Indications for VIEKIRA PAK:
Chronic HCV genotype 1a (in combination with ribavirin) or 1b infection without cirrhosis or with compensated cirrhosis.
Test for HBV infection prior to initiation. Take with a meal. ≥18yrs: Give 2 ombitasvir/paritaprevir/ritonavir tabs once daily (in AM) and 1 dasabuvir tab twice daily (AM & PM). Genotype 1a without cirrhosis: treat for 12 weeks + ribavirin. Genotype 1a with compensated cirrhosis (Child-Pugh A): treat for 24 weeks + ribavirin (based on prior treatment history, 12 weeks treatment may be considered for some patients). Genotype 1b with or without compensated cirrhosis (Child-Pugh A): treat for 12 weeks. HCV/HIV-1 co-infection: follow recommendations above. Liver transplant recipients (with mild fibrosis): treat for 24 weeks with ribavirin. In combination with ribavirin: see full labeling.
<18yrs: not established.
VIEKIRA PAK Contraindications:
Moderate to severe hepatic impairment. Concomitant alfuzosin, ranolazine, dronedarone, colchicine (in renal and/or hepatic impairment), lurasidone, pimozide, ergot derivatives, ethinyl estradiol, cisapride, atorvastatin, lovastatin, simvastatin, everolimus, sirolimus, tacrolimus, lomitapide, efavirenz, sildenafil (as Revatio), triazolam, oral midazolam, carbamazepine, phenytoin, phenobarbital, apalutamide, rifampin, St. John’s Wort, gemfibrozil. When coadministered with ribavirin, its contraindications also apply to this combination regimen (eg, Pregnancy Cat.X).
VIEKIRA PAK Warnings/Precautions:
Risk of HBV reactivation in patients coinfected with HCV/HBV. Test all patients for HBV infection by measuring HBsAg and anti-HBc; if positive serologic evidence, monitor for hepatitis flare or HBV reactivation during and at post-treatment follow-up; treat if clinically indicated. Risk of hepatic decompensation/failure in patients with cirrhosis; assess for evidence or signs/symptoms prior to initiation; discontinue if occurs. Perform hepatic lab tests at baseline, during the first 4 weeks, and thereafter. Consider discontinuing if ALT persistently >10XULN. Discontinue if ALT elevation is accompanied with liver inflammation or increasing conjugated bilirubin, alkaline phosphatase, or INR. HCV/HIV-1 co-infected: give suppressive antiretroviral regimen. Pregnancy. Use progestin-only contraception or non-hormonal methods, if necessary. Nursing mothers.
VIEKIRA PAK Classification:
HCV NS5A inhibitor/HCV NS3/4A protease inhibitor/CYP3A inhibitor + HCV NS5B palm polymerase inhibitor.
VIEKIRA PAK Interactions:
See Contraindications. Concomitant certain immunosuppressants or chemotherapeutic agents: may increase risk of HBV reactivation. Discontinue ethinyl estradiol-containing products prior to starting; may resume 2 weeks after therapy completion. May potentiate substrates of CYP3A, UGT1A1, BCRP, OATP1B1, or OATP1B3. Potentiated by strong CYP3A inhibitors or CYP2C8, P-gp, BCRP, OATP1B1, or OATP1B3 inhibitors. Potentiates ketoconazole (limit max 200mg/day), pravastatin (max 40mg/day), rosuvastatin (max 10mg/day), cyclosporine (reduce to ⅕ of current dose and monitor renal function), acetaminophen/hydrocodone (reduce dose by 50% and monitor). Potentiates ARBs (eg, valsartan, losartan, candesartan), CCBs (eg, amlodipine, nifedipine, diltiazem, verapamil); reduce dose of these (amlodipine by at least 50%) and monitor; consider alternatives if adverse effects occur. May potentiate anticancer agents/kinase inhibitors (eg, encorafenib, fostamatinib, ibrutinib, ivosidenib). Concomitant quetiapine: consider alternative anti-HCV therapy; if necessary, reduce quetiapine to ⅙ of current dose and monitor. Concomitant calcineurin inhibitors (in liver transplant): adjust dose of these. Concomitant fluticasone may reduce serum cortisol; consider alternatives. Concomitant voriconazole, darunavir/ritonavir, lopinavir/ritonavir, rilpivirine, salmeterol, metformin (in renal or hepatic impairment), elagolix 200mg twice daily (for >1 month): not recommended. Concomitant atazanavir 300mg (without ritonavir): give only in the AM. Antagonizes carisoprodol, cyclobenzaprine, diazepam; increase dose if needed. May antagonize omeprazole; consider increasing omeprazole dose: max 40mg/day. Caution with antiarrhythmics (eg, amiodarone, bepridil, disopyramide, flecainide, systemic lidocaine, mexiletine, propafenone, quinidine); monitor. Monitor with furosemide, buprenorphine/naloxone, alprazolam. Monitor INR frequently with warfarin.
Fatigue, nausea, pruritus, other skin reactions, insomnia, asthenia.
For ribavirin specific dosing and safety information, refer to the full prescribing information.
Generic Drug Availability:
Monthly carton—4 x 7 daily dose packs