Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
COMPOUND 65 vs IBU
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
COMPOUND 65 acts as a selective serotonin reuptake inhibitor (SSRI), increasing serotonin levels in the synaptic cleft by blocking the serotonin transporter (SERT).
Non-selective inhibitor of cyclooxygenase (COX-1 and COX-2), decreasing prostaglandin synthesis, thereby reducing inflammation, pain, and fever.
Major depressive disorder (MDD),Generalized anxiety disorder (GAD),Obsessive-compulsive disorder (OCD)
Rheumatoid arthritis,Osteoarthritis,Mild to moderate pain,Dysmenorrhea,Fever,Patent ductus arteriosus closure in neonates (off-label)
25 mg orally every 8 hours as needed for pain; maximum 75 mg per day.
200-800 mg orally every 6-8 hours as needed; maximum 3200 mg/day. For OTC use: 200-400 mg every 4-6 hours; max 1200 mg/day.
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.
Terminal elimination half-life: 2-4 hours in adults; prolonged in neonates (30 hours) and elderly (up to 6 hours). No accumulation with recommended dosing due to short t½.
Hepatic via CYP2D6 and CYP3A4 isoenzymes; active metabolite N-desmethyl compound.
Hepatic metabolism primarily via CYP2C9 to inactive metabolites; minor pathways include CYP2C8.
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%).
Renal (90% as conjugated metabolites, 10% unchanged), biliary/fecal (minor, <5%)
95-98% bound to serum albumin and alpha-1-acid glycoprotein.
99% bound primarily to albumin
0.8-1.2 L/kg, indicating extensive tissue distribution.
0.1-0.2 L/kg, indicating low tissue distribution; predominantly confined to plasma and extracellular fluid.
Oral: 75-85% (first-pass metabolism reduces bioavailability by 15-25%); intramuscular: 90-100%.
Oral: 80-100% (immediate-release), 70-90% (extended-release); Topical: approximately 5-10% systemic absorption; Intravenous: 100%.
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.
Cr Cl >30 m L/min: no adjustment. Cr Cl 10-30 m L/min: 200 mg every 12 hours; avoid if Cr Cl <10 m L/min.
Child-Pugh A: no adjustment; Child-Pugh B: 12.5 mg every 12 hours; Child-Pugh C: not recommended.
Child-Pugh A: no adjustment. Child-Pugh B: reduce dose by 50% or avoid. Child-Pugh C: contraindicated due to risk of hepatotoxicity.
Children ≥12 years: 12.5-25 mg orally every 6-8 hours as needed; maximum 75 mg/day. Children <12 years: not established.
6 months to 12 years: 5-10 mg/kg/dose every 6-8 hours; max 40 mg/kg/day. For juvenile idiopathic arthritis: 30-40 mg/kg/day divided every 6-8 hours; max 50 mg/kg/day.
Start at 12.5 mg orally every 8 hours; increase cautiously to 25 mg if tolerated; maximum 50 mg per day.
Initiate at lowest effective dose; consider 200 mg every 8-12 hours; monitor renal function and GI bleeding risk.
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.
NSAIDs cause an increased risk of serious cardiovascular thrombotic events, myocardial infarction, and stroke, which can be fatal. Risk may increase with duration of use. Contraindicated for treatment of peri-operative pain in coronary artery bypass graft (CABG) surgery.
Serotonin syndrome,Increased risk of bleeding,Activation of mania/hypomania,Seizure risk,Angle-closure glaucoma risk,Sexual dysfunction
Cardiovascular thrombotic events,Gastrointestinal bleeding, ulceration, and perforation,Hypertension,Heart failure exacerbation,Renal toxicity,Anaphylactic reactions,Serious skin reactions (e.g., Stevens-Johnson syndrome),Hematologic effects (anemia, bleeding)
Concomitant use with MAOIs or within 14 days of MAOI therapy,Concomitant use with pimozide,Known hypersensitivity to COMPOUND 65 or any inactive ingredients
History of asthma, urticaria, or allergic-type reactions after taking aspirin or other NSAIDs,Peri-operative pain in CABG surgery,Active gastrointestinal bleeding,Advanced renal disease,Third trimester of pregnancy
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.
Ibuprofen can increase the risk of stomach bleeding when taken with alcohol. No specific food restrictions, but taking with food or milk can reduce GI irritation.
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.
First and second trimester: Increased risk of miscarriage and congenital malformations (particularly cardiac defects) associated with NSAID use. Third trimester: Known risk of premature closure of ductus arteriosus, oligohydramnios, and neonatal renal impairment; contraindicated after 30 weeks gestation.
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.
Ibuprofen is excreted into breast milk in low concentrations (M/P ratio approximately 0.01-0.03). Considered compatible with breastfeeding by the American Academy of Pediatrics; use lowest effective dose for shortest duration.
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.
Increased plasma volume and renal clearance in pregnancy may reduce drug levels; however, no standard dose adjustment recommended. Use lowest effective dose, avoid in third trimester.
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.
Ibuprofen is a nonselective COX inhibitor with anti-inflammatory, analgesic, and antipyretic effects. Avoid in patients with aspirin allergy, active peptic ulcer, or severe renal impairment. Use lowest effective dose for shortest duration to minimize GI and cardiovascular risks. Not recommended in patients with advanced chronic kidney disease (e GFR <30 m L/min/1.73 m²). For acute pain, ibuprofen 200-400 mg every 6 hours PRN. Monitor for signs of GI bleeding, hypertension, and fluid retention.
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.
Take with food or milk to reduce stomach upset.,Do not exceed 1200 mg per day unless directed by your doctor.,Avoid alcohol while taking this medication.,Stop use and seek medical help if you experience chest pain, weakness, slurred speech, or signs of stomach bleeding (black/tarry stools, vomit that looks like coffee grounds).,Do not take with other NSAIDs or aspirin without consulting your healthcare provider.
No interactions on record
"Concomitant use of Ibuprofen (a nonsteroidal anti-inflammatory drug, NSAID) and Methylprednisolone (a systemic corticosteroid) synergistically increases the risk of gastrointestinal (GI) ulceration, bleeding, and perforation due to additive inhibition of prostaglandin synthesis and mucosal protection. Additionally, Ibuprofen may potentiate the immunosuppressive effects of Methylprednisolone, elevating infection risk. This interaction can lead to serious clinical outcomes, including acute GI hemorrhage, perforation, and impaired wound healing."
"The combination of olopatadine, an antihistamine with sedative properties, and ibuprofen, a nonsteroidal anti-inflammatory drug (NSAID), may result in additive central nervous system (CNS) depression, leading to increased sedation, dizziness, and impaired psychomotor function. Ibuprofen can inhibit the metabolism of olopatadine via competition for hepatic CYP450 enzymes, potentially elevating olopatadine plasma concentrations and prolonging its systemic effects. Clinically, patients may experience exacerbated drowsiness, reduced alertness, and increased risk of falls or accidents, especially in the elderly or those with compromised hepatic function."
"Ibuprofen, a nonsteroidal anti-inflammatory drug (NSAID), can decrease the metabolism of pioglitazone, a thiazolidinedione antidiabetic agent, by inhibiting cytochrome P450 2C8 (CYP2C8) enzyme activity. This inhibition elevates plasma concentrations of pioglitazone, potentially enhancing its hypoglycemic effects and increasing the risk of adverse reactions such as edema, weight gain, and heart failure exacerbation. Clinically, concomitant use may lead to improved glycemic control but also raises concerns for dose-dependent toxicities, necessitating careful monitoring and possible dose adjustment of pioglitazone."
Explore head-to-head clinical comparisons of other medications in the same therapeutic classes.
Common clinical questions about COMPOUND 65 vs IBU, answered by our medical review team.
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).. IBU is a Nonsteroidal Anti-inflammatory Drug (NSAID) that works by Non-selective inhibitor of cyclooxygenase (COX-1 and COX-2), decreasing prostaglandin synthesis, thereby reducing inflammation, pain, and fever.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between COMPOUND 65 and IBU 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 COMPOUND 65 is: 25 mg orally every 8 hours as needed for pain; maximum 75 mg per day.. The standard adult dose of IBU is: 200-800 mg orally every 6-8 hours as needed; maximum 3200 mg/day. For OTC use: 200-400 mg every 4-6 hours; max 1200 mg/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 COMPOUND 65 and IBU 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. 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. IBU is classified as Category C. First and second trimester: Increased risk of miscarriage and congenital malformations (particularly cardiac defects) associated with NSAID use. Third trimester: Known risk of prem. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.