Another Treatment Option for Cats With FIP: Molnupiravir

Jim Budde, PharmD, RPh, DICVP, Chief Pharmacy Officer, Instinct Science

ArticleDecember 20241 min read
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Full drug information and a pet owner handout can be found at Plumb's.com.

Pharmacology of Molnupiravir

Molnupiravir is a prodrug that is metabolized to the cytidine nucleoside analogue N(4)-hydroxycytidine (NHC). Intracellularly, NHC is phosphorylated into the active triphosphate (NHC-TP), which is incorporated into FIP RNA, resulting in an accumulation of errors in the viral genome that leads to inhibition of viral replication.1 Molnupiravir and NHC have demonstrated potent antiviral activity against the FIP coronavirus.2,3

Contraindications of Molnupiravir 

Molnupiravir is contraindicated in cats hypersensitive to it. This drug is not recommended for use in cats that are pregnant or lactating. 

Adverse Effects of Molnupiravir

Molnupiravir appears to be well tolerated. Adverse GI effects (eg, hypersalivation, nausea, vomiting, reduced appetite) have been reported.3,4 

Additional Information & Administration Instructions 

Molnupiravir is not approved for use in cats but may be available from compounding pharmacies. A comprehensive look at how to manage FIP is offered by the experts at Plumb’s (paid subscription only).

Important updates for use of GS-441524 & remdesivir to treat cats with FIP are also available.