Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
HYDROCODONE BITARTRATE AND HOMATROPINE METHYLBROMIDE vs TYLENOL W/ CODEINE NO. 3
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: June 2026 · OpiCalc Medical Review Team
Hydrocodone is a semisynthetic opioid agonist that binds to mu-opioid receptors in the CNS, inhibiting ascending pain pathways and altering pain perception. Homatropine methylbromide is an anticholinergic agent that reduces gastrointestinal motility and secretions.
Codeine is a prodrug converted to morphine, which acts as a mu-opioid receptor agonist; acetaminophen inhibits cyclooxygenase (COX) and modulates cannabinoid and serotonergic pathways, with central analgesic effect.
Management of moderate to moderately severe pain where an antitussive effect is desired (hydrocodone component),Off-label: symptomatic relief of irritable bowel syndrome (homatropine methylbromide anticholinergic effect)
Relief of mild to moderately severe pain
Oral: 5 mg hydrocodone/1.5 mg homatropine every 4 to 6 hours as needed; maximum 30 mg hydrocodone per day.
1-2 tablets (300 mg acetaminophen/30 mg codeine per tablet) orally every 4 hours as needed for pain; maximum 12 tablets per day.
The terminal elimination half-life of hydrocodone is approximately 3.8-4.5 hours in adults, though it may be prolonged in hepatic impairment or elderly patients. Homatropine methylbromide has a half-life of about 2-3 hours.
Acetaminophen: 2-3 hours (prolonged in hepatic or renal impairment, overdose). Codeine: 2.5-3.5 hours; morphine from codeine: approx 2 hours; prolonged in hepatic or renal impairment.
GFR 30-89 m L/min: No adjustment. GFR 10-29 m L/min: Reduce dose by 25-50% or extend interval. GFR <10 m L/min: Reduce dose by 50% or extend interval to every 8-12 hours.
GFR 10-50 m L/min: administer 75% of normal dose every 6 hours; GFR <10 m L/min: administer 50% of normal dose every 6 hours. Codeine is not recommended in severe renal impairment due to risk of toxicity.
Addiction, abuse, and misuse; life-threatening respiratory depression; accidental ingestion; neonatal opioid withdrawal syndrome; risks from concomitant use with benzodiazepines or other CNS depressants.
First trimester: Limited data; hydrocodone is not a major teratogen but opioid use may be associated with neural tube defects (RR 1.5-2.0) based on some studies. Homatropine methylbromide: No adequate studies; anticholinergics may be associated with minor malformations. Second trimester: No specific structural risks identified. Third trimester: Chronic use may cause neonatal opioid withdrawal syndrome (NOWS); anticholinergic effects may cause neonatal ileus or urinary retention.
Acetaminophen: Generally considered low risk; no consistent evidence of major malformations. Codeine: First trimester: risk of neural tube defects, cleft palate; second trimester: no specific major risks; third trimester: risk of neonatal respiratory depression, withdrawal syndrome if chronic use. Codeine is metabolized to morphine, which may cause fetal dependence.
Hydrocodone bitartrate is an opioid agonist; homatropine methylbromide is an anticholinergic. The combination is used for cough suppression. Caution in patients with respiratory depression, COPD, or asthma. Monitor for CNS depression and constipation. The anticholinergic component may cause dry mouth, urinary retention, and blurred vision. Avoid use in patients with narrow-angle glaucoma or gastrointestinal obstruction. The recommended dose is one tablet every 4-6 hours; do not exceed 6 tablets per day. Use with caution in elderly or debilitated patients. Abrupt discontinuation may cause withdrawal symptoms.
Tylenol with Codeine No. 3 contains 300 mg acetaminophen and 30 mg codeine phosphate. Codeine is a prodrug requiring CYP2D6 conversion to morphine; poor metabolizers have reduced efficacy, while ultrarapid metabolizers risk toxicity. Avoid exceeding 4 g acetaminophen daily due to hepatotoxicity. Use with caution in patients with respiratory compromise, as codeine can cause respiratory depression. Monitor for constipation; prescribe stool softeners prophylactically. Not recommended in children under 12 and contraindicated in post-tonsillectomy/adenoidectomy pain in children due to risk of fatal respiratory depression.
No interactions on record
No interactions on record
Common clinical questions about HYDROCODONE BITARTRATE AND HOMATROPINE METHYLBROMIDE vs TYLENOL W/ CODEINE NO. 3, answered by our medical review team.
HYDROCODONE BITARTRATE AND HOMATROPINE METHYLBROMIDE is a Opioid Agonist that works by Hydrocodone is a semisynthetic opioid agonist that binds to mu-opioid receptors in the CNS, inhibiting ascending pain pathways and altering pain perception. Homatropine methylbromide is an anticholinergic agent that reduces gastrointestinal motility and secretions.. TYLENOL W/ CODEINE NO. 3 is a Opioid Agonist that works by Codeine is a prodrug converted to morphine, which acts as a mu-opioid receptor agonist; acetaminophen inhibits cyclooxygenase (COX) and modulates cannabinoid and serotonergic pathways, with central analgesic effect.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between HYDROCODONE BITARTRATE AND HOMATROPINE METHYLBROMIDE and TYLENOL W/ CODEINE NO. 3 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 HYDROCODONE BITARTRATE AND HOMATROPINE METHYLBROMIDE is: Oral: 5 mg hydrocodone/1.5 mg homatropine every 4 to 6 hours as needed; maximum 30 mg hydrocodone per day.. The standard adult dose of TYLENOL W/ CODEINE NO. 3 is: 1-2 tablets (300 mg acetaminophen/30 mg codeine per tablet) orally every 4 hours as needed for pain; maximum 12 tablets 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 HYDROCODONE BITARTRATE AND HOMATROPINE METHYLBROMIDE and TYLENOL W/ CODEINE NO. 3 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. HYDROCODONE BITARTRATE AND HOMATROPINE METHYLBROMIDE is classified as Category D/X. First trimester: Limited data; hydrocodone is not a major teratogen but opioid use may be associated with neural tube defects (RR 1.5-2.0) based on some studies. Homatropine methyl. TYLENOL W/ CODEINE NO. 3 is classified as Category D/X. Acetaminophen: Generally considered low risk; no consistent evidence of major malformations. Codeine: First trimester: risk of neural tube defects, cleft palate; second trimester: . Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.
Hydrocodone: primarily hepatic via CYP2D6 and CYP3A4 to hydromorphone, norhydrocodone, and other metabolites. Homatropine methylbromide: poorly absorbed; metabolized via ester hydrolysis and renal excretion.
Codeine: primarily metabolized by CYP2D6 to morphine (active), and via CYP3A4 to norcodeine; acetaminophen: primarily metabolized by conjugation (glucuronidation, sulfation) and minimally by CYP2E1 and CYP1A2.
Hydrocodone and its metabolites are primarily excreted renally. Approximately 60% of a dose is eliminated in urine as unchanged drug and conjugates, with less than 5% excreted in feces. Homatropine methylbromide is a quaternary ammonium compound that is poorly absorbed and excreted mainly unchanged in feces via biliary elimination.
Acetaminophen: primarily renal (hepatic metabolism followed by renal excretion of metabolites; <5% unchanged). Codeine: renal (primarily as codeine and its metabolites, including morphine, norcodeine, and conjugated forms; 90% excreted in urine, 10% in feces).
Hydrocodone is approximately 20-30% bound to plasma proteins, primarily albumin. Homatropine methylbromide has negligible protein binding (<5%).
Acetaminophen: 10-25% (albumin). Codeine: 7-25% (albumin); morphine: 30-40%.
The volume of distribution for hydrocodone is approximately 3.3-4.7 L/kg, indicating extensive tissue distribution. For homatropine methylbromide, Vd is roughly 0.5-1 L/kg due to its quaternary structure limiting CNS penetration.
Acetaminophen: 0.9-1.0 L/kg (distributes throughout total body water). Codeine: 3-6 L/kg (highly tissue-bound, extensive distribution).
Hydrocodone has an oral bioavailability of approximately 50-60% due to first-pass metabolism. Homatropine methylbromide is poorly absorbed orally, with bioavailability less than 10%.
Acetaminophen: oral 88-100% (therapeutic doses). Codeine: oral 50-60% (first-pass metabolism; extensive variability due to CYP2D6 metabolism).
Child-Pugh A: No adjustment. Child-Pugh B: Reduce dose by 50%. Child-Pugh C: Avoid use or use with extreme caution with 75% dose reduction.
Child-Pugh Class A (mild): no adjustment; Class B (moderate): reduce dose by 50% or extend dosing interval to every 6 hours; Class C (severe): avoid use due to risk of acetaminophen toxicity and altered codeine metabolism.
Children ≥6 years: 2.5 mg hydrocodone/0.75 mg homatropine orally every 4-6 hours as needed; maximum 15 mg hydrocodone per day. Children <6 years: Not recommended.
Based on codeine component: weight-based dosing of 0.5-1 mg codeine/kg/dose every 4-6 hours as needed; maximum daily dose: 6 mg/kg/day of codeine. Use lowest effective dose. Contraindicated in children <12 years due to risk of respiratory depression.
Initiate at lowest effective dose (e.g., 2.5 mg hydrocodone/0.75 mg homatropine every 6 hours) with careful titration due to increased risk of falls, respiratory depression, and anticholinergic effects.
Starting dose: 1 tablet every 6 hours as needed; maximum 8 tablets per day. Use with caution due to increased sensitivity, reduced hepatic and renal function, and risk of falls. Monitor for constipation and respiratory depression.
WARNING: ADDICTION, ABUSE, AND MISUSE; LIFE-THREATENING 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.
Respiratory depression, especially in elderly or debilitated; CNS depression; risk of opioid-induced hyperalgesia; increased intracranial pressure; severe hypotension; anticholinergic effects (constipation, urinary retention, blurred vision); tolerance and dependence; interactions with alcohol and other CNS depressants.
Hypersensitivity to hydrocodone, homatropine, or any component; significant respiratory depression; acute or severe bronchial asthma; GI obstruction; paralytic ileus; suspected surgical abdomen; narrow-angle glaucoma; urinary retention; concurrent use of MAOIs within 14 days.
Avoid grapefruit and grapefruit juice as they may increase hydrocodone levels. Avoid alcohol as it enhances CNS depression. No other significant food interactions.
Avoid alcohol; concurrent use increases hepatotoxicity risk. Grapefruit juice may inhibit CYP3A4 metabolism, potentially altering codeine effectiveness (limited significance). High-fat meals may delay codeine absorption but do not require dose adjustment. Maintain adequate hydration and fiber intake to mitigate constipation.
Hydrocodone is excreted into breast milk (M/P ratio approximately 2.0-2.5 based on a single study). Relative infant dose estimated at 2-4% of maternal weight-adjusted dose. Homatropine methylbromide: Quaternary ammonium compound; expected minimal excretion but no data. American Academy of Pediatrics considers hydrocodone compatible with breastfeeding, but monitor infant for drowsiness, respiratory depression, and constipation. Avoid use in mothers with CYP2D6 ultra-rapid metabolizer phenotype due to increased morphine production.
Acetaminophen: Enters breast milk in low amounts (M/P ratio ~0.2-0.5); considered compatible. Codeine: Excreted into breast milk (M/P ratio ~2.4); variable due to CYP2D6 polymorphisms. Risk of opioid toxicity in nursing infants, especially in ultrarapid metabolizers; caution advised. American Academy of Pediatrics recommends avoiding if possible.
No specific pharmacokinetic studies in pregnancy for this combination. In pregnancy, increased plasma volume and renal clearance may reduce hydrocodone concentrations, potentially requiring dose increases for adequate analgesia. However, due to risk of neonatal withdrawal, use lowest effective dose for shortest duration. Homatropine methylbromide: No dose adjustment data; use cautiously due to potential for anticholinergic side effects.
Acetaminophen: No dose adjustment required. Codeine: Increased clearance and reduced efficacy in some pregnant patients; however, due to risks of neonatal withdrawal and respiratory depression, use lowest effective dose for shortest duration. Avoid in third trimester near delivery. Consider alternative analgesics if prolonged treatment needed.
Take exactly as prescribed. Do not take more than recommended.,Avoid alcohol or other sedatives while taking this medication.,May cause drowsiness or dizziness. Do not drive or operate machinery until you know how it affects you.,Report difficulty breathing, severe constipation, or urinary retention.,May be habit forming. Do not share with others.,Store safely away from children and pets.,Do not stop abruptly without consulting your doctor.
Take exactly as prescribed; do not increase dose or frequency without consulting your doctor.,Do not take other acetaminophen-containing products simultaneously; total daily acetaminophen from all sources should not exceed 4000 mg.,Avoid alcohol while taking this medication to prevent liver damage.,This drug may cause drowsiness or dizziness; do not drive or operate machinery until you know how it affects you.,Constipation is common; increase fluid and fiber intake, and consider a stool softener.,Discontinue and seek medical help if you experience signs of serotonin syndrome (e.g., agitation, hallucinations, rapid heart rate) or allergic reaction (e.g., rash, difficulty breathing).,Do not stop abruptly after long-term use; taper under medical supervision to avoid withdrawal symptoms.,Keep out of reach of children; accidental overdose of acetaminophen can be fatal.