Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
COMBOGESIC IV vs A/T/S
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
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.
A/T/S (erythromycin) is a macrolide antibiotic that acts by binding to the 50S ribosomal subunit of susceptible bacteria, inhibiting protein synthesis and bacterial growth.
Management of mild to moderate pain,Reduction of fever (acetaminophen component),Off-label: Acute pain relief in various settings
Treatment of acne vulgaris (FDA-approved indication),Treatment of bacterial infections caused by susceptible organisms (off-label use for acne is the primary use)
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 is individualized based on antithrombin activity level. For acute thrombotic events: initial bolus of 30-50 IU/kg followed by maintenance dosing to achieve target activity levels (80-120% of normal). Prophylaxis: 40-60 IU/kg every 24 hours.
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.
Terminal elimination half-life: 1–2 hours (prolonged in hepatic impairment).
Acetaminophen: Hepatic via conjugation (glucuronidation, sulfation) and CYP2E1 (minor) to reactive metabolite NAPQI. Ibuprofen: Hepatic via CYP2C9 and CYP2C8 to inactive metabolites.
Antithrombin is a glycoprotein; its metabolism involves cellular uptake and catabolism, but specific CYP450 enzymes are not involved. Degradation occurs via proteolysis and reticuloendothelial system clearance.
Renal: 90% as glucuronide conjugates and unchanged drug for paracetamol; biliary: 10% for paracetamol. For tramadol: renal 90% (unchanged and metabolites), fecal 10%.
Renal: 10-20% (active drug and metabolites); Fecal: minimal; Biliary: not significant.
Paracetamol: 10-25% bound to albumin; tramadol: 20% bound to albumin; active metabolite M1: negligible binding.
70-90% bound to serum albumin.
Paracetamol: 0.9 L/kg; tramadol: 2.7 L/kg (wide distribution into tissues). Clinical meaning: High Vd for tramadol indicates extensive tissue distribution.
0.5–0.8 L/kg (low Vd, minimal tissue penetration).
IV: 100% for both components. Oral: Paracetamol 85-90%; tramadol 75% (first-pass metabolism). Not applicable for IM/SC routes.
Topical: 1–5% (minimal systemic absorption).
e GFR 30-50 m L/min: administer every 6 hours; e GFR <30 m L/min: not recommended; dialysis: contraindicated.
No specific adjustment required; drug is not renally eliminated.
Child-Pugh A: no adjustment; Child-Pugh B: reduce dose by 50% or extend interval; Child-Pugh C: contraindicated.
No specific adjustment; antithrombin is produced in the liver, but exogenous replacement does not require dose adjustment in hepatic impairment.
Children >12 years and ≥50 kg: same as adult dose; <12 years or <50 kg: not recommended due to codeine; use alternative analgesic.
Dosing based on weight and antithrombin levels; typical initial dose 30-50 IU/kg, followed by maintenance to achieve target levels. Clinical trial data limited in neonates.
Initiate at lowest effective dose; monitor for respiratory depression and hypotension; consider reduced dose or extended interval due to age-related clearance decline.
No specific adjustment; use standard dosing with monitoring of antithrombin activity and bleeding risk.
Risk of severe hepatic injury with acetaminophen; do not exceed maximum daily dose (4 g/day).
None.
Hepatotoxicity (acetaminophen overdose), GI bleeding/ulceration (ibuprofen), renal impairment, cardiovascular thrombotic events (ibuprofen), anaphylactic reactions, masking of infection signs.
Hypersensitivity reactions including anaphylaxis have occurred.,Prolonged use may result in overgrowth of nonsusceptible organisms including fungi.,Use with caution in patients with hepatic impairment.,Potential for QT prolongation and ventricular arrhythmias, especially with intravenous administration or concomitant drugs that prolong QT interval.
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.
Hypersensitivity to erythromycin or any macrolide antibiotic.,Use with caution in patients with pre-existing QT prolongation or electrolyte abnormalities (relative contraindication).
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.
No specific food interactions. Avoid excessive alcohol consumption as it may increase skin dryness.
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.
FDA Pregnancy Category B. No evidence of teratogenicity in animal studies; no adequate human studies in first trimester. Topical erythromycin has minimal systemic absorption; risk to fetus is low across all trimesters.
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.
Compatible with breastfeeding. Erythromycin is excreted into breast milk in small amounts (M/P ratio approximately 0.5). Topical use results in negligible systemic exposure; unlikely to cause adverse effects in nursing infants.
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.
No dose adjustment required. Systemic absorption from topical application is minimal and not significantly altered by pregnancy-related pharmacokinetic changes.
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.
A/T/S (erythromycin 2% topical solution) is indicated for acne vulgaris. Avoid contact with eyes, mouth, and mucous membranes. May cause skin dryness or irritation; use moisturizer. Effectiveness may decrease with prolonged use due to bacterial resistance. Not recommended for use with other topical erythromycin products or clindamycin to avoid antagonism.
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.
Apply a thin layer to affected areas twice daily after washing.,Avoid contact with eyes, lips, and mouth; if contact occurs, rinse thoroughly with water.,May cause stinging, burning, or peeling; if irritation persists, consult your doctor.,Use sunscreen daily as this medication may increase sensitivity to sunlight.,Do not use more than prescribed; overuse may increase side effects without improving results.,Inform your doctor if you are pregnant, planning to become pregnant, or breastfeeding.,Keep away from open flames or heat sources; product is flammable.
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 COMBOGESIC IV vs A/T/S, answered by our medical review team.
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.. A/T/S is a Macrolide antibiotic that works by A/T/S (erythromycin) is a macrolide antibiotic that acts by binding to the 50S ribosomal subunit of susceptible bacteria, inhibiting protein synthesis and bacterial growth.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between COMBOGESIC IV and A/T/S 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 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.. The standard adult dose of A/T/S is: Dosing is individualized based on antithrombin activity level. For acute thrombotic events: initial bolus of 30-50 IU/kg followed by maintenance dosing to achieve target activity levels (80-120% of normal). Prophylaxis: 40-60 IU/kg every 24 hours.. 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 COMBOGESIC IV and A/T/S 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. 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.. A/T/S is classified as Category C. FDA Pregnancy Category B. No evidence of teratogenicity in animal studies; no adequate human studies in first trimester. Topical erythromycin has minimal systemic absorption; risk . Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.