Remdesivir (RDV) is an effective treatment for feline infectious peritonitis (FIP) and is not merely an alternative to GS-441524 — both agents are used sequentially or in combination, with survival rates of 81–86% at 84 days across protocols incorporating either or both drugs.Journal of Vete…+3
For remdesivir, the induction dosage is 10–15 mg/kg IV or SC q24h for 4 doses, followed by a maintenance dosage of 6–15 mg/kg SC q24h continued for at least 84 days total.Journal of Vete… In cases of re-emergent FIP or ocular/neurological involvement, escalation to 15–20 mg/kg q24h is recommended.Journal of Vete…+1 When transitioning from parenteral remdesivir to oral GS-441524, the maintenance dose of GS-441524 is 10–15 mg/kg PO q24h, continued to complete the 84-day course.Journal of Vete… Oral GS-441524 doses of 10–20 mg/kg/day for 84 days have also been used successfully as a standalone approach.Journal of Vete…
The two drugs are mechanistically linked rather than interchangeable in a strict sense. Remdesivir is a prodrug that undergoes rapid hydrolysis to GS-441524 as its principal circulating metabolite; GS-441524 is then phosphorylated intracellularly to the active triphosphate form that inhibits viral RNA synthesis.Journal of Vete…+1 After IV administration, conversion to GS-441524 is near-complete within minutes, providing consistent plasma exposure.Journal of Feli… Oral remdesivir achieves low and variable bioavailability of GS-441524, yet clinical outcomes with oral remdesivir remain favorable, suggesting plasma GS-441524 concentration is not a reliable surrogate for treatment efficacy.Journal of Feli…
Clinical response to treatment is rapid regardless of protocol. In cats treated with combinations of IV remdesivir, SC remdesivir, and oral GS-441524, clinical response was observed in 87.5% of cats at a median of 2 days.Journal of Vete… Remission by day 84 was achieved in 56% of cats in one cohort using remdesivir with or without transition to oral GS-441524, with an overall 6-month survival of 86%.Journal of Vete… When cats survived the first 3 days of treatment, 92.8% were alive and in clinical remission at 12 weeks.Journal of Vete…
Early mortality is the primary risk. Most deaths occur within the first week of starting treatment, with 66% of non-survivors dying within 3 days of initiation.Journal of Vete…+1 Excluding cats that died within 48 hours, survival from 48 hours to 6 months was 96%.Journal of Vete… Positive responses within the first 30 days are associated with better outcomes.Journal of Feli…
Ocular and neurological FIP requires higher dosing due to limited drug penetration through the blood-ocular and blood-brain barriers, with doses of up to 20 mg/kg/day recommended for these presentations.Journal of Vete… Of cats with concurrent ocular and neurological disease treated at higher doses, 80% recovered fully.Journal of Vete…
Adverse effects of remdesivir are mild — occasional injection site discomfort and skin irritation with SC administration are the primary concerns.Journal of Vete… SC remdesivir is frequently associated with pain on injection, which makes oral GS-441524 tablets the preferred first-line agent where legally available.Journal of Feli… Remdesivir remains appropriate where it is the only legally accessible nucleoside analogue, or in cats that cannot tolerate oral medication during initial treatment.Journal of Feli…
Markers of treatment success follow a temporal pattern: resolution of pyrexia, effusions, and presenting clinical signs predominates in the first half of treatment, while globulin normalization and continued body weight gain are the relevant endpoints in the latter half.Journal of Vete…
| Drug | Dose | Route | Survival at End of Treatment | Key Caveat |
|---|---|---|---|---|
| Remdesivir (induction) | 10–15 mg/kg q24h × 4 doses | IV or SC | — | Escalate to 15–20 mg/kg for ocular/neuro FIP Journal of Vete…+1 |
| Remdesivir (maintenance) | 6–15 mg/kg q24h ≥84 days | SC | 81–86% at 84 days Journal of Vete…+1 | Painful on SC injection; re-emergent FIP responds to 15–20 mg/kg Journal of Vete… |
| GS-441524 (oral, transition or standalone) | 10–20 mg/kg q24h × 84 days | PO | 81–86% at 84 days Journal of Vete…+1 | Preferred first-line where legally available Journal of Feli… |
| Oral remdesivir | Variable | PO | Favorable outcomes reported Journal of Feli… | Low and variable GS-441524 bioavailability; not a substitute for IV induction in critical cases Journal of Feli… |
Would you like guidance on monitoring parameters and when to escalate dosing during the 84-day treatment course?