Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
ANEXSIA 7.5/650 vs ZEPATIER
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 that inhibits ascending pain pathways and alters pain perception; acetaminophen inhibits cyclooxygenase (COX) enzymes, primarily in the CNS, reducing prostaglandin synthesis and fever.
ZEPATIER is a fixed-dose combination of elbasvir, an HCV NS5A inhibitor, and grazoprevir, an HCV NS3/4A protease inhibitor. Elbasvir inhibits HCV NS5A, disrupting viral replication and assembly. Grazoprevir inhibits the HCV NS3/4A serine protease, preventing cleavage of the HCV polyprotein into mature viral proteins.
Management of acute pain severe enough to require an opioid analgesic and for which alternative treatments are inadequate
Treatment of chronic hepatitis C virus (HCV) genotype 1 or 4 infection in adults,Treatment of chronic HCV genotype 1 or 4 infection in pediatric patients 12 years of age and older or weighing at least 30 kg
1 tablet orally every 4 to 6 hours as needed; maximum 6 tablets per day.
One tablet (elbasvir 50 mg/grazoprevir 100 mg) orally once daily.
Hydrocodone: Terminal half-life 3.8-7.2 hours (mean 5.6 h). Acetaminophen: 1.5-2.5 hours (therapeutic) but prolonged to >4 hours in overdose with hepatotoxicity risk.
Elbasvir: terminal half-life approximately 24 hours. Grazoprevir: terminal half-life approximately 31 hours. The prolonged half-lives support once-daily dosing and allow for sustained viral suppression.
Hydrocodone: CYP3A4 and CYP2D6; acetaminophen: primarily liver glucuronidation (UGT1A1, UGT1A6, UGT1A9) and sulfation (SULT1A1, SULT1A3), with minor CYP2E1 oxidation.
Elbasvir is metabolized primarily by CYP3A. Grazoprevir is metabolized primarily by CYP3A. Mild oxidation and glucuronidation are minor pathways.
Hydrocodone: Renal elimination of metabolites (hydromorphone, norhydrocodone) and unchanged drug accounts for ~60-90% of clearance. Acetaminophen: ~85% of dose is excreted in urine as glucuronide and sulfate conjugates; 5-10% unchanged; 2-5% as mercapturate.
Elbasvir: primarily biliary/fecal (≥90% as metabolites, <1% unchanged in urine). Grazoprevir: primarily biliary/fecal (≥90% as metabolites, <1% unchanged in urine). Renal elimination is negligible for both.
Hydrocodone: ~36% bound to serum proteins. Acetaminophen: 10-25% bound (minimal binding).
Elbasvir: ≥99.9% bound, primarily to albumin and α1-acid glycoprotein. Grazoprevir: 98.8% bound, primarily to albumin and α1-acid glycoprotein.
Hydrocodone: Vd ~3-5 L/kg (wide distribution). Acetaminophen: Vd ~0.9-1.0 L/kg (primarily body water).
Elbasvir: apparent Vd approximately 4.5 L/kg (high, indicating extensive tissue distribution). Grazoprevir: apparent Vd approximately 19 L/kg (very high, likely due to binding to plasma proteins and tissue uptake).
Oral: Hydrocodone ~70-80% (variable first-pass). Acetaminophen ~63-89% (mean 75-80%).
Elbasvir: absolute bioavailability not determined in humans; oral absorption is high. Grazoprevir: absolute bioavailability approximately 27% after oral administration; absorption is enhanced with food (high-fat meal increases AUC by 1.5-fold).
Cr Cl <30 m L/min: contraindicated; Cr Cl 30-60 m L/min: maximum 3 tablets per day; given the hydrocodone component, avoid in severe renal impairment.
No dose adjustment required for any degree of renal impairment including end-stage renal disease on dialysis.
Child-Pugh Class A: no adjustment; Child-Pugh Class B: reduce dose by 50% and monitor; Child-Pugh Class C: contraindicated due to hydrocodone.
Contraindicated in moderate (Child-Pugh B) or severe (Child-Pugh C) hepatic impairment. No dose adjustment required in mild (Child-Pugh A) hepatic impairment.
Not recommended in pediatric patients due to risk of respiratory depression; for ages <18, contraindicated.
Not approved for use in pediatric patients; safety and efficacy not established.
Initiate with lowest effective dose, monitor for respiratory depression and constipation; maximum 4 tablets per day in patients >65 years.
No dose adjustment required; however, clinical studies indicate similar safety and efficacy as in younger adults, but caution is warranted due to potential age-related comorbidities.
Risk of addiction, abuse, and misuse; life-threatening respiratory depression; accidental ingestion (especially in children) can be fatal; neonatal opioid withdrawal syndrome; cytochrome P450 3A4 interaction (concomitant use with CYP3A4 inhibitors may increase hydrocodone levels); risk of medication errors (confusion between different strengths).
Risk of hepatitis B virus (HBV) reactivation in patients coinfected with HCV and HBV, which may result in fulminant hepatitis, hepatic failure, and death. Test all patients for evidence of current or prior HBV infection before initiating treatment.
Addiction, abuse, and misuse; respiratory depression; neonatal opioid withdrawal syndrome; interactions with CNS depressants; risk of serotonin syndrome with serotonergic drugs; adrenal insufficiency; hypotension; seizures; gastrointestinal obstruction; severe cutaneous reactions (acetaminophen); hepatotoxicity (acetaminophen overdose); acute abdominal conditions; impaired mental/physical abilities; elderly/debilitated patients; renal/hepatic impairment.
Risk of hepatitis B virus reactivation,Hepatic decompensation with use in patients with moderate or severe hepatic impairment (Child-Pugh B or C),Elevation of total bilirubin and/or ALT levels,Risk of adverse reactions due to drug interactions (e.g., strong CYP3A inducers/inhibitors)
Significant respiratory depression; acute or severe bronchial asthma (without monitoring or resuscitative equipment); known or suspected gastrointestinal obstruction (including paralytic ileus); hypersensitivity to hydrocodone or acetaminophen; use with MAOIs or within 14 days of such therapy.
Moderate or severe hepatic impairment (Child-Pugh B or C),Use with strong CYP3A inducers (e.g., rifampin, St. John's wort, carbamazepine, phenytoin),Use with certain HIV medications (e.g., efavirenz, etravirine, nevirapine, atazanavir/ritonavir, lopinavir/ritonavir, darunavir/ritonavir, tipranavir/ritonavir),Use with cyclosporine
Avoid alcohol due to increased risk of acetaminophen hepatotoxicity and additive CNS depression. Grapefruit juice may increase hydrocodone absorption; consider avoiding. No other significant food interactions.
ZEPATIER can be taken with or without food. No specific food restrictions are required. Grapefruit and grapefruit juice may increase exposure to grazoprevir; although not contraindicated, consider avoiding large quantities.
FDA Category C. First trimester: Possible increased risk of cardiac defects with oxycodone. Second/third trimester: Chronic use may lead to neonatal opioid withdrawal syndrome; no clear teratogenicity. Acetaminophen is generally safe, but high doses may be hepatotoxic.
ZEPATIER (grazoprevir/elbasvir) is contraindicated in pregnancy due to the ribavirin component in some regimens. Ribavirin is teratogenic in all trimesters, causing fetal malformations and embryolethality. Grazoprevir/elbasvir alone has no adequate human data, but animal studies show no teratogenicity. However, combination with ribavirin mandates avoidance in pregnancy.
Oxycodone: M/P ratio ~0.8-3; present in milk; risk of neonatal sedation. Acetaminophen: M/P ~0.8-1, low risk. Avoid due to oxycodone; consider alternative analgesic.
No data on human milk excretion. M/P ratio unknown. Ribavirin accumulates in breast milk and is contraindicated during breastfeeding. Grazoprevir/elbasvir: animal studies show excretion in milk; potential for adverse effects. Avoid breastfeeding during treatment and for 7 days after last dose.
Increased clearance of oxycodone in pregnancy may require increased dose; acetaminophen pharmacokinetics unchanged. Adjust based on pain control and withdrawal risk.
No dose adjustment studies in pregnancy. ZEPATIER is not recommended during pregnancy due to ribavirin component. If inadvertently used, no specific dose adjustment; consult maternal-fetal specialist.
Fixed-dose combination of hydrocodone bitartrate (7.5 mg) and acetaminophen (650 mg). Hydrocodone is a schedule II controlled substance with high abuse potential. Acetaminophen hepatotoxicity risk increases above 3 g/day; prescribe no more than 4 doses per day. Monitor for respiratory depression, especially in opioid-naïve patients. Avoid in severe hepatic impairment. Use with caution in patients with COPD, sleep apnea, or concurrent CNS depressants. Consider naloxone co-prescription if high opioid dose or concurrent benzodiazepine use.
ZEPATIER (elbasvir/grazoprevir) is indicated for chronic HCV genotypes 1 or 4. Prior to initiation, test for NS5A resistance-associated substitutions (RASs) in genotype 1a. In patients with genotype 1a and baseline NS5A RASs, treatment duration is 16 weeks with ribavirin. Avoid in moderate to severe hepatic impairment (Child-Pugh B or C). Monitor hepatic function closely. Coadministration with strong CYP3A4 inducers (e.g., rifampin, carbamazepine) is contraindicated. Also contraindicated with OATP1B1/3 inhibitors (e.g., cyclosporine) and certain HIV protease inhibitors (e.g., atazanavir, darunavir, lopinavir). Grazoprevir increases serum creatinine due to OATP2B1 inhibition, but this does not reflect true renal function decline.
Take exactly as prescribed; do not increase dose or frequency.,Do not take with alcohol or other medications containing acetaminophen.,May cause drowsiness or dizziness; avoid driving or operating machinery until effects are known.,Store securely out of reach of children and others; dispose of unused tablets properly.,Seek emergency care for difficulty breathing, severe sedation, or signs of allergic reaction.,Do not abruptly stop after prolonged use; withdrawal symptoms may occur.
Take ZEPATIER exactly as prescribed, one tablet once daily with or without food.,Do not stop or skip doses without consulting your healthcare provider.,Inform your doctor of all medications you take, including over-the-counter drugs and herbal supplements, to avoid serious interactions.,Notify your healthcare provider immediately if you experience symptoms of liver problems: yellowing of skin or eyes, dark urine, pale stools, nausea, vomiting, or right upper abdominal pain.,ZEPATIER may elevate creatinine levels without reflecting kidney damage; your doctor will monitor appropriately.,If you have genotype 1a HCV, your doctor will test for specific resistance mutations to determine the correct treatment duration.,Avoid alcohol during treatment as it can exacerbate liver injury.,Use effective contraception during treatment and for 2 weeks after the last dose if you or your partner can become pregnant.
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 ANEXSIA 7.5/650 vs ZEPATIER, answered by our medical review team.
ANEXSIA 7.5/650 is a Opioid Analgesic Combination that works by Hydrocodone is a mu-opioid receptor agonist that inhibits ascending pain pathways and alters pain perception; acetaminophen inhibits cyclooxygenase (COX) enzymes, primarily in the CNS, reducing prostaglandin synthesis and fever.. ZEPATIER is a Direct-Acting Antiviral (HCV) that works by ZEPATIER is a fixed-dose combination of elbasvir, an HCV NS5A inhibitor, and grazoprevir, an HCV NS3/4A protease inhibitor. Elbasvir inhibits HCV NS5A, disrupting viral replication and assembly. Grazoprevir inhibits the HCV NS3/4A serine protease, preventing cleavage of the HCV polyprotein into mature viral proteins.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between ANEXSIA 7.5/650 and ZEPATIER 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 ANEXSIA 7.5/650 is: 1 tablet orally every 4 to 6 hours as needed; maximum 6 tablets per day.. The standard adult dose of ZEPATIER is: One tablet (elbasvir 50 mg/grazoprevir 100 mg) orally once daily.. 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 ANEXSIA 7.5/650 and ZEPATIER 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. ANEXSIA 7.5/650 is classified as Category C. FDA Category C. First trimester: Possible increased risk of cardiac defects with oxycodone. Second/third trimester: Chronic use may lead to neonatal opioid withdrawal syndrome; no . ZEPATIER is classified as Category C. ZEPATIER (grazoprevir/elbasvir) is contraindicated in pregnancy due to the ribavirin component in some regimens. Ribavirin is teratogenic in all trimesters, causing fetal malformat. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.