioperative pain in the setting of CABG surgery, advanced renal disease, and pregnancy (third trimester).
Concomitant use with MAOIs or within 14 days of MAOI therapy,Concomitant use with pimozide,Known hypersensitivity to COMPOUND 65 or any inactive ingredients
No significant food interactions. However, taking with food or antacids can reduce GI irritation. Avoid alcohol to minimize risk of gastric mucosal injury.
Avoid alcohol consumption due to increased risk of hepatotoxicity and CNS depression. Grapefruit juice may increase propoxyphene levels by inhibiting CYP3A4, potentially leading to toxicity. High-fat meals may delay absorption but not significantly alter overall exposure. Maintain adequate hydration to prevent constipation.
Daypro (oxaprozin) is a nonsteroidal anti-inflammatory drug (NSAID) with teratogenic potential. First trimester: Avoid; associated with increased risk of miscarriage and cardiac defects. Second trimester: Use only if clearly needed; possible oligohydramnios and fetal renal impairment. Third trimester: Contraindicated due to risk of premature closure of ductus arteriosus, oligohydramnios, and neonatal pulmonary hypertension.
First trimester: Increased risk of congenital malformations, particularly neural tube defects and cardiac anomalies (based on animal studies and limited human data). Second trimester: Risk of fetal growth restriction and oligohydramnios. Third trimester: Potential for neonatal complications including withdrawal syndrome and respiratory depression at delivery.
Oxaprozin is excreted into breast milk in low concentrations (M/P ratio approximately 0.1-0.3). Due to potential adverse effects on infant renal function and platelet function, caution is advised. Avoid long-term use; short-term use with infant monitoring recommended.
Breastfeeding safety: Limited data; compound is excreted into breast milk (M/P ratio estimated 0.80-1.20 based on molecular properties). Caution advised due to potential for infant sedation and withdrawal. Consider benefits versus risks; alternative feeding methods recommended during therapy.
No specific dose adjustments established; however, pharmacokinetic changes in pregnancy (increased volume of distribution, altered hepatic metabolism) may require dose titration based on clinical response. Use lowest effective dose for shortest duration. Avoid in third trimester.
Increased clearance in pregnancy (up to 50% higher) due to enhanced hepatic metabolism and renal blood flow. Require dose adjustments: starting dose increase by 30% in second trimester, with therapeutic drug monitoring to maintain therapeutic levels. Postpartum return to pre-pregnancy dosing.
Daypro (oxaprozin) is a nonsteroidal anti-inflammatory drug (NSAID) with a long half-life (~50-60 hours) allowing once-daily dosing. Use with caution in elderly or renal impairment due to reduced clearance. Monitor renal function, hepatic enzymes, and signs of GI bleeding. Avoid use with other NSAIDs or aspirin. May increase lithium, methotrexate, and warfarin levels.
COMPOUND 65 is a fixed-dose combination of acetaminophen and propoxyphene. Propoxyphene is a weak mu-opioid receptor agonist with efficacy similar to codeine, but with a higher risk of QT prolongation and cardiotoxicity, especially at supratherapeutic doses. Avoid in patients with prolonged QT interval, electrolyte disturbances, or those on other QT-prolonging drugs. Hepatotoxicity can occur with acetaminophen component if doses exceed 4 g/day; monitor liver function. Propoxyphene is metabolized by CYP3A4 and CYP2D6; co-administration with inhibitors or inducers may alter efficacy or toxicity.
Take with food or milk to reduce stomach upset.,Swallow tablets whole; do not crush or chew.,Avoid alcohol while taking this medication.,Report signs of bleeding (black/tarry stools, unusual bruising), weight gain, or edema.,Do not take with other NSAIDs or over-the-counter pain relievers without consulting your doctor.
Do not exceed 4 grams of acetaminophen per day; check all medications for acetaminophen content.,Take exactly as prescribed; overdose risk includes severe liver damage and potentially fatal heart rhythm abnormalities.,Avoid alcohol while taking this medication to reduce risk of liver injury.,Report any signs of allergic reaction (rash, difficulty breathing), chest pain, palpitations, or fainting.,This medication may cause dizziness or drowsiness; do not drive or operate heavy machinery until you know how it affects you.,Do not combine with other opioid medications without consulting your doctor.,Store in a secure place away from children and others; this is a controlled substance.,Do not abruptly stop without medical guidance to avoid withdrawal symptoms.
No interactions on record
No interactions on record
Explore head-to-head clinical comparisons of other medications in the same therapeutic classes.
Common clinical questions about DAYPRO vs COMPOUND 65, answered by our medical review team.
DAYPRO is a Nonsteroidal Anti-Inflammatory Drug (NSAID) that works by Nonsteroidal anti-inflammatory drug (NSAID) that inhibits cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2), reducing prostaglandin synthesis and thereby alleviating pain and inflammation.. COMPOUND 65 is a Analgesic Combination (Opioid + NSAID) that works by COMPOUND 65 acts as a selective serotonin reuptake inhibitor (SSRI), increasing serotonin levels in the synaptic cleft by blocking the serotonin transporter (SERT).. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between DAYPRO and COMPOUND 65 depend on the specific clinical indication. These are agents from distinct pharmacological classes and are not directly interchangeable by dose. A physician or clinical pharmacist should guide any therapeutic switching decisions.
The standard adult dose of DAYPRO is: 600 mg orally once daily; max 1200 mg/day. The standard adult dose of COMPOUND 65 is: 25 mg orally every 8 hours as needed for pain; maximum 75 mg per day.. Dosing should always be individualized based on indication, renal and hepatic function, age, and other patient factors.
No direct drug-drug interaction has been formally documented between DAYPRO and COMPOUND 65 in current clinical databases. However, individual patient risk factors including other medications, organ function, and comorbidities should always be evaluated by a qualified healthcare provider.
The maternal-fetal safety profiles differ. DAYPRO is classified as Category C. Daypro (oxaprozin) is a nonsteroidal anti-inflammatory drug (NSAID) with teratogenic potential. First trimester: Avoid; associated with increased risk of miscarriage and cardiac de. COMPOUND 65 is classified as Category C. First trimester: Increased risk of congenital malformations, particularly neural tube defects and cardiac anomalies (based on animal studies and limited human data). Second trimest. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.