Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
HY-PHEN vs ACTRON
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
HY-PHEN is a combination of hydrocodone (a mu-opioid receptor agonist) and acetaminophen (an analgesic and antipyretic). Hydrocodone binds to mu-opioid receptors in the CNS, altering pain perception and emotional response to pain. Acetaminophen inhibits cyclooxygenase (COX) enzymes, particularly in the CNS, reducing prostaglandin synthesis.
Acetaminophen (paracetamol) is a non-opioid analgesic and antipyretic. Its mechanism is not fully understood but involves inhibition of cyclooxygenase (COX) enzymes in the central nervous system, reducing prostaglandin synthesis. It also modulates the endocannabinoid system and serotonergic pathways.
Management of moderate to moderately severe pain,Off-label: Acute pain, postoperative pain, chronic pain (limited use due to acetaminophen toxicity risk)
Mild to moderate pain,Fever
1-2 tablets (acetaminophen 500 mg/hydrocodone 5-10 mg) orally every 4-6 hours as needed for pain; maximum 8 tablets per day.
Oral: 400 mg every 4-6 hours as needed for pain; maximum 1200 mg/day.
2-3 hours (terminal elimination half-life). Clinical context: Short half-life requires frequent dosing (every 4-6 hours) for sustained analgesic effect.
Terminal elimination half-life 2-4 hours; prolonged to 6-12 hours in elderly or renal impairment (Cr Cl <30 m L/min).
Hydrocodone is metabolized via CYP3A4 to hydromorphone (active) and via CYP2D6 to norhydrocodone. Acetaminophen is primarily metabolized via glucuronidation and sulfation; a minor pathway via CYP2E1 produces a hepatotoxic metabolite (NAPQI) that is normally detoxified by glutathione.
Primarily metabolized in the liver via glucuronidation (UGT1A1, UGT1A6, UGT1A9), sulfation (SULT1A1, SULT1A3), and oxidation (CYP2E1, CYP3A4) to form the toxic metabolite N-acetyl-p-benzoquinone imine (NAPQI), which is detoxified by glutathione.
Renal (primarily as glucuronide conjugates and unchanged drug). Approximately 90-95% eliminated in urine within 24 hours; fecal excretion <5%.
Renal: 90% as unchanged drug; biliary/fecal: 10% as metabolites.
25-35% bound to plasma proteins (mainly albumin).
>99% bound to albumin.
0.9-1.5 L/kg. Clinical meaning: Moderate Vd indicates distribution into total body water; does not extensively accumulate in tissues.
0.1-0.2 L/kg; indicates limited extravascular distribution.
Oral: 60-90% (first-pass metabolism reduces systemic availability); Rectal: 70-80%; IV/IM: 100%.
Oral: 70-90% (first-pass metabolism minimal); IV: 100%.
GFR 30-50 m L/min: administer at 75% of usual dose every 6 hours; GFR <30 m L/min: administer at 50% of usual dose every 8 hours. Avoid in severe renal impairment.
GFR <30 m L/min: Avoid use. GFR 30-50 m L/min: Reduce dose to 50% of normal, maximum 600 mg/day.
Child-Pugh Class A: no adjustment; Class B: reduce dose by 50% and extend interval to every 8 hours; Class C: contraindicated.
Child-Pugh Class B: Reduce dose by 50%; maximum 600 mg/day. Child-Pugh Class C: Contraindicated.
Not recommended for children under 18 years due to risk of opioid-related adverse effects; alternative analgesics preferred.
Children ≥12 years: 400 mg orally every 6-8 hours as needed; maximum 1200 mg/day. Children <12 years: Not recommended.
Initiate with lowest effective dose (e.g., acetaminophen 500 mg/hydrocodone 5 mg) every 6 hours; monitor for respiratory depression, constipation, and falls; may require dose reduction by 25-50% compared to younger adults.
Initiate at 200 mg every 6-8 hours; maximum 600 mg/day due to increased risk of gastrointestinal bleeding and renal impairment.
Addiction, abuse, and misuse; life-threatening respiratory depression; accidental ingestion of acetaminophen (especially in children) can cause hepatotoxicity; neonatal opioid withdrawal syndrome with prolonged use during pregnancy; risks from concomitant use with benzodiazepines or other CNS depressants (additive respiratory depression).
Acetaminophen has been associated with cases of acute liver failure, sometimes resulting in liver transplant and death. Most cases involve use of acetaminophen at doses exceeding 4000 mg per day, often involving more than one acetaminophen-containing product.
Hepatotoxicity due to acetaminophen (dose-dependent); respiratory depression (especially in elderly, debilitated, or COPD); opioid-induced hyperalgesia; adrenal insufficiency; severe hypotension; seizures; serotonin syndrome with serotonergic drugs; urinary retention; bile duct spasm; use in patients with head injury or increased intracranial pressure (risk of masking neurological signs); neonatal withdrawal syndrome.
Hepatotoxicity: risk increased with chronic alcohol use, liver disease, or use of other acetaminophen-containing products. Avoid exceeding 4000 mg/day. Severe skin reactions: Stevens-Johnson syndrome, toxic epidermal necrolysis, acute generalized exanthematous pustulosis. Hypersensitivity reactions: anaphylaxis.
Significant respiratory depression; acute or severe bronchial asthma; known or suspected gastrointestinal obstruction (e.g., paralytic ileus); severe hepatic impairment; hypersensitivity to hydrocodone, acetaminophen, or any component; use of MAO inhibitors within 14 days (hypertensive crisis).
Severe hepatic impairment or active liver disease. Known hypersensitivity to acetaminophen or any component of the formulation.
Avoid alcohol consumption due to increased risk of hepatotoxicity and CNS depression. Grapefruit juice may inhibit CYP2D6 metabolism of hydrocodone, potentially altering analgesic effect; avoid concurrent use. High-fat meals may increase absorption of hydrocodone; take consistently with or without food.
Avoid alcohol; may increase risk of GI bleeding. No specific food restrictions, but taking with food can reduce gastrointestinal irritation. Maintain adequate hydration to prevent renal impairment.
Pregnancy Category C. First trimester: No well-controlled studies; potential for fetal harm based on animal studies (cleft palate, skeletal anomalies). Second and third trimesters: Prolonged use may cause neonatal withdrawal syndrome (irritability, hypertonia, respiratory depression) if used near term. Avoid use in pregnancy unless benefit outweighs risk.
First trimester: Based on animal studies and limited human data, possible increased risk of cardiovascular and neural tube defects. Second/third trimester: Risk of premature closure of ductus arteriosus and oligohydramnios with prolonged use. Avoid after 30 weeks gestation.
HY-PHEN (hydrocodone/acetaminophen) is excreted into breast milk in low concentrations. M/P ratio for hydrocodone is approximately 2.0, for acetaminophen ~1.0. Use caution; monitor infant for sedation, respiratory depression, and poor feeding. Consider risk of neonatal withdrawal if maternal use is chronic.
Excreted in breast milk; M/P ratio 0.15. Low oral bioavailability to infant; considered compatible with breastfeeding. Monitor infant for sedation or feeding problems.
No specific dose adjustments established for pregnancy. Increased plasma volume and enhanced hepatic metabolism in pregnancy may reduce drug concentrations, potentially requiring higher doses to achieve analgesic effect. However, avoid high doses due to risk of acetaminophen hepatotoxicity and fetal opioid exposure. Use lowest effective dose for shortest duration.
Dose adjustment not typically required; however, due to increased renal clearance and volume of distribution in pregnancy, higher doses may be needed to achieve therapeutic effect. Use lowest effective dose for shortest duration.
HY-PHEN is a combination of hydrocodone and acetaminophen. Monitor for acetaminophen hepatotoxicity; maximum daily acetaminophen dose should not exceed 4 g from all sources. Hydrocodone is a prodrug metabolized by CYP2D6 to hydromorphone; poor metabolizers may have reduced analgesia while ultra-rapid metabolizers risk toxicity. Avoid concurrent use with other CNS depressants including alcohol due to additive respiratory depression. Taper dose when discontinuing after prolonged use to prevent withdrawal.
ACTRON (ketorolac tromethamine) is a nonsteroidal anti-inflammatory drug (NSAID) for short-term management of moderate to severe acute pain, typically not exceeding 5 days due to risk of GI bleeding, renal impairment, and cardiovascular events. Avoid in patients with active peptic ulcer disease, bleeding diathesis, or advanced renal disease. Monitor renal function and signs of bleeding. Use lowest effective dose for shortest duration. May cause bronchospasm in aspirin-sensitive asthma.
Take exactly as prescribed; do not increase dose or frequency without consulting your doctor.,Do not take other products containing acetaminophen (e.g., Tylenol, cold medicines) while using this medication to avoid liver damage.,Avoid alcohol completely while taking this drug; it increases the risk of liver damage and severe drowsiness.,Do not drive or operate heavy machinery until you know how this medication affects you; it may cause dizziness or drowsiness.,Store securely away from children and others; misuse can cause addiction, overdose, or death.,Do not stop taking suddenly after long-term use; your doctor will help you taper off to prevent withdrawal symptoms.
Take with food or milk to reduce stomach upset.,Do not take for more than 5 days as prescribed; longer use increases risk of serious side effects.,Avoid alcohol while taking this medication to lower risk of stomach bleeding.,Report any signs of bleeding (e.g., black stools, vomiting blood), unusual bruising, or decreased urination.,Do not take with other NSAIDs (e.g., ibuprofen, naproxen) or aspirin without consulting your doctor.,Inform your doctor about all medications, especially blood thinners (e.g., warfarin) and diuretics.,If you have asthma, be aware of potential bronchospasm; seek immediate help if you have breathing trouble.,Not recommended during pregnancy, especially in the third trimester.
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 HY-PHEN vs ACTRON, answered by our medical review team.
HY-PHEN is a Opioid Antitussive Combination that works by HY-PHEN is a combination of hydrocodone (a mu-opioid receptor agonist) and acetaminophen (an analgesic and antipyretic). Hydrocodone binds to mu-opioid receptors in the CNS, altering pain perception and emotional response to pain. Acetaminophen inhibits cyclooxygenase (COX) enzymes, particularly in the CNS, reducing prostaglandin synthesis.. ACTRON is a NSAID that works by Acetaminophen (paracetamol) is a non-opioid analgesic and antipyretic. Its mechanism is not fully understood but involves inhibition of cyclooxygenase (COX) enzymes in the central nervous system, reducing prostaglandin synthesis. It also modulates the endocannabinoid system and serotonergic pathways.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between HY-PHEN and ACTRON 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 HY-PHEN is: 1-2 tablets (acetaminophen 500 mg/hydrocodone 5-10 mg) orally every 4-6 hours as needed for pain; maximum 8 tablets per day.. The standard adult dose of ACTRON is: Oral: 400 mg every 4-6 hours as needed for pain; maximum 1200 mg/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 HY-PHEN and ACTRON 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. HY-PHEN is classified as Category C. Pregnancy Category C. First trimester: No well-controlled studies; potential for fetal harm based on animal studies (cleft palate, skeletal anomalies). Second and third trimesters:. ACTRON is classified as Category C. First trimester: Based on animal studies and limited human data, possible increased risk of cardiovascular and neural tube defects. Second/third trimester: Risk of premature closur. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.