PTCB DRUG CLASS
-vir

Antivirals

Antibiotics don't work here

Every generic name in this class ends in -vir. Viral infections — cold sores, shingles, genital herpes and COVID-19.

Blocks a step the virus needs to copy itself.

The 3 antivirals in the PTCB Top 200

Generic Brand Common use
ValacyclovirValtrexherpes (HSV, shingles)
AcyclovirZoviraxherpes (HSV, VZV)
Nirmatrelvir / RitonavirPaxlovidCOVID-19 (mild-moderate)

Tap any generic name for its full drug guide — brand↔generic, side effects, interactions and the exam tip.

What to know for the exam

health_and_safety Safety

Nirmatrelvir/ritonavir has an unusually long interaction list — every profile needs a full check before dispensing.

workspace_premium PTCE exam tip

Antibiotics do not treat viral illness. That distinction shows up regularly in scenario questions.

RxReflex app icon

Drill antivirals the way the PTCE asks them

RxReflex groups the Top 200 drugs into classes like this one, then quizzes you on brand↔generic, class, side effects and interactions. Plus a guided Learn path, pharmacy math and 40+ cheat sheets. Free to start.

Frequently asked

What does the suffix -vir mean? add

A generic drug name ending in -vir identifies it as one of the antivirals. Viral infections — cold sores, shingles, genital herpes and COVID-19.

What drugs are in the antivirals class? add

Valacyclovir, Acyclovir, Nirmatrelvir / Ritonavir. All are in the PTCB Top 200.

What are antivirals used for? add

Viral infections — cold sores, shingles, genital herpes and COVID-19.

How do antivirals work? add

Blocks a step the virus needs to copy itself.

Last reviewed August 7, 2026. For education only — not medical advice. Not affiliated with or endorsed by the PTCB.