Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
CODOXY vs HY-PHEN
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Oxycodone is a full opioid agonist with relative selectivity for the mu-opioid receptor, although it can bind to other opioid receptors at higher doses. The principal therapeutic action of oxycodone is analgesia. Like all full opioid agonists, there is no ceiling effect for analgesia. Oxycodone is combined with aspirin to provide additive analgesic effects.
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.
Management of moderate to moderately severe pain where the use of an opioid analgesic is appropriate
Management of moderate to moderately severe pain,Off-label: Acute pain, postoperative pain, chronic pain (limited use due to acetaminophen toxicity risk)
1-2 capsules orally every 4-6 hours as needed for pain, not to exceed 8 capsules per day. Each capsule contains 5 mg hydrocodone bitartrate and 325 mg acetaminophen.
1-2 tablets (acetaminophen 500 mg/hydrocodone 5-10 mg) orally every 4-6 hours as needed for pain; maximum 8 tablets per day.
Terminal half-life is 3.5 hours in patients with normal renal function; extends to 5-8 hours in moderate renal impairment.
2-3 hours (terminal elimination half-life). Clinical context: Short half-life requires frequent dosing (every 4-6 hours) for sustained analgesic effect.
Oxycodone is metabolized by CYP3A4 and CYP2D6. N-demethylation to noroxycodone (via CYP3A4) is the primary metabolic pathway. CYP2D6-mediated O-demethylation to oxymorphone is a minor pathway but produces a more potent metabolite.
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.
Renal excretion of unchanged drug accounts for approximately 70% of elimination; biliary/fecal excretion accounts for 30%.
Renal (primarily as glucuronide conjugates and unchanged drug). Approximately 90-95% eliminated in urine within 24 hours; fecal excretion <5%.
Approximately 92% bound to albumin.
25-35% bound to plasma proteins (mainly albumin).
2.4 L/kg; indicates extensive tissue distribution.
0.9-1.5 L/kg. Clinical meaning: Moderate Vd indicates distribution into total body water; does not extensively accumulate in tissues.
Oral: 60-70% due to first-pass metabolism.
Oral: 60-90% (first-pass metabolism reduces systemic availability); Rectal: 70-80%; IV/IM: 100%.
For GFR 30-50 m L/min: administer every 8 hours. For GFR 10-29 m L/min: administer every 12 hours. For GFR <10 m L/min: use not recommended.
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.
Child-Pugh Class A: no adjustment. Child-Pugh Class B: reduce dose by 50% and extend interval to every 8 hours. Child-Pugh Class C: contraindicated.
Child-Pugh Class A: no adjustment; Class B: reduce dose by 50% and extend interval to every 8 hours; Class C: contraindicated.
For children ≥2 years: 0.1-0.2 mg/kg hydrocodone component every 4-6 hours as needed, maximum 6 doses per day. Use weight-based dosing; do not exceed acetaminophen 75 mg/kg/day.
Not recommended for children under 18 years due to risk of opioid-related adverse effects; alternative analgesics preferred.
Initiate at lowest effective dose (e.g., 1 capsule every 6 hours) due to increased risk of respiratory depression and falls. Titrate cautiously. Maximum 6 capsules per day.
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.
Addiction, abuse, and misuse; life-threatening respiratory depression; accidental ingestion; neonatal opioid withdrawal syndrome; risks from concomitant use with benzodiazepines or other CNS depressants; and interactions with drugs affecting cytochrome P450 isoenzymes.
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).
Addiction, abuse, and misuse; life-threatening respiratory depression; accidental ingestion; neonatal opioid withdrawal syndrome; risks from concomitant use with benzodiazepines or other CNS depressants; severe hypotension; gastrointestinal obstruction; seizures; serotonin syndrome; adrenal insufficiency; and androgen deficiency.
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.
Significant respiratory depression; acute or severe bronchial asthma in an unmonitored setting or in the absence of resuscitative equipment; known or suspected gastrointestinal obstruction, including paralytic ileus; hypersensitivity to oxycodone, aspirin, or any component of the formulation.
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).
Avoid alcohol and grapefruit juice. Alcohol potentiates CNS depression. Grapefruit juice may increase codeine metabolism via CYP3A4, leading to variable effects. No significant food restrictions otherwise; take with food if GI upset occurs.
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.
No human data; animal studies not available. Avoid during pregnancy, especially first trimester, due to potential oxycodone-induced neural tube defects.
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.
Oxycodone is excreted into breast milk; M/P ratio ~3.6:1. Risk of infant sedation and respiratory depression. Contraindicated during breastfeeding.
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.
No established dose adjustments; increased clearance in pregnancy may require higher doses for analgesia, but use is contraindicated.
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.
CODOXY is a fixed-dose combination of codeine (opioid) and doxylamine (antihistamine). Use lowest effective dose for shortest duration due to opioid dependence and respiratory depression risk. Avoid in children <12 years for post-tonsillectomy pain and in those <18 with respiratory compromise. Monitor for CNS depression, especially with alcohol. Doxylamine adds anticholinergic effects (constipation, dry mouth, urinary retention). Caution in elderly, renal impairment, and breastfeeding.
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.
Take exactly as prescribed; do not increase dose or frequency without consulting your doctor.,This medication may cause drowsiness, dizziness, or blurred vision; avoid driving or operating machinery until you know how it affects you.,Avoid alcohol and other sedatives (e.g., benzodiazepines, sleep aids) as they increase risk of severe drowsiness and breathing problems.,Do not use with other products containing codeine or antihistamines (including cough/cold medicines).,Store securely away from children; misuse can cause addiction, overdose, or death.,If you are pregnant, plan to become pregnant, or are breastfeeding, inform your healthcare provider before use.,Common side effects: constipation, dry mouth, nausea. Increase fluid intake and fiber to prevent constipation.,Seek emergency help if you experience slow or shallow breathing, confusion, or fainting.
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.
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 CODOXY vs HY-PHEN, answered by our medical review team.
CODOXY is a Antitussive Combination that works by Oxycodone is a full opioid agonist with relative selectivity for the mu-opioid receptor, although it can bind to other opioid receptors at higher doses. The principal therapeutic action of oxycodone is analgesia. Like all full opioid agonists, there is no ceiling effect for analgesia. Oxycodone is combined with aspirin to provide additive analgesic effects.. 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.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between CODOXY and HY-PHEN 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 CODOXY is: 1-2 capsules orally every 4-6 hours as needed for pain, not to exceed 8 capsules per day. Each capsule contains 5 mg hydrocodone bitartrate and 325 mg acetaminophen.. 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.. 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 CODOXY and HY-PHEN 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. CODOXY is classified as Category C. No human data; animal studies not available. Avoid during pregnancy, especially first trimester, due to potential oxycodone-induced neural tube defects.. 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:. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.