Research overview: molnupiravir as a rescue therapy for FIP

Molnupiravir, a nucleoside analog that induces lethal mutagenesis in RNA viruses, emerged as an oral option for FIP, particularly as a rescue therapy for cats that relapse or respond poorly to GS-441524-based treatment. Clinical reports describe its use to achieve remission in difficult cases, though attention to dosing and potential toxicity is emphasized. This overview compiles clinical experience and the treatment literature rather than one source, describing its distinct mechanism compared with chain-terminating analogs and protease inhibitors, why having multiple antiviral classes matters for managing resistant or relapsing disease, and how the expanding pharmacologic toolkit has further consolidated the transformation of FIP from a uniformly fatal diagnosis into a frequently curable one.