EIDD-1931 (NHC) Oral Tablets

Product Name: EIDD-1931 (NHC) Oral Tablets
Strength: 60 mg / tablet
Indications:
For the treatment of naturally occurring feline infectious peritonitis (FIP) in cats, including:
Effusive (wet) FIP
Non-effusive (dry) FIP
FIP with neurological involvement
According to clinical studies, EIDD-1931 administered at 15–20 mg/kg PO q12h for 12 weeks is a feasible treatment option for naturally occurring FIP
Active Ingredient
EIDD-1931 (β-D-N⁴-hydroxycytidine; NHC) – A nucleoside analogue antiviral agent that inhibits feline
coronavirus (FCoV) replication 
Dosage and Administration
For Cats Only

Indication	Route	Dosage	Frequency
FIP Treatment	Oral (PO)	12.5 – 20 mg/kg	Every 12 hours (twice daily)

Dosage Table – 60mg Tablets

Body Weight (kg)	Dose per Administration	60mg Tablet Count	60mg Tablet Count
2.0 – 2.5	25 – 50	1/2 – 1	12.5 – 20.0
2.6 – 3.0	32.5 – 60	1/2 – 1	12.5 – 20.0
3.1 – 3.5	38.75 – 70	3/4 – 1 + 1/4	12.5 – 20.0
3.6 – 4.0	45 – 80	3/4 – 1 + 1/3	12.5 – 20.0
4.1 – 4.5	51.25 – 90	1 – 1.5	12.5 – 20.0
4.6 – 5.0	57.5 – 100	1 – 1.75	12.5 – 20.0
5.1 – 5.5	63.75 – 110	1 – 2	12.5 – 20.0
5.6 – 6.0	70 – 120	1 – 2	12.5 – 20.0
> 6.0	Calculate by weight	Use combination as	12.5 – 20.0

Administration Instructions
1.Administer orally with or without food
2.Tablets may be given whole or crushed and mixed with a small amount of food 3.Oral solution should be measured accurately using the provided dosing syringe
4.Administer every 12 hours (twice daily) for a minimum of 12 weeks
5.Do not skip doses to ensure optimal therapeutic effect

Precautions
1.This is a prescription drug and must be used under veterinary supervision
2.Monitor complete blood count (CBC) and liver enzymes (ALT) during treatment
3.Discontinue treatment if severe neutropenia or persistent ALT elevation occurs
4.Not recommended for use in pregnant or lactating cats (safety not established)
5.Keep out of reach of children
6.For animal use only

Mechanism of Action
EIDD-1931 (NHC) is the active nucleoside form of the prodrug molnupiravir (EIDD-2801). It acts as a
potent inhibitor of feline coronavirus (FCoV) replication by inducing lethal mutagenesis during viral RNA
synthesis. Studies have confirmed its effectiveness against both FIPV serotypes I and II in vitro . Plasma
levels sufficient to inhibit viral replication are achieved following oral administration .

Treatment Response
According to clinical studies (Kennedy et al., 2026):
All cats (9/9) with naturally occurring FIP showed a complete response to treatment
Response observed in both effusive and non-effusive forms, including neurological involvement
Median dose of 16.2 mg/kg (range 12.0–20.5 mg/kg) administered PO q12h for 12 weeks
Treatment success sustained for >12 months post-discontinuation in most cats

Drug Interactions
EIDD-1931 may influence CYP3A4 and CYP2C8 enzyme activity
Caution should be exercised when co-administered with other medications metabolized by these pathways Potential for disease-state dependent pharmacokinetic alterations

Note on Pharmacokinetics
EIDD-1931 is the active metabolite of the prodrug molnupiravir (EIDD-2801). Oral administration
of EIDD-1931 achieves plasma levels greater than the EC₅₀ values established for FIPV inhibition
in vitro . Disease states such as liver injury or gastric injury may affect drug exposure and
clearance, potentially requiring dose adjustment

Package:
Tablets: Aluminum-plastic blister pack, 10 tablets per blister
Storage:
Store at controlled room temperature 20° to 25°C (68° to 77°F). Protect from freezing. Use contents
within 90 days of first puncture.
Shelf life:
2 years

For animal use only.