Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
TYLENOL W/ CODEINE NO. 1 vs ACETAMINOPHEN AND HYDROCODONE BITARTRATE
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Codeine is a prodrug that undergoes O-demethylation via CYP2D6 to morphine, which acts as a μ-opioid receptor agonist. Acetaminophen inhibits cyclooxygenase (COX) enzymes in the CNS, reducing prostaglandin synthesis and modulating pain perception.
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,Pyrexia
Moderate to moderately severe pain,Cough suppression (hydrocodone; off-label)
Adult: 1-2 tablets (acetaminophen 300 mg/codeine 8 mg per tablet) orally every 4-6 hours as needed; maximum 8 tablets per day. Route: oral. Frequency: every 4-6 hours.
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; Codeine: 2.5-3.5 hours; Morphine (active metabolite): 2-4 hours. Terminal half-life prolonged in hepatic impairment or elderly.
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 is primarily metabolized via glucuronidation and sulfation in the liver, with a minor pathway via CYP2E1 to a toxic metabolite (NAPQI). Codeine is metabolized via CYP2D6 to morphine, via CYP3A4 to norcodeine, and via glucuronidation.
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).
Renal: ~70-80% of codeine as inactive metabolites (codeine-6-glucuronide, norcodeine, morphine) and ~5-10% as unchanged codeine; ~5-15% of acetaminophen as unchanged drug. Biliary/fecal: minimal (<5% for both).
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% bound to plasma proteins; Codeine: ~25% bound to plasma proteins.
Acetaminophen: 10-25% bound, nonspecific binding to albumin. Hydrocodone: 25-50% bound, primarily to albumin and alpha-1-acid glycoprotein.
Acetaminophen: ~0.9 L/kg (distributes throughout total body water); Codeine: ~3-6 L/kg (extensively distributed into tissues).
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.
Acetaminophen: oral bioavailability ~80-85%; Codeine: oral bioavailability ~60-90% (due to first-pass metabolism to morphine).
Acetaminophen: oral bioavailability 85-95% (first-pass metabolism minimal). Hydrocodone: oral bioavailability about 25-45% due to first-pass hepatic metabolism; significant interindividual variability.
Cr Cl 30-50 m L/min: Administer every 6 hours; Cr Cl <30 m L/min: Avoid due to risk of codeine accumulation and toxicity; hemodialysis: Not recommended.
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 (mild): No adjustment needed; Child-Pugh Class B (moderate): Reduce dose by 50% and extend interval to every 6-8 hours; Child-Pugh Class C (severe): 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.
Weight-based: Codeine not recommended in pediatric patients <12 years due to risk of respiratory depression; for ages 12-18 years: 1 tablet (acetaminophen 300 mg/codeine 8 mg) orally every 4-6 hours as needed; maximum 4 tablets per 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 at lowest effective dose (1 tablet) and monitor for respiratory depression and constipation; consider acetaminophen 300 mg/codeine 8 mg every 6 hours; maximum 4 tablets per day.
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.
WARNING: RISK OF MEDICATION ERRORS; ADDICTION, ABUSE, AND MISUSE; RESPIRATORY DEPRESSION; ACCIDENTAL INGESTION; ULTRA-RAPID METABOLISM OF CODEINE AND OTHER RISK FACTORS FOR LIFE-THREATENING RESPIRATORY DEPRESSION IN CHILDREN; NEONATAL OPIOID WITHDRAWAL SYNDROME; INTERACTION WITH ALCOHOL; RISKS FROM CONCOMITANT USE WITH BENZODIAZEPINES OR OTHER CNS DEPRESSANTS; HEPATOTOXICITY.
Addiction, abuse, and misuse; life-threatening respiratory depression; accidental ingestion of acetaminophen; neonatal opioid withdrawal syndrome; interaction with alcohol; risk of medication errors.
Risk of medication errors (confusion with other products),Addiction, abuse, and misuse,Life-threatening respiratory depression,Accidental ingestion (especially in children),Ultra-rapid metabolism of codeine (CYP2D6 ultra-rapid metabolizers),Neonatal opioid withdrawal syndrome with prolonged use during pregnancy,Hepatotoxicity (acetaminophen overdose),Severe hypotension,Seizures,Adrenal insufficiency,Serotonin syndrome with concomitant serotonergic drugs,Increased risk of severe skin reactions (e.g., SJS/TEN),Interaction with alcohol,Risks from concomitant use with benzodiazepines or other CNS depressants,Impaired mental/physical abilities,Use in children with respiratory conditions,Hepatic or renal impairment
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 codeine, acetaminophen, or any component,Significant respiratory depression,Acute or severe bronchial asthma in an unmonitored setting or without resuscitative equipment,Known or suspected gastrointestinal obstruction, including paralytic ileus,Patients with severe hepatic impairment or acute liver disease,Postoperative pain management in children who have had tonsillectomy and/or adenoidectomy,Concurrent use of monoamine oxidase inhibitors (MAOIs) or within 14 days of such therapy
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; may increase risk of hepatotoxicity and CNS depression. No specific food restrictions. May be taken with food to reduce gastrointestinal upset.
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: Low teratogenic risk; use at therapeutic doses not associated with increased major malformations. Codeine: First trimester: Risk of malformations unclear; some studies suggest small increased risk of respiratory defects and spina bifida. Third trimester: Prolonged use may cause neonatal opioid withdrawal syndrome (NOWS); high doses near term may cause neonatal respiratory depression. Avoid chronic high doses.
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: Compatible; low levels in breast milk (M/P ratio ~0.91). Codeine: Excreted into breast milk; M/P ratio ~2.5. Risk of infant opioid toxicity, especially in ultra-rapid CYP2D6 metabolizers. Use lowest effective dose for shortest duration. Monitor infant for drowsiness, feeding difficulties, respiratory depression.
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.
No standard dose adjustment required for acetaminophen. Codeine: Increased clearance in pregnancy may require dose adjustment; however, use lowest effective dose due to unpredictable metabolism. Avoid codeine in pregnancy if possible. Maximum recommended dose: acetaminophen 3000 mg/day; codeine 60 mg/day.
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.
Contains 300 mg acetaminophen and 15 mg codeine per tablet. Maximum acetaminophen dose 4000 mg/day; avoid combination with other acetaminophen products. Codeine is a prodrug requiring CYP2D6 conversion to morphine; poor metabolizers have reduced analgesia, ultra-rapid metabolizers risk toxicity. Monitor for respiratory depression, especially in children, elderly, or obese. Not recommended in breastfeeding mothers due to risk of infant toxicity.
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 13 tablets per 24 hours due to acetaminophen limit.,Avoid alcohol while taking this medication.,Do not use with any other products containing acetaminophen or codeine.,May cause drowsiness; avoid driving or operating machinery.,Store out of reach of children and dispose of unused medication properly.,Seek medical help if you experience difficulty breathing, severe drowsiness, or signs of allergic reaction.
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 TYLENOL W/ CODEINE NO. 1 vs ACETAMINOPHEN AND HYDROCODONE BITARTRATE, answered by our medical review team.
TYLENOL W/ CODEINE NO. 1 is a Opioid Agonist that works by Codeine is a prodrug that undergoes O-demethylation via CYP2D6 to morphine, which acts as a μ-opioid receptor agonist. Acetaminophen inhibits cyclooxygenase (COX) enzymes in the CNS, reducing prostaglandin synthesis and modulating pain perception.. 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 TYLENOL W/ CODEINE NO. 1 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 TYLENOL W/ CODEINE NO. 1 is: Adult: 1-2 tablets (acetaminophen 300 mg/codeine 8 mg per tablet) orally every 4-6 hours as needed; maximum 8 tablets per day. Route: oral. Frequency: every 4-6 hours.. 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 TYLENOL W/ CODEINE NO. 1 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. TYLENOL W/ CODEINE NO. 1 is classified as Category D/X. Acetaminophen: Low teratogenic risk; use at therapeutic doses not associated with increased major malformations. Codeine: First trimester: Risk of malformations unclear; some studi. 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.