VICTRELIS
Clinical safety rating: caution
Comprehensive clinical and safety monograph for VICTRELIS (VICTRELIS).
Boceprevir is a direct-acting antiviral agent that inhibits the NS3/4A serine protease of hepatitis C virus (HCV), preventing proteolytic cleavage of the HCV polyprotein into mature forms and thereby inhibiting viral replication.
| Metabolism | Primarily metabolized by aldo-keto reductases (AKRs), with minor contributions from CYP3A4. |
| Excretion | Primarily hepatic via CYP3A4/5 metabolism; renal excretion of unchanged drug is minimal (<1%). Fecal excretion accounts for approximately 79% of the dose (mostly metabolites). Biliary excretion is significant, with about 9% recovered in feces as unchanged drug. Renal excretion of metabolites is about 9%. |
| Half-life | Terminal elimination half-life is approximately 9 to 11 hours in healthy subjects and in patients with HCV infection. This supports twice-daily dosing with a 7-day lead-in phase at 800 mg TID then 400 mg BID. |
| Protein binding | Approximately 75% bound to human plasma proteins, primarily albumin and alpha-1-acid glycoprotein. |
| Volume of Distribution | Apparent volume of distribution is about 1.2 L/kg, indicating extensive distribution into tissues. |
| Bioavailability | Oral bioavailability is approximately 50% (range 30–70%) under fed conditions; taking with food increases exposure compared to fasting. |
| Onset of Action | Oral: Peak serum concentrations are achieved within 1 to 2 hours. Antiviral effect (reduction in HCV RNA) is observed within 24 hours of the first dose. |
| Duration of Action | Clinical antiviral effect persists for the duration of dosing. After discontinuation, serum levels decline with a half-life of ~9-11 hours; viral rebound occurs within days if not on effective combination therapy. |
800 mg orally three times daily (every 7-9 hours) with food.
| Dosage form | CAPSULE |
| Renal impairment | No dose adjustment required for mild to moderate renal impairment. Not recommended for severe renal impairment (CrCl <30 mL/min) or end-stage renal disease including dialysis. |
| Liver impairment | Contraindicated in moderate to severe hepatic impairment (Child-Pugh B or C). No dose adjustment for mild hepatic impairment (Child-Pugh A). |
| Pediatric use | Safety and efficacy not established in pediatric patients under 18 years. Not recommended. |
| Geriatric use | No specific dose adjustment recommended; use caution due to age-related decline in renal function and comorbidities. Monitor renal function. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for VICTRELIS (VICTRELIS).
| Breastfeeding | No human data. Boceprevir is excreted in rat milk. M/P ratio unknown. Due to potential for adverse effects in the nursing infant, breastfeeding is not recommended during therapy and for at least 30 days after last dose. |
| Teratogenic Risk | Victrelis (boceprevir) is contraindicated in pregnancy due to teratogenicity observed in animal studies. First trimester: high risk of major congenital malformations including neural tube defects and craniofacial abnormalities. Second and third trimesters: risk of fetal growth restriction and potential neurodevelopmental harm. Ribavirin component intensifies risk. |
■ FDA Black Box Warning
Boceprevir should not be used alone for the treatment of chronic hepatitis C. It should only be administered in combination with peginterferon alfa and ribavirin. Fatal and life-threatening events have occurred in patients with significant hepatic impairment or decompensated cirrhosis.
| Serious Effects |
Hypersensitivity to boceprevir or any component of the formulation; pregnancy (when used in combination with ribavirin) and male partners of pregnant women; coadministration with drugs that are highly dependent on CYP3A4 for clearance and for which elevated plasma concentrations are associated with serious events (e.g., alfuzosin, amiodarone, ergot derivatives, lovastatin, simvastatin, oral midazolam, pimozide, sildenafil for pulmonary arterial hypertension, triazolam); coadministration with strong CYP3A4 inducers (e.g., rifampin, St. John's wort, carbamazepine, phenytoin, phenobarbital).
| Precautions | Hematologic effects (anemia, neutropenia) requiring dose reduction or discontinuation of ribavirin or peginterferon; increased risk of hepatic decompensation in patients with cirrhosis; embryo-fetal toxicity (boceprevir in combination with ribavirin); potential for drug interactions with strong CYP3A4 inducers; use in pregnancy category X (with ribavirin). |
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| Fetal Monitoring | Pregnancy test before initiation and monthly during treatment. Monitor for fetal anomalies via high-resolution ultrasound at 18-20 weeks. Maternal monitoring includes liver function tests, complete blood count, and viral load at regular intervals. |
| Fertility Effects | Boceprevir did not impair fertility in animal studies. However, ribavirin component causes reversible testicular toxicity in animals; human male fertility may be affected. Female fertility is unlikely impaired but caution is warranted. |