Pharmacologic class (EPC) · 3 drug pages

Hepatitis C virus NS3/4A protease inhibitor: adverse event reports filed with FDA

15,916 reports list a drug in this class as a suspect or interacting product, 2016–2026.

Read first · FDA's statement on these data

Adverse event reports submitted to FDA do not undergo extensive validation or verification. Therefore, a causal relationship cannot be established between product and reactions listed in a report. While a suspected relationship may exist, it is not medically validated and should not be the sole source of information for clinical decision making or other assumptions about the safety or efficacy of a product. Additionally, it is important to remember that adverse event reports represent a small percentage of total usage numbers of a product. Common products may have a higher number of adverse events due to the higher total number of people using the product. openFDA, FDA

FDA adds: "There is no certainty that the reported event (adverse event or medication error) was actually due to the product. FDA does not require that a causal relationship between a product and event be proven, and reports do not always contain enough detail to properly evaluate an event." The information in these reports "cannot be used to estimate the incidence of these events."

Do not rely on openFDA to make decisions regarding medical care. While we make every effort to ensure that data is accurate, you should assume all results are unvalidated.

Not medical advice. This site counts what was reported to FDA. Questions about a medicine or device belong with a pharmacist or clinician.

15,916
reports across the class: 0.1% of all reports; 268
reports, 12 months to June 2026: 301 in the 12 months before; 27.5%
marked serious by the reporter: 57.4% across all reports; 3
drugs with a page: brand and generic names counted separately

Hepatitis C virus NS3/4A protease inhibitor is a pharmacologic class (an FDA Established Pharmacologic Class) with 3 drug pages on this site. Together those drugs are listed as a suspect or interacting product in 15,916 adverse event reports received by FDA, 0.1% of the database, from February 2016 to June 2026.

268 reports arrived in the 12 months to June 2026, down 11% from 301 in the 12 months before. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases. 27.5% of the class's reports are marked serious, 2.7% record death among the outcomes and 11.8% record hospitalisation, as reported.

Across the class the reactions recorded most often are fatigue (23%), headache (19%) and nausea (10.5%). The class median share shown beside each term is the middle value across the member drugs; it is the comparison used on every drug page in this class.

The members table is ordered by report count for navigation only. FDA states that adverse event reports "represent a small percentage of total usage numbers of a product", that "common products may have a higher number of adverse events due to the higher total number of people using the product", and that the data "by themselves are not an indicator of the safety profile of the drug or biologic."

Drugs in the class

Drug	Name type	Reports	Latest 12 months	Marked serious	Top term recorded
MavyretGlecaprevir and pibrentasvir	brand	10,790	227	25.3%	Fatigue
ZepatierElbasvir and grazoprevir	brand	4,072	10	31.2%	Fatigue
VoseviSofosbuvir, velpatasvir, and voxilaprevir	brand	1,054	31	36.5%	Fatigue

Ordered by report count for navigation only. FDA states that adverse event reports "represent a small percentage of total usage numbers of a product", that "common products may have a higher number of adverse events due to the higher total number of people using the product", and that the data "by themselves are not an indicator of the safety profile of the drug or biologic."

Reports by month, five years

FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases.

Reactions recorded across the class

share of class reports recording the termmedian drug in the class

Fatiguetiredness23%3,661
Headachehead pain19%3,031
Nauseafeeling sick10.5%1,675
Diarrhoealoose or frequent stools5.1%808
Pruritusitching4.8%757
Vomitingbeing sick3%478
Insomniadifficulty sleeping2.6%413
Drug dose omissiona dose was missed2.5%400
Rashskin rash2.4%384
Dizzinesslight-headedness or unsteadiness2.2%353
Drug ineffectivethe medicine did not work as expected2.2%345
Deaththe patient died; cause not stated by this term1.9%307
Abdominal discomfortstomach discomfort1.9%297
Painpain, site not specified1.8%288
Hepatitis Chepatitis C infection1.8%287
Abdominal pain upperupper stomach pain1.5%245
Astheniaweakness or lack of energy1.5%244
Decreased appetitereduced appetite1.5%239
Constipationconstipation1.5%237
Dyspnoeashortness of breath1.4%229
Treatment failurethe treatment did not work1.4%226
Arthralgiajoint pain1.4%220
Abdominal painstomach or belly pain1.4%216
Depressionlow mood1.1%178
Therapy cessation1.1%170

Solid bar: share of all class reports. Hollow bar: the median share across the 3 member drugs, the reference used on each member's page. One report can record several terms.

Outcomes, patients and reporters

Outcomes recorded

Death2.7%437

Life-threatening0.7%105

Hospitalisation (initial or prolonged)11.8%1,877

Disability0.6%94

Congenital anomaly0.1%9

Other serious16.6%2,640

Not serious72.5%11,535

Patient age

Under 20.1%8

2 to 110%5

12 to 170%7

18 to 4416.9%2,697

45 to 6441.7%6,639

65 to 7410.4%1,652

75 and over1.8%279

Age not given29.1%4,629

Who reported

Physician9.2%1,468

Pharmacist30%4,772

Other health professional20.7%3,293

Lawyer0%4

Consumer or non-health professional28.7%4,561

Not given11.4%1,818

Grey bar: all 20,646,523 reports in the database. Outcome flags are as the reporter set them and are not verified by FDA.

Questions about Hepatitis C virus NS3/4A protease inhibitor reports

Which drugs are in the Hepatitis C virus NS3/4A protease inhibitor class on this site?

Mavyret, Zepatier and Vosevi. Class membership comes from the pharmacologic class (EPC) on the drug's FDA label.

How many reports does the class have?

15,916 reports through June 2026, 268 of them in the latest 12 months. A report listing two drugs of the class counts once for each.

What reactions are recorded most often?

fatigue (23%), headache (19%), nausea (10.5%), diarrhoea (5.1%) and pruritus (4.8%).

Can the members table be used to rank the drugs?

No. FDA states that adverse event reports "represent a small percentage of total usage numbers of a product", that "common products may have a higher number of adverse events due to the higher total number of people using the product", and that the data "by themselves are not an indicator of the safety profile of the drug or biologic." Drugs differ in how many people take them, in the conditions they treat, in time on the market and in how diligently reports are collected.

How do I report an adverse event?

Through FDA MedWatch (Form FDA 3500, or 1-800-FDA-1088) or to the manufacturer. See the guide on how to report.

Where this comes from. Counts are built from the openFDA Drug Adverse Event (FAERS) bulk export released 28 Sep 2026, which holds reports FDA received through 30 Jun 2026. Drug names are as reported, resolved to the brand or generic name on the FDA label where openFDA's harmonisation matched them; classes are the pharmacologic class (EPC) from the label and the National Drug Code Directory of 17 Sep 2026. A class is the Established Pharmacologic Class most often attached to a drug's reports by openFDA's label harmonisation, or from the NDC Directory where reports carry none. No report narrative, lot number, patient detail or reporter identity is published. See the methodology and sources; FDA's record is authoritative, and corrections are handled within five working days.

Drug data (FAERS) through 30 Jun 2026; device data (MAUDE) through 31 Aug 2026. Not medical advice.