Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
COMBUNOX vs COMBOGESIC IV
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
COMBUNOX is a fixed-dose combination of oxycodone, a full mu-opioid receptor agonist, and ibuprofen, a nonsteroidal anti-inflammatory drug (NSAID) that inhibits cyclooxygenase (COX-1 and COX-2), thereby reducing prostaglandin synthesis.
Combination of acetaminophen (paracetamol) and ibuprofen. Acetaminophen: Weak COX inhibition in CNS, analgesic and antipyretic. Ibuprofen: Non-selective COX-1/COX-2 inhibition, anti-inflammatory, analgesic, antipyretic.
FDA-approved: Short-term (up to 7 days) management of acute pain severe enough to require an opioid analgesic and for which alternative treatments are inadequate.,Off-label: None commonly recognized.
Management of mild to moderate pain,Reduction of fever (acetaminophen component),Off-label: Acute pain relief in various settings
1 tablet (ibuprofen 400 mg/oxycodone HCl 10 mg) orally every 4 to 6 hours as needed for pain; maximum 4 tablets per day.
1 vial (1000 mg paracetamol + 60 mg codeine phosphate) IV infusion over 15 minutes, every 4-6 hours as needed, max 4 vials per day.
Oxycodone terminal half-life is 3.5-5.5 hours (mean ~3.8 hours) in immediate-release form; controlled-release formulations have a prolonged absorption phase with an effective half-life of 4.5-8 hours. Ibuprofen terminal half-life is 1.8-2.5 hours (mean ~2 hours). Clinical context: Oxycodone's half-life supports dosing every 4-6 hours (IR) or 12 hours (CR); ibuprofen's short half-life requires frequent dosing for sustained anti-inflammatory effect. In elderly or hepatic impairment, oxycodone half-life may increase to 6-8 hours; ibuprofen half-life may be slightly prolonged.
Paracetamol: 1.5-3 hours; tramadol: 6 hours (active metabolite M1: 7-9 hours). Clinical context: Extended half-life in hepatic impairment (cirrhosis) and elderly; requires dose adjustment.
Oxycodone: Primarily hepatic via CYP3A4 and CYP2D6 to active and inactive metabolites. Ibuprofen: Hepatic via CYP2C9 to inactive metabolites; also undergoes glucuronidation.
Acetaminophen: Hepatic via conjugation (glucuronidation, sulfation) and CYP2E1 (minor) to reactive metabolite NAPQI. Ibuprofen: Hepatic via CYP2C9 and CYP2C8 to inactive metabolites.
Oxycodone is primarily metabolized in the liver; metabolites are excreted mainly in urine. Approximately 87% of an oral dose is eliminated within 24 hours: 60-70% as oxycodone metabolites (mostly noroxycodone and oxymorphone conjugates) and 10-15% as unchanged oxycodone. Ibuprofen is rapidly metabolized and excreted; about 90% of a dose is eliminated in urine as metabolites (primarily hydroxylated and carboxylated forms) and <1% as unchanged drug. Biliary/fecal elimination accounts for <10% of each component.
Renal: 90% as glucuronide conjugates and unchanged drug for paracetamol; biliary: 10% for paracetamol. For tramadol: renal 90% (unchanged and metabolites), fecal 10%.
Oxycodone: ~45% bound primarily to albumin. Ibuprofen: >99% bound to albumin. No displacement interactions likely at therapeutic concentrations.
Paracetamol: 10-25% bound to albumin; tramadol: 20% bound to albumin; active metabolite M1: negligible binding.
Oxycodone: Vd of 2.0-3.0 L/kg (mean ~2.6 L/kg), indicating extensive tissue distribution. Ibuprofen: Vd of 0.1-0.2 L/kg (mean ~0.15 L/kg), confined to plasma and extracellular fluid. Combined formulation Vd not significantly altered.
Paracetamol: 0.9 L/kg; tramadol: 2.7 L/kg (wide distribution into tissues). Clinical meaning: High Vd for tramadol indicates extensive tissue distribution.
Oral bioavailability of oxycodone: 60-87% (mean ~75%) with first-pass metabolism accounting for ~25% loss. Ibuprofen: >80% (mean ~95%) with minimal first-pass effect. Food reduces rate but not extent of absorption; taking with food may delay peak concentrations by 1-2 hours.
IV: 100% for both components. Oral: Paracetamol 85-90%; tramadol 75% (first-pass metabolism). Not applicable for IM/SC routes.
GFR 30-89 m L/min: No adjustment needed. GFR <30 m L/min: Avoid use due to ibuprofen component. Hemodialysis: Not recommended.
e GFR 30-50 m L/min: administer every 6 hours; e GFR <30 m L/min: not recommended; dialysis: contraindicated.
Child-Pugh A: No adjustment. Child-Pugh B: Reduce oxycodone dose by 50% (e.g., consider alternative). Child-Pugh C: Avoid use (contraindicated).
Child-Pugh A: no adjustment; Child-Pugh B: reduce dose by 50% or extend interval; Child-Pugh C: contraindicated.
Not approved for pediatric use; safety and efficacy not established in patients <18 years.
Children >12 years and ≥50 kg: same as adult dose; <12 years or <50 kg: not recommended due to codeine; use alternative analgesic.
Initiate at lower dose (e.g., 1 tablet of ibuprofen 200 mg/oxycodone HCl 5 mg) every 6 hours as needed; monitor for CNS depression and renal function. Maximum 4 tablets per day.
Initiate at lowest effective dose; monitor for respiratory depression and hypotension; consider reduced dose or extended interval due to age-related clearance decline.
Addiction, abuse, and misuse; life-threatening respiratory depression; accidental ingestion; neonatal opioid withdrawal syndrome; risks from concomitant use with benzodiazepines or other CNS depressants; risk of serious cardiovascular and gastrointestinal events with NSAIDs.
Risk of severe hepatic injury with acetaminophen; do not exceed maximum daily dose (4 g/day).
Respiratory depression; addiction potential; CNS depression; hepatotoxicity; renal toxicity; gastrointestinal bleeding; cardiovascular thrombotic events; anaphylactic reactions; drug interactions with CYP3A4 inhibitors/inducers; avoid in severe hepatic impairment.
Hepatotoxicity (acetaminophen overdose), GI bleeding/ulceration (ibuprofen), renal impairment, cardiovascular thrombotic events (ibuprofen), anaphylactic reactions, masking of infection signs.
Significant respiratory depression; acute or severe bronchial asthma; paralytic ileus; known hypersensitivity to oxycodone, ibuprofen, or any component; patients with gastrointestinal bleeding or perforation; advanced renal disease; coronary artery bypass graft (CABG) surgery perioperative pain; use of MAO inhibitors within 14 days.
Hypersensitivity to any component, active GI bleeding, severe hepatic impairment, severe renal impairment (Cr Cl <30 m L/min), history of asthma/urticaria with NSAIDs, perioperative pain in CABG surgery.
Avoid alcohol. Taking with food decreases GI irritation. Grapefruit juice may increase oxycodone levels; limit intake. High-fat meals can delay but not reduce oxycodone absorption.
Concurrent food intake does not affect IV administration. However, patients should avoid alcohol consumption due to increased risk of hepatotoxicity from paracetamol and gastrointestinal bleeding from ibuprofen. No other specific food interactions are known.
COMBUNOX (oxycodone/ibuprofen) is pregnancy category C prior to 30 weeks and category D after 30 weeks. First trimester: limited data, potential neural tube defects with NSAIDs; second trimester: NSAID use associated with fetal renal dysfunction and oligohydramnios; third trimester: NSAIDs may cause premature closure of ductus arteriosus, pulmonary hypertension, and oligohydramnios; oxycodone may lead to neonatal opioid withdrawal syndrome (NOWS) with chronic use.
First trimester: Avoid combination acetaminophen/NSAIDs due to potential cardiovascular and neural tube defects with NSAIDs; acetaminophen considered relatively safe but limit use. Second trimester: NSAIDs associated with oligohydramnios and fetal renal effects; acetaminophen safe at therapeutic doses. Third trimester: NSAIDs contraindicated due to risk of premature ductus arteriosus closure, oligohydramnios, and neonatal renal impairment; acetaminophen preferred.
Oxycodone excreted in breast milk; M/P ratio approximately 3.6:1. Ibuprofen minimal transfer (M/P ~0.01). Relative infant dose (RID) for oxycodone ~3.5% of maternal weight-adjusted dose; ibuprofen <0.1%. Potential for infant sedation, respiratory depression, and withdrawal. Use caution; avoid if mother is a CYP2D6 ultra-rapid metabolizer. American Academy of Pediatrics recommends use with monitoring.
Acetaminophen: Low transfer into breast milk, M/P ratio 0.91-1.42; considered compatible with breastfeeding. Ibuprofen (if applicable, assuming NSAID component): M/P ratio 0.01-0.06, very low levels; considered compatible. Avoid NSAIDs if infant has thrombocytopenia or renal impairment. Monitor infant for rash, drowsiness, or gastrointestinal effects.
No specific dose adjustment for pregnancy is established. However, increased renal clearance in pregnancy may reduce ibuprofen levels; clinical significance unknown. Oxycodone pharmacokinetics altered: increased volume of distribution and clearance may require higher doses for analgesia. Use lowest effective dose and shortest duration. Avoid prolonged use >48 hours near term due to risk of premature ductus closure.
Acetaminophen: No dose adjustment needed; use lowest effective dose. NSAID component: Avoid in third trimester; if necessary in earlier trimesters, use lowest effective dose for shortest duration. Pharmacokinetic changes (increased plasma volume, enhanced clearance) may require higher acetaminophen dosing but not standardly adjusted; monitor effect.
Combunox contains ibuprofen 400 mg and oxycodone 5 mg. The fixed-dose combination limits flexibility; use only when both components are needed. Monitor for GI bleeding, renal impairment, and opioid-related respiratory depression. Avoid in patients with severe asthma, NSAID allergy, or opioid intolerance. Watch for drug interactions with anticoagulants, SSRIs, and CYP3A4 inhibitors/inducers. The combination increases risk of serotonin syndrome if used with other serotonergic drugs.
COMBOGESIC IV is a fixed-dose combination of paracetamol (acetaminophen) 1000 mg and ibuprofen 300 mg per 100 m L solution. Administer only as a single intravenous infusion over 15 minutes. Do not administer if the solution contains particulates or is discolored. Avoid use in patients with severe hepatic impairment (Child-Pugh C), severe renal impairment (e GFR <30 m L/min/1.73m²), active peptic ulcer disease, or history of aspirin allergy. Monitor for signs of hepatotoxicity (paracetamol) and renal toxicity (ibuprofen). Contraindicated in patients with severe heart failure (NYHA III/IV) or preoperative CABG surgery. Use lowest effective dose for shortest duration. Not recommended for patients <18 years due to lack of safety data. Contains ibuprofen; risk of serious GI adverse events including bleeding, ulceration, and perforation, especially in elderly. Do not exceed 4 doses (4000 mg paracetamol/1200 mg ibuprofen) per day. Concomitant use of other NSAIDs or paracetamol-containing products is contraindicated.
Take with food or milk to reduce stomach upset.,Do not exceed prescribed dose; can cause liver damage, stomach bleeding, or addiction.,Avoid alcohol while taking this medication.,May cause dizziness or drowsiness; do not drive until you know how it affects you.,Report sudden stomach pain, black stool, or vomiting blood.,Stop use and seek emergency care if signs of allergic reaction (rash, difficulty breathing) occur.,Do not combine with other NSAIDs or acetaminophen without consulting provider.,Store securely to prevent accidental overdose or misuse.
This medication is given intravenously and is not for self-administration.,Inform your healthcare provider if you have a history of liver or kidney disease, stomach ulcers, bleeding disorders, heart disease, high blood pressure, or asthma.,Avoid taking any additional acetaminophen (paracetamol) or NSAIDs (e.g., ibuprofen, naproxen) while receiving this medication.,Report any signs of allergic reaction (rash, itching, swelling, difficulty breathing), stomach pain, black or bloody stools, vomiting blood, unusual bruising or bleeding, yellowing of skin or eyes, dark urine, or severe fatigue.,Do not consume alcohol while being treated with this medication; alcohol increases the risk of liver damage and stomach bleeding.,This medication may cause dizziness or drowsiness; avoid driving or operating machinery if affected.,Tell your doctor about all medications you are taking, including prescription, over-the-counter, and herbal products, especially blood thinners (warfarin, aspirin), diuretics, lithium, methotrexate, and ACE inhibitors.,If you are pregnant, planning to become pregnant, or breastfeeding, discuss the risks with your healthcare provider.
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 COMBUNOX vs COMBOGESIC IV, answered by our medical review team.
COMBUNOX is a Analgesic Combination (Opioid + NSAID) that works by COMBUNOX is a fixed-dose combination of oxycodone, a full mu-opioid receptor agonist, and ibuprofen, a nonsteroidal anti-inflammatory drug (NSAID) that inhibits cyclooxygenase (COX-1 and COX-2), thereby reducing prostaglandin synthesis.. COMBOGESIC IV is a Analgesic Combination (Opioid + Non-Opioid) that works by Combination of acetaminophen (paracetamol) and ibuprofen. Acetaminophen: Weak COX inhibition in CNS, analgesic and antipyretic. Ibuprofen: Non-selective COX-1/COX-2 inhibition, anti-inflammatory, analgesic, antipyretic.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between COMBUNOX and COMBOGESIC IV 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 COMBUNOX is: 1 tablet (ibuprofen 400 mg/oxycodone HCl 10 mg) orally every 4 to 6 hours as needed for pain; maximum 4 tablets per day.. The standard adult dose of COMBOGESIC IV is: 1 vial (1000 mg paracetamol + 60 mg codeine phosphate) IV infusion over 15 minutes, every 4-6 hours as needed, max 4 vials 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 COMBUNOX and COMBOGESIC IV 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. COMBUNOX is classified as Category C. COMBUNOX (oxycodone/ibuprofen) is pregnancy category C prior to 30 weeks and category D after 30 weeks. First trimester: limited data, potential neural tube defects with NSAIDs; se. COMBOGESIC IV is classified as Category C. First trimester: Avoid combination acetaminophen/NSAIDs due to potential cardiovascular and neural tube defects with NSAIDs; acetaminophen considered relatively safe but limit use.. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.