Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
ANEXSIA 7.5/325 vs VOSEVI
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, producing analgesia and euphoria. Acetaminophen inhibits cyclooxygenase (COX) enzymes, reducing prostaglandin synthesis and providing analgesic and antipyretic effects.
VOSEVI (sofosbuvir, velpatasvir, and voxilaprevir) is a fixed-dose combination of a nucleotide analog NS5B polymerase inhibitor (sofosbuvir), an NS5A inhibitor (velpatasvir), and a NS3/4A protease inhibitor (voxilaprevir). The combination inhibits hepatitis C virus replication by targeting multiple viral proteins.
Management of moderate to moderately severe pain where treatment with an opioid is appropriate and for which alternative treatments are inadequate
Treatment of chronic hepatitis C virus genotype 1-6 infection in adults who have no prior treatment with a NS5A inhibitor and have been previously treated with a regimen containing sofosbuvir without a NS5A inhibitor,Treatment of chronic hepatitis C virus genotype 1-6 infection in adults who have prior treatment with a NS5A inhibitor-containing regimen
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).
One tablet (sofosbuvir 400 mg/velpatasvir 100 mg/voxilaprevir 100 mg) orally once daily with food for 8 weeks.
Hydrocodone: 3.8-4.5 hours (immediate-release). Acetaminophen: 2-3 hours. Clinical note: Half-life prolonged in hepatic impairment; requires dose adjustment.
Sofosbuvir: 0.5 h (parent), 27 h (GS-331007 metabolite); Velpatasvir: 17 h; Voxilaprevir: 33 h. Terminal half-lives support once-daily dosing; metabolite GS-331007 accumulates but is less active.
Hydrocodone: CYP3A4 and CYP2D6; Acetaminophen: primarily via glucuronidation (UGT1A1, UGT1A6, UGT1A9) and sulfation, with minor oxidation by CYP2E1.
Sofosbuvir is metabolized by cathepsin A and CES1 to the active metabolite GS-461203, followed by dephosphorylation. Velpatasvir and voxilaprevir are metabolized by CYP2B6, CYP2C8, CYP3A4 (minor). Voxilaprevir is also a substrate of OATP1B1/1B3.
Renal: ~90-100% as hydrocodone metabolites (conjugated) and unchanged hydrocodone; ~60% as acetaminophen metabolites (glucuronide, sulfate, cysteine); <5% unchanged acetaminophen. Biliary/fecal: <5%.
Sofosbuvir: 80% renal, 14% fecal; Velpatasvir: 94% fecal, 0.4% renal; Voxilaprevir: 40% renal, 47% fecal. VOSEVI components are eliminated primarily via biliary/fecal (velpatasvir, voxilaprevir) and renal (sofosbuvir) pathways.
Hydrocodone: ~20-30% (albumin). Acetaminophen: ~10-25% (albumin).
Sofosbuvir: ~85% bound; Velpatasvir: >99.5% bound; Voxilaprevir: >99% bound. Primarily to albumin.
Hydrocodone: 3-4 L/kg (extensive tissue distribution). Acetaminophen: ~1 L/kg (uniformly distributed).
Sofosbuvir: ~1.8 L/kg; Velpatasvir: ~4.9 L/kg; Voxilaprevir: ~3.9 L/kg. Large Vd indicates extensive tissue distribution, including liver (target organ).
Oral: Hydrocodone ~70% (high first-pass metabolism); Acetaminophen ~85-90% (minimal first-pass).
Oral: sofosbuvir ~92%, velpatasvir ~29%, voxilaprevir ~44% (fasted). Administer with food to increase absorption (especially voxilaprevir AUC 2- to 4-fold).
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.
No dose adjustment required for mild to moderate renal impairment (e GFR ≥30 m L/min/1.73 m²). For severe renal impairment (e GFR <30 m L/min/1.73 m²) or end-stage renal disease, safety and efficacy not established; use not recommended.
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.
Contraindicated in Child-Pugh class B or C decompensated cirrhosis due to increased voxilaprevir exposure. No dose adjustment required for Child-Pugh class A cirrhosis.
Not recommended for pediatric patients; safety and efficacy not established for children under 18 years. For adolescents ≥18 years: adult dosing.
Safety and efficacy in pediatric patients <18 years have not been established; no specific dosing recommendations.
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.
No dose adjustment required based on age. Clinical studies included patients ≥65 years with no overall differences in safety or efficacy; consider renal function monitoring.
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.
Risk of hepatitis B virus reactivation in patients coinfected with HCV and HBV. Test all patients for evidence of current or prior HBV infection before starting treatment. Monitor HCV/HBV coinfected patients for hepatitis B reactivation during treatment and post-treatment follow-up.
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.
Risk of HBV reactivation,Risk of bradycardia when coadministered with amiodarone; avoid use unless alternatives are not available,Decompensated hepatic impairment: not recommended for use in patients with moderate or severe hepatic impairment (Child-Pugh B or C),Drug interactions: potential for reduced therapeutic effect if given with P-gp inducers (e.g., rifampin) or moderate/strong CYP inducers
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.
Concomitant use with rifampin (CYP2B6 and P-gp inducer) due to significant decrease in voxilaprevir concentrations,Concomitant use with St. John's wort (Hypericum perforatum) due to decreased drug concentrations,Coadministration with rosuvastatin is contraindicated due to increased risk of myopathy/rhabdomyolysis,Severe hepatic impairment (Child-Pugh C)
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.
VOSEVI should be taken with food to ensure adequate absorption. A high-fat meal (approximately 800–1000 calories, 50% fat) increases absorption of velpatasvir and voxilaprevir. Avoid concurrent use with St. John's wort, rifampin, and other P-glycoprotein inducers, as they may reduce VOSEVI efficacy.
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.
VOSEVI is contraindicated in pregnancy due to risk of fetal harm. No adequate human data; animal studies show developmental toxicity at clinically relevant exposures. Use effective contraception during treatment and for 6 months after completion.
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 data on presence in human milk; animal studies indicate excretion. M/P ratio unknown. Risk of adverse effects in infant not excluded; advise against breastfeeding during therapy.
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.
No data on pharmacokinetic changes in pregnancy; dose adjustments not established. VOSEVI is not recommended in pregnancy; if inadvertent exposure occurs, consult specialist.
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.
VOSEVI is a fixed-dose combination of sofosbuvir (NS5B inhibitor), velpatasvir (NS5A inhibitor), and voxilaprevir (NS3/4A protease inhibitor) indicated for treatment-naive and treatment-experienced patients with chronic HCV genotype 1–6 without cirrhosis or with compensated cirrhosis. It is particularly useful for patients who have failed prior NS5A inhibitor-containing regimens, including those with genotype 3 and compensated cirrhosis. Monitor for hepatitis B reactivation in HBV co-infected patients. Dose adjustment not required for mild or moderate renal impairment, but safety not established in severe renal impairment or ESRD. Caution with amiodarone due to risk of serious bradycardia. Check for drug interactions with P-gp inducers, CYP2B6, CYP2C8, and CYP3A4 substrates.
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.
Take VOSEVI exactly as prescribed, usually one tablet once daily with food.,Do not skip doses or stop taking VOSEVI without talking to your doctor.,If you have hepatitis B co-infection, your doctor will monitor you for HBV reactivation during and after treatment.,Tell your doctor about all medications, including over-the-counter drugs, herbal supplements, and vitamins, as VOSEVI may interact with them.,Common side effects include headache, fatigue, diarrhea, and nausea. Contact your doctor if you experience severe abdominal pain, jaundice, or signs of liver injury.,VOSEVI does not prevent transmission of HCV. Practice safe sex and avoid sharing needles to reduce the risk of spreading the virus.
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 7.5/325 vs VOSEVI, answered by our medical review team.
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.. VOSEVI is a Direct-Acting Antiviral Combination that works by VOSEVI (sofosbuvir, velpatasvir, and voxilaprevir) is a fixed-dose combination of a nucleotide analog NS5B polymerase inhibitor (sofosbuvir), an NS5A inhibitor (velpatasvir), and a NS3/4A protease inhibitor (voxilaprevir). The combination inhibits hepatitis C virus replication by targeting multiple viral proteins.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between ANEXSIA 7.5/325 and VOSEVI 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 7.5/325 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).. The standard adult dose of VOSEVI is: One tablet (sofosbuvir 400 mg/velpatasvir 100 mg/voxilaprevir 100 mg) orally once daily with food for 8 weeks.. 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 7.5/325 and VOSEVI 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 7.5/325 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. VOSEVI is classified as Category C. VOSEVI is contraindicated in pregnancy due to risk of fetal harm. No adequate human data; animal studies show developmental toxicity at clinically relevant exposures. Use effective. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.