Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
TYLENOL W/ CODEINE NO. 2 vs HYDROCODONE POLISTIREX AND CHLORPHENIRAMINE POLISTIREX
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: June 2026 · OpiCalc Medical Review Team
Acetaminophen: Inhibits cyclooxygenase (COX) in the CNS, reducing prostaglandin synthesis, with weak peripheral COX inhibition. Codeine: Prodrug converted to morphine via CYP2D6; morphine acts as a mu-opioid receptor agonist, inhibiting ascending pain pathways and altering pain perception.
Hydrocodone is an opioid agonist that binds to mu-opioid receptors in the CNS, inhibiting ascending pain pathways and altering pain perception. Chlorpheniramine is an antihistamine that competitively antagonizes histamine at H1 receptors, reducing allergic symptoms.
Mild to moderate pain,Pain accompanied by fever
FDA-approved for relief of symptoms of upper respiratory allergies or common cold, including nasal congestion, rhinorrhea, sneezing, and cough.,Relief of moderate to moderately severe pain (hydrocodone component).,Symptomatic relief of allergic rhinitis, urticaria, and other allergic conditions (chlorpheniramine component).
1 to 2 tablets (300 mg acetaminophen/15 mg codeine phosphate per tablet) orally every 4 hours as needed for pain; maximum 12 tablets per day.
Adults: 10 m L (hydrocodone polistirex 10 mg/chlorpheniramine polistirex 8 mg) orally every 12 hours; not to exceed 20 m L per day.
Acetaminophen: 2-3 hours. Codeine: 2.5-3.5 hours. In hepatic impairment, half-life of codeine may be prolonged.
The terminal elimination half-life for hydrocodone from the polistirex formulation is approximately 3.8-4.5 hours in adults, with extended-release properties due to the polistirex complex. For chlorpheniramine polistirex, the half-life is about 20-24 hours, reflecting the prolonged release. These half-lives support twice-daily dosing in the extended-release formulation.
Not recommended for GFR < 30 m L/min; for GFR 30-59 m L/min, extend dosing interval to every 6 hours; avoid in severe renal impairment.
Cr Cl ≥30 m L/min: No adjustment. Cr Cl <30 m L/min: Avoid use due to accumulation of hydrocodone and chlorpheniramine.
Codeine is contraindicated in children younger than 12 years for postoperative management following tonsillectomy and/or adenoidectomy. Risk of respiratory depression and death in children with CYP2D6 ultra-rapid metabolizers. Avoid use in children 12–18 years with risk factors for respiratory depression.
Acetaminophen and codeine combination: Codeine crosses placenta. Chronic use during pregnancy may lead to neonatal opioid withdrawal syndrome (NOWS). First trimester: Limited data, but acetaminophen not associated with major malformations; codeine weakly associated with neural tube defects in some studies. Third trimester: Prolonged use may cause respiratory depression and NOWS. Avoid high doses and prolonged use.
First trimester: Inadequate human data for hydrocodone polistirex and chlorpheniramine polistirex combination; hydrocodone is an opioid and associated with neural tube defects and congenital heart defects in some studies; chlorpheniramine is generally considered low risk but data limited. Second and third trimesters: Chronic use may lead to opioid withdrawal in neonates; chlorpheniramine may cause anticholinergic effects. Near term: Prolonged use can cause respiratory depression, neonatal opioid withdrawal syndrome (NOWS).
Tylenol with Codeine No. 2 contains 300 mg acetaminophen and 15 mg codeine phosphate per tablet. Avoid exceeding 4 g/day acetaminophen due to hepatotoxicity risk. Codeine is a prodrug metabolized by CYP2D6 to morphine; poor metabolizers (7-10% of population) have reduced efficacy, while ultra-rapid metabolizers risk toxicity. Monitor for respiratory depression, especially in children, obese, or sleep apnea patients. Use lowest effective dose for shortest duration. Contraindicated post-tonsillectomy/adenoidectomy in children <12 years. Naloxone should be available if opioid-naive.
Hydrocodone polistirex is an extended-release formulation; avoid crushing or chewing. Chlorpheniramine polistirex provides sustained antihistamine effect. Monitor for respiratory depression, especially in opioid-naive patients. Use with caution in patients with asthma or COPD. May cause anticholinergic effects (dry mouth, urinary retention).
No interactions on record
No interactions on record
Common clinical questions about TYLENOL W/ CODEINE NO. 2 vs HYDROCODONE POLISTIREX AND CHLORPHENIRAMINE POLISTIREX, answered by our medical review team.
TYLENOL W/ CODEINE NO. 2 is a Opioid Agonist that works by Acetaminophen: Inhibits cyclooxygenase (COX) in the CNS, reducing prostaglandin synthesis, with weak peripheral COX inhibition. Codeine: Prodrug converted to morphine via CYP2D6; morphine acts as a mu-opioid receptor agonist, inhibiting ascending pain pathways and altering pain perception.. HYDROCODONE POLISTIREX AND CHLORPHENIRAMINE POLISTIREX is a Opioid Agonist that works by Hydrocodone is an opioid agonist that binds to mu-opioid receptors in the CNS, inhibiting ascending pain pathways and altering pain perception. Chlorpheniramine is an antihistamine that competitively antagonizes histamine at H1 receptors, reducing allergic symptoms.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between TYLENOL W/ CODEINE NO. 2 and HYDROCODONE POLISTIREX AND CHLORPHENIRAMINE POLISTIREX 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. 2 is: 1 to 2 tablets (300 mg acetaminophen/15 mg codeine phosphate per tablet) orally every 4 hours as needed for pain; maximum 12 tablets per day.. The standard adult dose of HYDROCODONE POLISTIREX AND CHLORPHENIRAMINE POLISTIREX is: Adults: 10 m L (hydrocodone polistirex 10 mg/chlorpheniramine polistirex 8 mg) orally every 12 hours; not to exceed 20 m L 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 TYLENOL W/ CODEINE NO. 2 and HYDROCODONE POLISTIREX AND CHLORPHENIRAMINE POLISTIREX 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. TYLENOL W/ CODEINE NO. 2 is classified as Category D/X. Acetaminophen and codeine combination: Codeine crosses placenta. Chronic use during pregnancy may lead to neonatal opioid withdrawal syndrome (NOWS). First trimester: Limited data,. HYDROCODONE POLISTIREX AND CHLORPHENIRAMINE POLISTIREX is classified as Category D/X. First trimester: Inadequate human data for hydrocodone polistirex and chlorpheniramine polistirex combination; hydrocodone is an opioid and associated with neural tube defects and . Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.
Acetaminophen: Hepatic via conjugation (glucuronidation, sulfation, CYP2E1 minor). Codeine: Prodrug metabolized by CYP2D6 to morphine; also metabolized by CYP3A4 to norcodeine and by glucuronidation.
Hydrocodone is metabolized via CYP2D6 and CYP3A4 to hydromorphone and norhydrocodone; chlorpheniramine is metabolized via CYP2D6 and CYP3A4 to desmethylchlorpheniramine.
Renal: 70-80% as glucuronide and sulfate conjugates of acetaminophen, 5-10% as unchanged acetaminophen, and 5-10% as unchanged codeine. Biliary/fecal: minor, <5%.
Hydrocodone polistirex and chlorpheniramine polistirex are excreted primarily renally. Hydrocodone and its metabolites are eliminated via kidneys (about 60-70% as unchanged drug and conjugates), with a small amount in feces (<10%). Chlorpheniramine is also predominantly renally excreted (30-50% unchanged, with metabolites). Biliary/fecal excretion accounts for less than 20% of total clearance for both components.
Acetaminophen: 10-25% (minimal). Codeine: 7-25%, primarily to albumin.
Hydrocodone is about 20% bound to plasma proteins. Chlorpheniramine is approximately 70% bound to plasma proteins, primarily albumin and alpha-1-acid glycoprotein.
Acetaminophen: 0.9-1.0 L/kg. Codeine: 2.2-3.5 L/kg (extensively distributed, including CNS).
Hydrocodone: Vd approximately 3.0-4.0 L/kg, indicating extensive tissue distribution. Chlorpheniramine: Vd about 5-7 L/kg, also widespread distribution. These high Vd values reflect deep tissue penetration.
Oral: Acetaminophen: 85-95%; Codeine: 50-70% (first-pass metabolism to morphine).
Oral bioavailability of hydrocodone from the polistirex formulation is around 30-50% due to first-pass metabolism; the polistirex complex provides sustained release. Chlorpheniramine polistirex oral bioavailability is about 25-50%, also with first-pass effect and extended release. Both components are well-absorbed in the gastrointestinal tract.
Contraindicated in severe hepatic impairment; for Child-Pugh A or B, reduce dose by 50% and monitor; avoid in Child-Pugh C.
Child-Pugh A: No adjustment. Child-Pugh B or C: Avoid use due to impaired clearance of hydrocodone and risk of toxicity.
Not recommended for children < 18 years due to risk of respiratory depression; for ages ≥18, same as adult dosing per body weight considerations.
Children ≥6 years: 5 m L (hydrocodone polistirex 5 mg/chlorpheniramine polistirex 4 mg) orally every 12 hours; not to exceed 10 m L per day. Children <6 years: Not recommended.
Initiate at half the adult dose (1 tablet every 4 hours as needed) due to increased sensitivity and renal/hepatic impairment; maximum 8 tablets per day.
Initiate at lower doses due to increased bioavailability of hydrocodone and anticholinergic sensitivity; 5 m L orally every 12 hours, titrate cautiously to a maximum of 10 m L per day.
Hydrocodone is associated with risks of addiction, abuse, misuse, respiratory depression, neonatal opioid withdrawal syndrome, and cytochrome P450 3A4 interaction. Concomitant use with CNS depressants (e.g., alcohol, benzodiazepines) may cause profound sedation, respiratory depression, coma, and death.
Avoid alcohol; may increase hepatotoxicity (acetaminophen) and CNS depression (codeine). No specific food restrictions, but grapefruit juice may inhibit CYP2D6 (codeine metabolism) theoretically; consider limiting grapefruit intake. Maintain adequate hydration to prevent constipation.
Avoid alcohol. Grapefruit juice may increase hydrocodone levels; limit or avoid consumption. No specific food restrictions.
Acetaminophen enters breast milk (M/P ratio ~0.91-1.42), considered compatible at therapeutic doses. Codeine enters milk (M/P ratio ~2.5) and may cause infant sedation; avoid in breastfeeding mothers who are ultra-rapid metabolizers of CYP2D6 due to risk of morphine accumulation. Use lowest effective dose for shortest duration.
Hydrocodone: Excreted into breast milk; M/P ratio approximately 0.6; caution due to potential CNS depression in infants, especially in CYP2D6 ultra-rapid metabolizers. Chlorpheniramine: Excreted in milk in small amounts; may cause drowsiness or irritability. Consider benefit-risk; alternative preferred.
No standard dose adjustment required for acetaminophen. Codeine: Pregnancy may increase clearance due to enhanced hepatic metabolism, possibly requiring dose adjustment for pain control. However, use lowest effective dose and avoid long-term use. Caution: Codeine is contraindicated in breastfeeding mothers (ultra-rapid metabolizer risk) and should be avoided in pregnancy with other opioid alternatives preferred.
No established dosing guidelines for this combination product. Increased renal clearance of hydrocodone in pregnancy may require dose titration to effect; chlorpheniramine pharmacokinetics not well studied. Consider using lowest effective dose for shortest duration; monitor for efficacy and toxicity. Avoid use during labor and delivery due to potential neonatal respiratory depression.
Take exactly as prescribed; do not increase dose or frequency.,Do not combine with other acetaminophen-containing products (e.g., cold medicines, sleep aids) to avoid liver damage.,Avoid alcohol while taking this medication.,Do not drive or operate machinery until you know how this drug affects you.,Seek emergency care if you experience slow/shallow breathing, confusion, or severe drowsiness.,Store securely away from children; accidental overdose can be fatal.,Discontinue and contact doctor if signs of allergic reaction (rash, swelling, difficulty breathing) occur.,Do not crush or chew tablets; swallow whole with water.,Inform doctor of all medications, especially MAOIs, SSRIs, or other CNS depressants.,Codeine can cause constipation; increase fluid and fiber intake as preventive measure.
Take exactly as prescribed; do not crush, chew, or dissolve the capsules.,Avoid alcohol and other CNS depressants (sedatives, tranquilizers).,Do not drive or operate machinery until you know how this medicine affects you.,Notify your doctor if you have trouble breathing, severe drowsiness, or difficulty urinating.,Store at room temperature away from moisture and heat.