Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
ACETAMINOPHEN, ASPIRIN, AND CODEINE PHOSPHATE vs ACETAMINOPHEN AND HYDROCODONE BITARTRATE
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: June 2026 · OpiCalc Medical Review Team
Acetaminophen: cyclooxygenase (COX) inhibitor, primarily central, analgesic and antipyretic. Aspirin: irreversible COX-1 and COX-2 inhibitor, analgesic, anti-inflammatory, antipyretic, antiplatelet. Codeine: prodrug converted to morphine; mu-opioid receptor agonist.
Acetaminophen: analgesic and antipyretic effects via inhibition of cyclooxygenase (COX) and activation of descending serotonergic pathways; central action. Hydrocodone: mu-opioid receptor agonist; activates G-protein coupled receptors to modulate pain perception and emotional response.
Mild to moderate pain,Fever (acetaminophen and aspirin),Inflammatory conditions (aspirin)
Moderate to moderately severe pain,Cough suppression (hydrocodone; off-label)
1-2 tablets (each containing acetaminophen 300 mg, aspirin 300 mg, codeine phosphate 30 mg) orally every 4-6 hours as needed for pain; maximum 8 tablets/day.
1-2 tablets (containing 5-10 mg hydrocodone and 300-325 mg acetaminophen) orally every 4-6 hours as needed for pain; maximum 8 tablets per day.
Acetaminophen: 2-3 hours (terminal). Aspirin: 15-30 minutes (parent drug); salicylate: 2-3 hours at low doses, 15-30 hours at high doses due to saturable metabolism. Codeine: 2.5-4 hours. Clinical context: Prolonged half-life of salicylate at high doses increases risk of toxicity; hepatic impairment prolongs acetaminophen and codeine half-lives.
Acetaminophen: 2-3 hours in adults; prolonged in hepatic impairment (up to 5 hours). Hydrocodone: 3.8-4.5 hours (range 3-5 hours) in healthy adults; prolonged in elderly or hepatic/renal impairment. Clinical context: repeated dosing may require extended intervals in renal impairment.
Acetaminophen: hepatic via CYP2E1, CYP1A2, CYP3A4; glucuronidation and sulfation; NAPQI formation. Aspirin: hepatic hydrolysis to salicylate; conjugation with glycine and glucuronic acid. Codeine: hepatic via CYP2D6 to morphine (active); also via CYP3A4 to norcodeine.
Acetaminophen: primarily via glucuronidation (UGT1A1, UGT1A6, UGT1A9) and sulfation; minor CYP2E1 oxidation to NAPQI (toxic metabolite). Hydrocodone: CYP3A4 and CYP2D6; N-demethylation to norhydrocodone; O-demethylation to hydromorphone (CYP2D6).
Acetaminophen: renal excretion of metabolites (glucuronide and sulfate conjugates, ~85-90%), minor parent drug (<5%). Aspirin: renal excretion of salicylate and its metabolites (salicyluric acid, glucuronides, gentisic acid), dose-dependent; at therapeutic doses, ~50-80% as free salicylate and conjugates. Codeine: renal excretion of free and conjugated codeine (about 90%) and metabolites (morphine, norcodeine).
Acetaminophen: primarily renal excretion of conjugated metabolites (glucuronide and sulfate) with approximately 5% excreted unchanged. Hydrocodone: renal excretion as unchanged drug and metabolites (O-demethylated and N-demethylated); total renal excretion accounts for about 60-70% of dose (parent and metabolites). Biliary/fecal elimination is minimal.
Acetaminophen: 10-25% (albumin). Aspirin: 50-80% (albumin), dose-dependent; salicylate: 75-90% (albumin). Codeine: ~7% (albumin).
Acetaminophen: 10-25% bound, nonspecific binding to albumin. Hydrocodone: 25-50% bound, primarily to albumin and alpha-1-acid glycoprotein.
Acetaminophen: 0.9-1.0 L/kg (large distribution including liver). Aspirin: 0.15-0.2 L/kg (low Vd, confined to plasma and extracellular fluid); salicylate: 0.2-0.3 L/kg. Codeine: 3-6 L/kg (extensive tissue distribution). Clinical meaning: Large Vd for codeine suggests extensive tissue binding; aspirin Vd is small, consistent with limited extravascular distribution.
Acetaminophen: 0.8-1.0 L/kg, indicating distribution into total body water; clinically relevant for loading dose calculations. Hydrocodone: 3.0-4.0 L/kg, suggesting extensive tissue distribution; higher Vd may require higher loading doses but has no clinical target.
Oral: Acetaminophen: 85-95%. Aspirin: 40-60% (due to first-pass hydrolysis to salicylate). Codeine: ~50% due to first-pass metabolism.
Acetaminophen: oral bioavailability 85-95% (first-pass metabolism minimal). Hydrocodone: oral bioavailability about 25-45% due to first-pass hepatic metabolism; significant interindividual variability.
GFR 30-59 m L/min: Administer every 6 hours; maximum 6 tablets/day. GFR 15-29 m L/min: Administer every 12 hours; maximum 4 tablets/day. GFR <15 m L/min: Not recommended due to accumulation of codeine metabolites.
GFR 10-50 m L/min: administer every 6 hours; GFR <10 m L/min: administer every 8 hours; avoid in severe impairment due to acetaminophen metabolite accumulation.
Child-Pugh Class A: No adjustment. Child-Pugh Class B: Reduce dose by 50% and extend interval to every 6 hours; maximum 4 tablets/day. Child-Pugh Class C: Contraindicated.
Child-Pugh A: no adjustment; Child-Pugh B: reduce dose by 50% or extend interval; Child-Pugh C: use with caution, avoid if possible, consider alternative therapy.
Not recommended for children <12 years due to aspirin risk of Reye syndrome. For children ≥12 years: Dose based on codeine component (0.5-1 mg/kg/dose) with maximum acetaminophen 75 mg/kg/day and aspirin 100 mg/kg/day. Typical: 1 tablet (acetaminophen 300 mg/aspirin 300 mg/codeine 30 mg) every 4-6 hours as needed; max 4 tablets/day.
Dosing based on hydrocodone component: 0.1-0.2 mg/kg/dose every 4-6 hours; maximum daily acetaminophen limit: 75 mg/kg/day; not recommended for children <2 years.
Start with lowest effective dose (e.g., 1 tablet every 6 hours); monitor renal and hepatic function; maximum 6 tablets/day due to increased sensitivity and risk of adverse effects.
Initiate at lowest effective dose, typically 1 tablet (2.5-5 mg hydrocodone) every 6 hours; monitor for respiratory depression and acetaminophen toxicity; avoid in frail elderly with hepatic impairment.
Risk of medication errors: confusion between different strengths and concentrations of acetaminophen can result in accidental overdose and fatal hepatotoxicity. Aspirin use in children and teenagers with viral infections is associated with Reye's syndrome.
Addiction, abuse, and misuse; life-threatening respiratory depression; accidental ingestion of acetaminophen; neonatal opioid withdrawal syndrome; interaction with alcohol; risk of medication errors.
Hepatotoxicity (acetaminophen dose >4 g/day), Reye's syndrome (aspirin in children), respiratory depression (codeine), tolerance/dependence, bleeding risk (aspirin), GI toxicity, renal impairment, hypersensitivity reactions.
Hepatotoxicity from acetaminophen overdose; respiratory depression; increased intracranial pressure; CNS depression; elderly/debilitated patients; renal impairment; opioid-induced hyperalgesia; serotonin syndrome; interaction with CNS depressants; risk of adrenal insufficiency; severe hypotension; use in patients with gastrointestinal obstruction; convulsion risk; severe hepatic impairment; urinary retention; acute abdominal conditions; hypothyroidism; prostatic hypertrophy; adrenocortical insufficiency; pregnancy/lactation; pediatric use; geriatric use; renal impairment; hepatic impairment.
Hypersensitivity to any component, active peptic ulcer disease, bleeding disorders, severe hepatic impairment, severe respiratory depression, children with viral illness (aspirin), pregnancy (third trimester for aspirin, codeine cautious).
Hypersensitivity to acetaminophen or hydrocodone; significant respiratory depression; acute or severe bronchial asthma; upper airway obstruction; known or suspected gastrointestinal obstruction; paralytic ileus; concomitant use of monoamine oxidase inhibitors (MAOIs) or within 14 days; severe hepatic impairment (acetaminophen toxicity risk); acute alcoholism.
Avoid alcohol due to increased risk of acetaminophen hepatotoxicity and aspirin-induced GI bleeding. Avoid large amounts of caffeine or high-tyramine foods (e.g., aged cheeses, cured meats) as they may affect CYP2D6 metabolism of codeine.
Avoid alcohol consumption during therapy; ethanol increases acetaminophen hepatotoxicity risk and enhances CNS depression. Grapefruit juice may inhibit CYP2D6 (minor effect) but no significant clinical interaction. No other specific food restrictions.
Acetaminophen: Generally considered low risk; association with ASD and ADHD with prolonged use not fully established. Aspirin: First trimester: possible increased risk of gastroschisis; second trimester: relatively safe; third trimester: risk of premature closure of ductus arteriosus, oligohydramnios, and increased peripartum hemorrhage. Codeine: First trimester: possible neural tube defects; second and third trimesters: risk of respiratory depression, withdrawal in neonate with chronic use; neonatal opioid withdrawal syndrome (NOWS) possible.
First trimester: Acetaminophen considered low risk; hydrocodone is a pregnancy category C drug. Data from retrospective studies suggest a small increased risk of certain congenital malformations (e.g., neural tube defects, cleft palate) with first trimester opioid use, but absolute risk is low. Second trimester: Low risk as above. Third trimester: Prolonged use of hydrocodone can cause neonatal opioid withdrawal syndrome (NOWS); acetaminophen is safe. Use only if benefit outweighs risk.
Acetaminophen: M/P ratio approximately 0.91-1.42; considered safe. Aspirin: M/P ratio 0.08-0.15; high doses may cause Reye's syndrome; avoid or use low doses. Codeine: M/P ratio about 2.5; variable metabolism; risk of CNS depression in infant; avoid due to potential for toxicity in CYP2D6 ultrarapid metabolizers.
Acetaminophen excretion in breast milk is low (M/P ratio ~0.9). Hydrocodone is excreted in small amounts (M/P ratio ~2.1). The relative infant dose is estimated to be 2.5-3.5% of maternal weight-adjusted dose for hydrocodone. Monitor infant for sedation and respiratory depression. Consider benefit to mother and potential neonatal opioid withdrawal if used chronically.
Acetaminophen: No dose adjustment needed. Aspirin: Avoid in third trimester; use lowest effective dose if necessary. Codeine: Avoid in pregnancy; if used, lowest effective dose for shortest duration; caution for CYP2D6 polymorphism. Pharmacokinetic changes: Increased clearance of codeine during pregnancy may require higher doses but risk outweighs benefit.
During pregnancy, increased plasma volume and enhanced hepatic clearance may reduce serum concentrations of both drugs. However, dosing adjustments are not routinely recommended due to risk of undertreatment. Use the lowest effective dose of hydrocodone for the shortest duration. For acetaminophen, maximum daily dose should not exceed 3000 mg to avoid hepatotoxicity.
Combination analgesic with acetaminophen (hepatotoxic at high doses), aspirin (antiplatelet, GI irritant, contraindicated in children <12 due to Reye's syndrome), and codeine (prodrug to morphine via CYP2D6; efficacy depends on CYP2D6 phenotype; risk of CNS/respiratory depression). Avoid in severe hepatic/renal impairment, active peptic ulcer, bleeding disorders, or concomitant use of other CNS depressants. Maximum acetaminophen dose from all sources: 4 g/day.
Acetaminophen-hydrocodone is contraindicated in severe respiratory depression, acute or severe bronchial asthma, and known hypersensitivity. Monitor for respiratory depression, especially in elderly or debilitated patients. Avoid use with other acetaminophen-containing products to prevent hepatotoxicity. Hydrocodone is a prodrug metabolized by CYP2D6 to hydromorphone; CYP2D6 ultrarapid metabolizers may experience toxicity. Use with caution in patients with head injury, increased intracranial pressure, or severe hepatic impairment. Naloxone is the reversal agent for opioid effects; acetylcysteine for acetaminophen overdose.
Do not exceed recommended dose; acetaminophen overdosage can cause serious liver damage.,Do not take with other products containing acetaminophen or aspirin.,Avoid alcohol while taking this medication to reduce risk of liver toxicity and GI bleeding.,This product contains aspirin; do not give to children/teenagers with chickenpox or flu-like symptoms to avoid Reye's syndrome.,May cause drowsiness; do not drive or operate machinery until you know how you react.,Codeine is a narcotic pain reliever with abuse potential; use exactly as prescribed.,Seek medical attention if you experience signs of allergic reaction (rash, difficulty breathing) or bleeding (black/tarry stools, unusual bruising).
Take exactly as prescribed; do not increase dose or frequency without consulting your doctor.,Avoid alcohol and other CNS depressants (e.g., benzodiazepines, sedatives) as they increase risk of severe drowsiness and respiratory depression.,Do not exceed 4000 mg of acetaminophen per day from all sources; check labels of other medications.,This medication may cause dizziness or drowsiness; avoid driving or operating heavy machinery until you know how it affects you.,Store securely out of reach of others, especially children, as misuse can cause overdose and death.,Do not stop abruptly; withdrawal may occur. Taper under medical supervision.,Contact emergency if you experience trouble breathing, extreme drowsiness, or signs of allergic reaction.,Report any history of substance abuse, as this medication has abuse potential.
"Pirenzepine, a selective M1 muscarinic antagonist, reduces gastrointestinal motility and secretions, while codeine, an opioid agonist, also decreases gastrointestinal motility via mu-opioid receptors. Concurrent use leads to additive anticholinergic and opioid effects, resulting in enhanced risk of severe constipation, paralytic ileus, and central nervous system depression. Clinically, patients may experience exacerbated sedation, respiratory depression, and urinary retention."
"Ropinirole, a non-ergoline dopamine agonist used in Parkinson's disease and restless legs syndrome, may reduce the analgesic efficacy of codeine. This is likely due to pharmacodynamic antagonism at central dopamine and opioid receptors, as well as potential pharmacokinetic interactions that decrease the conversion of codeine to its active metabolite morphine via CYP2D6 inhibition by ropinirole. The resultant blunted opioid response can lead to inadequate pain control, necessitating dose adjustment or alternative therapy."
"Vemurafenib induces CYP3A4, significantly reducing the plasma concentrations of codeine, which is metabolized via CYP3A4 to its active metabolite morphine. This may diminish codeine's analgesic efficacy, potentially leading to inadequate pain control. Additionally, reduced formation of morphine may lower the risk of opioid-related adverse effects."
"Hydrocodone, an opioid agonist, and scopolamine, an anticholinergic agent, both exhibit central nervous system (CNS) depressant effects. When co-administered, their combined activity can lead to additive CNS depression, resulting in enhanced sedation, respiratory depression, and cognitive impairment. This interaction may also increase the risk of constipation and urinary retention due to additive anticholinergic effects from both drugs."
"Pargyline, a monoamine oxidase inhibitor (MAOI), irreversibly inhibits the metabolism of amines, leading to increased intraneuronal stores of norepinephrine. Hydrocodone, a semisynthetic opioid, can release these stored catecholamines, potentially causing a hypertensive crisis, serotonin syndrome, or CNS excitation. Coadministration may also result in excessive sedation and respiratory depression due to additive CNS depressant effects, requiring immediate clinical attention."
"Hydrocodone, an opioid agonist, and oxprenolol, a non-selective beta-adrenoceptor antagonist, are both central nervous system (CNS) depressants. Their combined use can lead to additive CNS depression, resulting in excessive sedation, respiratory depression, hypotension, and bradycardia. This interaction is particularly dangerous in patients with compromised cardiac or respiratory function, potentially leading to coma or death."
Explore head-to-head clinical comparisons of other medications in the same therapeutic classes.
Common clinical questions about ACETAMINOPHEN, ASPIRIN, AND CODEINE PHOSPHATE vs ACETAMINOPHEN AND HYDROCODONE BITARTRATE, answered by our medical review team.
ACETAMINOPHEN, ASPIRIN, AND CODEINE PHOSPHATE is a Opioid Agonist that works by Acetaminophen: cyclooxygenase (COX) inhibitor, primarily central, analgesic and antipyretic. Aspirin: irreversible COX-1 and COX-2 inhibitor, analgesic, anti-inflammatory, antipyretic, antiplatelet. Codeine: prodrug converted to morphine; mu-opioid receptor agonist.. ACETAMINOPHEN AND HYDROCODONE BITARTRATE is a Opioid Agonist that works by Acetaminophen: analgesic and antipyretic effects via inhibition of cyclooxygenase (COX) and activation of descending serotonergic pathways; central action. Hydrocodone: mu-opioid receptor agonist; activates G-protein coupled receptors to modulate pain perception and emotional response.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between ACETAMINOPHEN, ASPIRIN, AND CODEINE PHOSPHATE and ACETAMINOPHEN AND HYDROCODONE BITARTRATE depend on the specific clinical indication. These are both Opioid Agonist agents and are not directly interchangeable by dose. A physician or clinical pharmacist should guide any therapeutic switching decisions.
The standard adult dose of ACETAMINOPHEN, ASPIRIN, AND CODEINE PHOSPHATE is: 1-2 tablets (each containing acetaminophen 300 mg, aspirin 300 mg, codeine phosphate 30 mg) orally every 4-6 hours as needed for pain; maximum 8 tablets/day.. The standard adult dose of ACETAMINOPHEN AND HYDROCODONE BITARTRATE is: 1-2 tablets (containing 5-10 mg hydrocodone and 300-325 mg acetaminophen) orally every 4-6 hours as needed for pain; maximum 8 tablets per day.. Dosing should always be individualized based on indication, renal and hepatic function, age, and other patient factors.
A moderate-severity drug interaction has been identified when combining ACETAMINOPHEN, ASPIRIN, AND CODEINE PHOSPHATE and ACETAMINOPHEN AND HYDROCODONE BITARTRATE. Hydrocodone may increase the central nervous system depressant (CNS depressant) activities of Codeine. Consult your prescriber before combining these medications.
The maternal-fetal safety profiles differ. ACETAMINOPHEN, ASPIRIN, AND CODEINE PHOSPHATE is classified as Category D/X. Acetaminophen: Generally considered low risk; association with ASD and ADHD with prolonged use not fully established. Aspirin: First trimester: possible increased risk of gastrosch. ACETAMINOPHEN AND HYDROCODONE BITARTRATE is classified as Category D/X. First trimester: Acetaminophen considered low risk; hydrocodone is a pregnancy category C drug. Data from retrospective studies suggest a small increased risk of certain congenital. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.