Glecaprevir-Pibrentasvir

• Chronic Hepatitis C (All Genotypes)
• HCV Treatment
• Direct-Acting Antiviral Therapy
• HCV/HIV Coinfection

Glecaprevir/pibrentasvir, marketed as Mavyret, is a once-daily, fixed-dose oral combination that provides pangenotypic — meaning effective against all six major HCV genotypes — direct-acting antiviral (DAA) therapy for chronic hepatitis-c. For most treatment-naive adults without cirrhosis, an 8-week course produces sustained virologic response (functional cure) in over 95% of patients, transforming what was once a year-long interferon-based ordeal with debilitating side effects into a brief, well-tolerated outpatient regimen. The simplification of HCV treatment is one of the most significant advances in modern internal medicine, and primary care now plays a growing role in identification, treatment, and follow-up under guidance from hepatology and infectious disease.

Mechanism of Action

The regimen pairs two DAAs that attack HCV at independent steps in its replication cycle, raising the genetic barrier to resistance. Glecaprevir inhibits the NS3/4A serine protease that cleaves the viral polyprotein into the individual proteins HCV needs to replicate; without functional NS3/4A, the virus cannot complete polyprotein processing or RNA replication. Pibrentasvir binds NS5A, a protein essential for membranous web assembly, viral RNA replication, and virion packaging. Both drugs retain potency against the resistance-associated substitutions (RASs) that limit older NS3 and NS5A inhibitors, which is why this regimen works against genotype 3 — historically the hardest to cure — and against many treatment-experienced patients. Both components are predominantly biliary-excreted with negligible renal clearance, making the regimen safe across the full spectrum of kidney function including dialysis. The AASLD/IDSA HCV Guidance details current first-line regimens, durations, and the simplified treatment algorithm that allows treatment without genotype testing for most patients without cirrhosis. The CDC HCV resources provide patient-facing education on transmission, screening, and cure.

Clinical Use

This combination is a preferred regimen for treatment-naive adults and adolescents 12 years and older with chronic HCV genotypes 1–6, with or without compensated cirrhosis. For patients without cirrhosis, treatment is 8 weeks; for those with compensated cirrhosis it is also 8 weeks across most genotypes (a notable simplification from earlier guidance that required 12 weeks). Treatment-experienced patients with prior NS5A or NS3 exposure require 12–16 weeks based on prior regimen and genotype. Sofosbuvir/velpatasvir (sofosbuvir-velpatasvir) is the main alternative pangenotypic regimen and is generally preferred when significant CYP3A4 drug interactions exist or in moderate-to-severe hepatic impairment, where Mavyret is contraindicated. HCV/HIV coinfection is treated with the same regimen, although antiretroviral interactions must be reviewed; bictegravir-emtricitabine-tenofovir and dolutegravir-based regimens are typically compatible. Universal screening for HCV in adults aged 18 and older at least once in a lifetime — and in pregnant individuals during each pregnancy — is now recommended by USPSTF and CDC, expanding the pool of patients who can benefit. Patients with cirrhosis need ongoing surveillance for hepatocellular carcinoma even after cure, because the underlying fibrosis and field cancerization persist.

How to Take It

Take all three film-coated tablets together once daily with food — fat in the meal substantially improves absorption of both components. Pick a consistent time of day to anchor the dose; an evening meal works well for most patients because it pairs naturally with established routines. Do not skip doses or stop early, even if you feel completely well, because the high cure rate depends on uninterrupted exposure across the full course. If a dose is taken less than 18 hours late, take it with food and resume the schedule; if more than 18 hours late, skip and take the next scheduled dose. If vomiting occurs within four hours of a dose, take a replacement dose; after four hours, do not. Store tablets at room temperature in the original packaging. Do not start St. John's wort, rifampin, carbamazepine, phenytoin, or oxcarbazepine while on therapy — these inducers can drop drug levels enough to allow viral breakthrough. Avoid grapefruit only if drug-interaction review identifies a specific concern. Side effects are generally mild: headache, fatigue, and nausea are most common in the first two weeks and typically resolve.

Monitoring and Follow-Up

Before treatment, all patients need HBV screening — HBsAg, anti-HBc, and anti-HBs — because of the boxed warning for HBV reactivation; patients with active HBV should be co-managed with antiviral suppression. Baseline labs include a CBC, comprehensive metabolic panel with ALT/AST and direct bilirubin, INR, HCV RNA, and HCV genotype if not previously documented and required by the treatment algorithm. HIV testing is also recommended along with an assessment of fibrosis stage using FIB-4 or transient elastography to determine cirrhosis status. During therapy, repeat liver enzymes at 4 weeks if symptomatic, in cirrhotic patients, or in those at higher risk for hepatic decompensation. The definitive endpoint is HCV RNA measured 12 weeks after the last dose — undetectable HCV RNA at that point defines sustained virologic response (SVR12) and is considered cure. Our understanding-blood-work-lab-panels primer can help patients interpret these results. Reinfection risk persists for patients with ongoing exposures (injection drug use, certain sexual practices), and periodic re-screening is appropriate.

Special Populations

The regimen is contraindicated in moderate to severe hepatic impairment (Child-Pugh B or C) — sofosbuvir/velpatasvir is preferred there in coordination with hepatology. No dose adjustment is needed for any degree of renal impairment, including hemodialysis, which makes this a particularly attractive option in patients with chronic kidney disease where many other medications require careful adjustment. Pregnancy data are limited; treatment is generally deferred until after delivery unless there is a compelling reason, although emerging data on DAAs in pregnancy are encouraging. Coadministration with atazanavir or ethinyl estradiol-containing contraceptives should be avoided due to ALT elevation risk; alternative contraception (progestin-only or non-hormonal) is recommended during therapy. Statins often need to be paused or dose-reduced — atorvastatin and simvastatin in particular have significant interactions; rosuvastatin should not exceed 10 mg daily; pravastatin requires dose reduction. Adolescents 12–17 years are dosed identically to adults; younger pediatric patients use weight-based granule packets.

Drug Interactions and Practical Counseling

Despite a generally favorable safety profile, the regimen has clinically important interactions. Atazanavir and rifampin are absolute contraindications. Strong CYP3A4 and P-glycoprotein inducers — including phenytoin, carbamazepine, oxcarbazepine, efavirenz, and St. John's wort — can markedly reduce drug levels and risk treatment failure; these should be paused or substituted when feasible. Statin doses must be adjusted: simvastatin and lovastatin are not recommended; atorvastatin and pravastatin require dose reduction; rosuvastatin should not exceed 10 mg daily. Ethinyl estradiol-containing contraceptives can raise ALT and should be replaced with progestin-only or non-hormonal methods during therapy and for a short period afterward. Cyclosporine over 100 mg per day is not recommended. P-glycoprotein substrates including digoxin, dabigatran, and edoxaban may need monitoring. Always perform a complete medication reconciliation including over-the-counter products, supplements, and recreational substances before initiating.

Post-Cure Care and Reinfection Prevention

Sustained virologic response is curative for the original infection but not protective against reinfection. Patients with ongoing risk factors — injection drug use, men who have sex with men with high-risk sexual practices, hemodialysis — should be re-screened at least annually. Harm reduction including needle exchange, naloxone access, and medication for opioid use disorder substantially reduces both reinfection and overall mortality. Patients with significant fibrosis or cirrhosis at the time of cure remain at elevated risk of hepatocellular carcinoma and should continue six-month ultrasound surveillance per AASLD guidance. Vaccination against hepatitis A and hepatitis B, if not already immune, is recommended. Lifestyle changes that reduce continued liver injury — alcohol moderation or abstinence, weight management, control of diabetes and dyslipidemia — preserve the gains from successful HCV treatment.

When to Contact Your Doctor

Report new yellowing of skin or eyes, dark urine, right upper-quadrant pain, severe fatigue, nausea or vomiting that prevents taking doses, or unexplained bruising. Patients with prior HBV exposure should report any flu-like illness or jaundice promptly so HBV reactivation can be evaluated and treated. Severe rash, swelling, or wheezing is uncommon with oral DAAs but warrants immediate care. Any new prescription, over-the-counter medication, or supplement should be reviewed for interactions before starting.

HCV is curable for the vast majority of patients today, and treatment dramatically reduces the risk of cirrhosis, liver cancer, and the systemic complications of chronic infection. If you are living with hepatitis C or have not yet been screened, contact us or schedule a visit to review your eligibility for treatment, arrange the necessary baseline labs, and coordinate care with hepatology when needed.