Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
LORTAB vs ANEXSIA
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Hydrocodone is a mu-opioid receptor agonist; acetaminophen inhibits cyclooxygenase (COX) and modulates pain pathways centrally.
ANEXSIA is a combination of hydrocodone and acetaminophen. Hydrocodone is an opioid agonist that binds to mu-opioid receptors in the central nervous system, altering pain perception and emotional response to pain. Acetaminophen's analgesic mechanism is not fully understood but involves inhibition of COX enzymes in the CNS and modulation of descending serotonergic pathways.
Moderate to severe pain management (FDA),Off-label: acute pain, chronic pain
Relief of moderate to moderately severe pain
1-2 tablets (each containing 5 mg hydrocodone/325 mg acetaminophen) orally every 4-6 hours as needed for pain. Maximum acetaminophen 3000 mg/day.
50-100 mg orally every 4-6 hours as needed; maximum 400 mg/day.
Hydrocodone: 3.3-4.4 hours in adults; prolonged in hepatic/renal impairment (up to 6-8 hours). Clinical context: requires 4-6 hour dosing intervals; steady-state in ~24 hours.
Terminal elimination half-life is 4-6 hours in adults with normal renal function; prolonged to 12-24 hours in severe renal impairment (Cr Cl <30 m L/min).
Hydrocodone: CYP3A4, CYP2D6; acetaminophen: hepatic conjugation (glucuronidation, sulfation) and CYP450 (minor).
Hydrocodone is metabolized via CYP2D6 and CYP3A4 to hydromorphone and norhydrocodone. Acetaminophen is primarily metabolized via hepatic glucuronidation and sulfation; a minor pathway via CYP2E1 produces NAPQI, which is detoxified by glutathione.
Renal: ~90% (unchanged: ~5% hydrocodone, ~60% hydromorphone and other conjugates; codeine-like metabolites). Biliary/fecal: minor (<10%).
Approximately 70% renal (unchanged drug and metabolites), 20% biliary/fecal, 10% other.
Hydrocodone: ~20-30% bound (primarily albumin).
Approximately 95% bound to plasma albumin and alpha-1-acid glycoprotein.
Hydrocodone: 3.3-4.7 L/kg; indicates extensive tissue distribution.
0.2-0.4 L/kg, indicating limited extravascular distribution primarily confined to plasma and interstitial fluid.
Oral: ~90% (first-pass metabolism reduces to ~50% due to extensive hepatic extraction; absolute bioavailability not well defined, but high oral absorption).
Oral: 80-90%; Intramuscular: 90-100%; Rectal: 70-80%.
Hydrocodone: e GFR 30-59 m L/min: administer 50-75% of usual dose; e GFR 15-29 m L/min: 50% of usual dose; e GFR <15 m L/min: avoid or use with caution. Acetaminophen: no specific GFR-based adjustment; avoid in severe renal impairment due to metabolite accumulation.
GFR 30-89 m L/min: no adjustment; GFR 15-29 m L/min: 50% dose reduction; GFR <15 m L/min: avoid use.
Hydrocodone: Child-Pugh Class A: no adjustment; Class B: reduce dose by 50% and monitor; Class C: avoid. Acetaminophen: reduce dose or avoid in significant liver disease; maximum 2000 mg/day in mild-moderate impairment.
Child-Pugh A: no adjustment; Child-Pugh B: 50% dose reduction; Child-Pugh C: avoid use.
Not recommended for children <18 years due to risk of respiratory depression and acetaminophen toxicity. In specific circumstances, weight-based dosing for hydrocodone 0.1-0.2 mg/kg/dose every 4-6 hours, max 10 mg/dose; acetaminophen 10-15 mg/kg/dose, max 60 mg/kg/day, not to exceed 3000 mg/day.
1-2 mg/kg/dose orally every 6 hours; maximum 6 mg/kg/day.
Start at the low end of dosing range (e.g., 1 tablet of 5 mg hydrocodone/325 mg acetaminophen every 6 hours). Monitor for respiratory depression, sedation, and constipation. Avoid acetaminophen >3000 mg/day due to hepatotoxicity risk.
Initiate at 25 mg every 6 hours; increase cautiously; monitor renal function.
Risk of addiction, abuse, and misuse; life-threatening respiratory depression; accidental ingestion; neonatal opioid withdrawal syndrome; risk with CYP3A4 inhibitors or discontinuation; risk of medication errors.
Addiction, abuse, and misuse; life-threatening respiratory depression; accidental ingestion; neonatal opioid withdrawal syndrome; risks from concomitant use with benzodiazepines or other CNS depressants; hepatotoxicity from acetaminophen.
Addiction, abuse, misuse; respiratory depression; head injury; GI obstruction; hepatic toxicity; renal impairment; hypotension; adrenal insufficiency; seizures; serotonin syndrome; severe hypotension; risk with MAOIs; pregnancy; lactation.
Risk of respiratory depression, especially in elderly or debilitated patients; adrenal insufficiency; severe hypotension; seizures; opioid-induced hyperalgesia; acetaminophen hepatotoxicity (avoid exceeding 4 g/day); serotonin syndrome if used with serotonergic agents.
Hypersensitivity; respiratory depression; acute/severe asthma; GI obstruction; suspected surgical abdomen; severe hepatic impairment; concurrent use with MAOIs or within 14 days.
Hypersensitivity to hydrocodone or acetaminophen; significant respiratory depression; acute or severe bronchial asthma in an unmonitored setting; known or suspected GI obstruction; severe hepatic impairment; concomitant use of MAOIs or within 14 days.
Avoid grapefruit and grapefruit juice as they may alter hydrocodone metabolism. Alcohol must be strictly avoided due to additive CNS depression and increased acetaminophen hepatotoxicity. No other significant food interactions.
Avoid alcohol; may increase risk of hepatotoxicity and GI bleeding. Limit caffeine intake from coffee, tea, cola, or energy drinks due to added caffeine content. High-fat meals may delay absorption; take on empty stomach for faster onset if tolerated.
FDA Category C in 1st and 2nd trimesters; increased risk of neural tube defects and congenital heart defects with codeine use; risk of respiratory depression and neonatal withdrawal syndrome in 3rd trimester with prolonged use.
First trimester: Data are limited; no increased risk of major malformations reported in small studies. Second and third trimesters: Associated with premature closure of the ductus arteriosus and oligohydramnios due to fetal renal effects; avoid use after 30 weeks gestation.
Codeine is excreted into breast milk; M/P ratio approximately 2.5 for morphine (active metabolite); potential for infant CNS depression; use caution, especially in CYP2D6 ultra-rapid metabolizers.
Excreted into breast milk in low concentrations (M/P ratio not established). Not recommended during breastfeeding due to potential for adverse effects in the infant, including renal impairment and gastrointestinal bleeding.
Increased clearance of codeine in pregnancy may require higher doses or more frequent intervals; avoid in 3rd trimester due to risk of neonatal respiratory depression; use lowest effective dose for shortest duration.
Dose adjustment not generally required; however, due to increased renal clearance in pregnancy, shortened dosing intervals may be necessary for sustained efficacy. Use lowest effective dose for shortest duration.
Lortab (hydrocodone/acetaminophen) carries a boxed warning for respiratory depression, misuse/abuse, and neonatal opioid withdrawal syndrome. The acetaminophen component imposes a maximum dose of 4000 mg/day; caution with hepatic impairment. Use the lowest effective dose for the shortest duration. Consider naloxone co-prescribing for high-risk patients.
ANEXSIA is a combination analgesic containing paracetamol, ibuprofen, and caffeine. It is contraindicated in patients with active peptic ulcer disease, severe hepatic impairment, or hypersensitivity to NSAIDs. Avoid concurrent use with other NSAIDs or paracetamol-containing products. Monitor renal function in elderly or dehydrated patients. Caffeine may exacerbate anxiety or insomnia.
Take exactly as prescribed; do not increase dose or frequency without consulting your doctor.,Do not crush, chew, or dissolve tablets; swallow whole.,Avoid alcohol; it increases risk of liver damage and respiratory depression.,Do not drive or operate machinery until you know how Lortab affects you.,Discontinue and seek medical help if you experience signs of allergic reaction (rash, difficulty breathing) or liver injury (yellowing skin/eyes, dark urine).,Store securely out of reach of others; dispose of unused medication via take-back programs.
Do not exceed recommended dose; overdosage of paracetamol can cause liver damage.,Take with food or milk to reduce gastrointestinal upset.,Avoid alcohol while taking this medication to reduce risk of liver toxicity and GI bleeding.,Discontinue use and consult if signs of allergic reaction, GI bleeding, or liver problems occur.,Caffeine may cause nervousness, insomnia, or increased heart rate; limit caffeine-containing foods and beverages.
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 LORTAB vs ANEXSIA, answered by our medical review team.
LORTAB is a Opioid analgesic combination that works by Hydrocodone is a mu-opioid receptor agonist; acetaminophen inhibits cyclooxygenase (COX) and modulates pain pathways centrally.. ANEXSIA is a Opioid Analgesic Combination that works by ANEXSIA is a combination of hydrocodone and acetaminophen. Hydrocodone is an opioid agonist that binds to mu-opioid receptors in the central nervous system, altering pain perception and emotional response to pain. Acetaminophen's analgesic mechanism is not fully understood but involves inhibition of COX enzymes in the CNS and modulation of descending serotonergic pathways.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between LORTAB and ANEXSIA 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 LORTAB is: 1-2 tablets (each containing 5 mg hydrocodone/325 mg acetaminophen) orally every 4-6 hours as needed for pain. Maximum acetaminophen 3000 mg/day.. The standard adult dose of ANEXSIA is: 50-100 mg orally every 4-6 hours as needed; maximum 400 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 LORTAB and ANEXSIA 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. LORTAB is classified as Category C. FDA Category C in 1st and 2nd trimesters; increased risk of neural tube defects and congenital heart defects with codeine use; risk of respiratory depression and neonatal withdrawa. ANEXSIA is classified as Category C. First trimester: Data are limited; no increased risk of major malformations reported in small studies. Second and third trimesters: Associated with premature closure of the ductus . Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.