Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
ILOPERIDONE vs ANEXSIA 7.5/325
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Iloperidone is an atypical antipsychotic with high affinity for serotonin 5-HT2A and dopamine D2 receptors; also moderate affinity for D3, D4, 5-HT6, 5-HT7, and α1-adrenergic receptors; low affinity for H1, 5-HT1A, and α2-adrenergic receptors; no affinity for M1 muscarinic receptors.
Hydrocodone is a mu-opioid receptor agonist, producing analgesia and euphoria. Acetaminophen inhibits cyclooxygenase (COX) enzymes, reducing prostaglandin synthesis and providing analgesic and antipyretic effects.
Acute treatment of schizophrenia in adults
Management of moderate to moderately severe pain where treatment with an opioid is appropriate and for which alternative treatments are inadequate
1-2 mg orally twice daily; target dose 6-12 mg/day; maximum 12 mg/day
1 tablet (hydrocodone 7.5 mg / acetaminophen 325 mg) orally every 4 to 6 hours as needed for pain; maximum 6 tablets per day (hydrocodone 45 mg / acetaminophen 1950 mg).
Terminal elimination half-life 18 hours in extensive CYP2D6 metabolizers, 33 hours in poor metabolizers; clinical context: steady-state reached in ~5-7 days.
Hydrocodone: 3.8-4.5 hours (immediate-release). Acetaminophen: 2-3 hours. Clinical note: Half-life prolonged in hepatic impairment; requires dose adjustment.
Primarily metabolized by CYP3A4 and CYP2D6 to two major metabolites (P88 and P95); also a minor substrate of CYP1A2, CYP2C8, CYP2C9, CYP2C19, and CYP2E1.
Hydrocodone: CYP3A4 and CYP2D6; Acetaminophen: primarily via glucuronidation (UGT1A1, UGT1A6, UGT1A9) and sulfation, with minor oxidation by CYP2E1.
Primarily hepatic metabolism via CYP3A4 and CYP2D6; approximately 7% excreted unchanged in urine and 18% in feces; total renal elimination of metabolites ~25%, fecal ~60%.
Renal: ~90-100% as hydrocodone metabolites (conjugated) and unchanged hydrocodone; ~60% as acetaminophen metabolites (glucuronide, sulfate, cysteine); <5% unchanged acetaminophen. Biliary/fecal: <5%.
~95% bound to serum proteins, primarily albumin and alpha-1-acid glycoprotein.
Hydrocodone: ~20-30% (albumin). Acetaminophen: ~10-25% (albumin).
Vd/F ~20 L/kg (oral); large distribution indicates extensive tissue binding.
Hydrocodone: 3-4 L/kg (extensive tissue distribution). Acetaminophen: ~1 L/kg (uniformly distributed).
Oral bioavailability is approximately 96% relative to oral solution; food does not significantly affect absorption.
Oral: Hydrocodone ~70% (high first-pass metabolism); Acetaminophen ~85-90% (minimal first-pass).
GFR 30-59 m L/min: reduce dose by 50%; GFR 15-29 m L/min: reduce by 75%; GFR <15 m L/min: not recommended
For GFR 30-59 m L/min: administer every 6 hours; maximum 4 tablets per day. For GFR 15-29 m L/min: administer every 8 hours; maximum 3 tablets per day. For GFR <15 m L/min: not recommended due to accumulation of metabolites.
Child-Pugh class B: reduce dose by 50%; Child-Pugh class C: contraindicated
Child-Pugh Class A: no adjustment necessary. Child-Pugh Class B: reduce dose by 25-50% and extend dosing interval to every 6-8 hours; maximum 4 tablets per day. Child-Pugh Class C: contraindicated due to risk of hepatotoxicity.
Not established; safety and efficacy not evaluated in patients <18 years
Not recommended for pediatric patients; safety and efficacy not established for children under 18 years. For adolescents ≥18 years: adult dosing.
Initiate at 1 mg twice daily; increase slowly; monitor for orthostatic hypotension and anticholinergic effects
Initiate at 1 tablet (hydrocodone 5 mg / acetaminophen 325 mg) every 6 hours as needed; titrate cautiously due to increased sensitivity, decreased renal function, and risk of respiratory depression. Maximum 4 tablets per day.
Elderly patients with dementia-related psychosis treated with antipsychotic drugs are at an increased risk of death. Iloperidone is not approved for the treatment of patients with dementia-related psychosis.
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 due to acetaminophen.
Increased mortality in elderly patients with dementia-related psychosis,QT interval prolongation (particularly with concomitant use of drugs that prolong QT or in patients with risk factors),Neuroleptic malignant syndrome (NMS),Tardive dyskinesia,Metabolic changes (hyperglycemia, dyslipidemia, weight gain),Orthostatic hypotension (particularly during initial dose titration),Seizures,Leukopenia, neutropenia, and agranulocytosis,Body temperature regulation impairment,Dysphagia,Cognitive and motor impairment
Risk of opioid addiction, abuse, and misuse; life-threatening respiratory depression; accidental ingestion; neonatal opioid withdrawal syndrome; risks from concomitant use of alcohol, benzodiazepines, or other CNS depressants; hepatotoxicity; severe hypotension; adrenal insufficiency; seizures; GI obstruction; impaired mental/physical abilities; use in elderly, cachectic, or debilitated patients; renal impairment; hepatic impairment; pregnancy; labor and delivery; nursing mothers; pediatric use; driving and operating machinery.
Known hypersensitivity to iloperidone or any component of the formulation
Significant respiratory depression; acute or severe bronchial asthma; known or suspected GI obstruction; hypersensitivity to hydrocodone or acetaminophen; concomitant use of MAOIs or within 14 days of such therapy.
Grapefruit juice may inhibit CYP3A4 metabolism, increasing iloperidone concentrations; avoid concurrent use. High-fat meals may slightly reduce absorption; take consistency.
Avoid alcohol consumption due to increased risk of acetaminophen hepatotoxicity and CNS depression. No specific food restrictions, but grapefruit juice may theoretically affect hydrocodone metabolism via CYP3A4 inhibition; however, clinical significance is uncertain.
First trimester: Limited human data; animal studies show increased fetal resorption and developmental delays at doses similar to human exposure. Second and third trimesters: May cause extrapyramidal symptoms and/or withdrawal symptoms in neonates (e.g., agitation, hypertonia, hypotonia, tremor, somnolence, respiratory distress, feeding disorder).
FDA Category C (hydrocodone) and Category D (acetaminophen) in third trimester. First trimester: Acetaminophen associated with rare gastroschisis; hydrocodone risk of neural tube defects. Second trimester: No major malformations except with prolonged opioid use. Third trimester: Acetaminophen safe; hydrocodone risk of neonatal opioid withdrawal syndrome (NOWS). Avoid near term.
Iloperidone is excreted into human milk. M/P ratio: unknown. Use caution; consider benefits of breastfeeding vs. risk of infant exposure. Monitor infant for sedation, poor feeding, extrapyramidal symptoms.
Hydrocodone/acetaminophen excreted in breast milk. M/P ratio unknown. Hydrocodone relative infant dose <3% of weight-adjusted maternal dose. Acetaminophen relative infant dose <2%. Use with caution; monitor infant for sedation, apnea, poor feeding. Highest risk in CYP2D6 ultrarapid metabolizers.
No specific dose adjustment guidelines exist for pregnancy. Due to increased plasma volume and renal clearance during pregnancy, consider therapeutic drug monitoring to maintain efficacy. Lower doses may be needed if adverse effects occur; use lowest effective dose.
Increased clearance of hydrocodone in pregnancy may require dose adjustment; monitor for inadequate analgesia. Acetaminophen pharmacokinetics unchanged. Avoid high doses (hepatotoxicity risk). Consider baseline hepatic function. No specific dose adjustment recommended; titrate to effect.
Iloperidone is an atypical antipsychotic with a low propensity for extrapyramidal symptoms but significant QTc prolongation risk; obtain baseline ECG and monitor electrolytes. Titrate slowly to mitigate orthostatic hypotension due to alpha-1 blockade. Dosing adjustments required in CYP2D6 poor metabolizers (reduce dose by 50%). Avoid concomitant use with QT-prolonging drugs or CYP3A4/2D6 inhibitors/inducers.
ANEXSIA 7.5/325 (hydrocodone/acetaminophen) carries a boxed warning for acetaminophen hepatotoxicity; maximum acetaminophen dose from all sources should not exceed 4 g/day. Hydrocodone is metabolized by CYP2D6 to hydromorphone; ultrarapid metabolizers may experience toxicity. Avoid concurrent use with other CNS depressants including alcohol. Prescribe with caution in patients with renal impairment (hydrocodone accumulation) or hepatic impairment (acetaminophen toxicity). Monitor for signs of respiratory depression, especially at therapy initiation and dose titration. Use the lowest effective dose for the shortest duration.
Do not drive or operate machinery until you know how iloperidone affects you, as it may cause dizziness, drowsiness, or blurred vision.,Rise slowly from sitting or lying positions to prevent falls due to low blood pressure.,Report any fast, pounding, or irregular heartbeat, especially with lightheadedness or fainting.,Avoid alcohol and grapefruit juice as they may increase side effects or drug levels.,If you experience muscle stiffness, fever, confusion, or sweating, seek emergency help immediately, as these may be signs of neuroleptic malignant syndrome.
Do not exceed 6 tablets per day due to acetaminophen content.,Avoid alcohol while taking this medication.,Do not drive or operate heavy machinery until you know how this medication affects you.,Take exactly as prescribed; do not share with others.,Seek emergency help if you experience difficulty breathing, severe drowsiness, or signs of allergic reaction.,Store securely out of reach of children and dispose of unused medication properly.
"Iloperidone, an atypical antipsychotic, prolongs the QT interval by blocking cardiac potassium channels (hERG), while Methsuximide, a succinimide anticonvulsant, may also prolong the QT interval via similar mechanisms. Co-administration can lead to additive QT prolongation, increasing the risk of torsade de pointes and other ventricular arrhythmias. This is particularly dangerous in patients with electrolyte imbalances, bradycardia, or pre-existing cardiac disease."
"The interaction between iloperidone and aprepitant results from iloperidone's moderate inhibition of CYP3A4, the primary enzyme responsible for aprepitant metabolism. This inhibition can lead to increased aprepitant plasma concentrations, potentially enhancing its antiemetic effects and risk of adverse events such as hiccups, constipation, and headache. Clinical significance is greater during the 3-day aprepitant regimen for chemotherapy-induced nausea and vomiting, as elevated levels may prolong its therapeutic and side effect profile."
"Concomitant administration of propoxycaine, an ester-type local anesthetic, and iloperidone, an atypical antipsychotic, may increase the risk of QT interval prolongation and torsade de pointes due to additive effects on cardiac repolarization. Propoxycaine can also elevate catecholamine levels, potentially enhancing iloperidone's effects on blood pressure and heart rate. These interactions could manifest as palpitations, syncope, or life-threatening arrhythmias."
No interactions on record
Explore head-to-head clinical comparisons of other medications in the same therapeutic classes.
Common clinical questions about ILOPERIDONE vs ANEXSIA 7.5/325, answered by our medical review team.
ILOPERIDONE is a Atypical Antipsychotic that works by Iloperidone is an atypical antipsychotic with high affinity for serotonin 5-HT2A and dopamine D2 receptors; also moderate affinity for D3, D4, 5-HT6, 5-HT7, and α1-adrenergic receptors; low affinity for H1, 5-HT1A, and α2-adrenergic receptors; no affinity for M1 muscarinic receptors.. ANEXSIA 7.5/325 is a Opioid Analgesic Combination that works by Hydrocodone is a mu-opioid receptor agonist, producing analgesia and euphoria. Acetaminophen inhibits cyclooxygenase (COX) enzymes, reducing prostaglandin synthesis and providing analgesic and antipyretic effects.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between ILOPERIDONE and ANEXSIA 7.5/325 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 ILOPERIDONE is: 1-2 mg orally twice daily; target dose 6-12 mg/day; maximum 12 mg/day. The standard adult dose of ANEXSIA 7.5/325 is: 1 tablet (hydrocodone 7.5 mg / acetaminophen 325 mg) orally every 4 to 6 hours as needed for pain; maximum 6 tablets per day (hydrocodone 45 mg / acetaminophen 1950 mg).. 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 ILOPERIDONE and ANEXSIA 7.5/325 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. ILOPERIDONE is classified as Category A/B. First trimester: Limited human data; animal studies show increased fetal resorption and developmental delays at doses similar to human exposure. Second and third trimesters: May ca. ANEXSIA 7.5/325 is classified as Category C. FDA Category C (hydrocodone) and Category D (acetaminophen) in third trimester. First trimester: Acetaminophen associated with rare gastroschisis; hydrocodone risk of neural tube d. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.