We offer FIPMed EIDD2801 capsules for cats that have developed resistance to GS441524 and it no longer works for them. In that case, EIDD2801 can be a last resort. 

Molnupiravir (EIDD-2801) shows high toxicity, making it unsuitable for the long-term use required in FIP treatment. Prolonged use can lead to RNA mutations, increasing the risk of cancer.

Molnupiravir is only appropriate for short-term treatments like COVID-19, where a 5-day course isn’t long enough to cause harmful mutagenic effects.

FIP cats treated with Molnupiravir or EIDD2801 might have increased chance of getting cancer within 3 years’ time. It is not recommended to treat FIP with EIDD2801, particularly for young cats.

It is only an alternative if your cat does not respond to GS441524 any longer.

Why does FIP treatment need to last 84 days? The FIPV virus remains in the cat’s body for up to 90 days. Antivirals like GS-441524, Molnupiravir, and GC376 inhibit virus replication rather than killing the virus directly, so we must wait for the virus to die naturally. There is currently no drug in the market to kill the virus successfully to shorten the treatment time.