Nirmatrelvir

Nirmatrelvir is an antiviral drug currently under development by Pfizer for the treatment of COVID-19. It is a part of a combination therapy with Ritonavir, another antiviral drug, and is being marketed under the brand name Paxlovid.

Mechanism of Action[edit | edit source]

Nirmatrelvir works by inhibiting the main protease (Mpro) of the SARS-CoV-2 virus. Mpro is an essential enzyme for the virus, playing a crucial role in mediating viral replication and transcription processes. By inhibiting this enzyme, Nirmatrelvir prevents the virus from multiplying within the host's body.

Development and Approval[edit | edit source]

The development of Nirmatrelvir began in early 2020, shortly after the onset of the COVID-19 pandemic. Pfizer utilized a structure-based drug design approach to develop this novel antiviral. In November 2021, Pfizer applied for Emergency Use Authorization (EUA) from the U.S. Food and Drug Administration (FDA) for Nirmatrelvir in combination with Ritonavir for the treatment of mild-to-moderate COVID-19 in individuals at high risk of progressing to severe disease.

Clinical Trials[edit | edit source]

Several clinical trials have been conducted to evaluate the safety and efficacy of Nirmatrelvir. The most notable of these is the EPIC-HR trial, a Phase 2/3 randomized, double-blind, placebo-controlled trial. The trial demonstrated a significant reduction in the risk of hospitalization or death in patients treated with Nirmatrelvir and Ritonavir compared to placebo.

Side Effects[edit | edit source]

Common side effects of Nirmatrelvir include nausea, diarrhea, and vomiting. Serious side effects are rare but can include hepatotoxicity and severe allergic reactions.