Mechanism of Action

When GS-441524 is intracellularly triple-phosphorylated, its active analogue, 1′-cyano-substituted adenosine triphosphate, is produced. This analogue competes with endogenous NTPs to be incorporated into nascent viral RNA transcripts and causes delayed chain termination of RNA-dependent RNA polymerase. This directly disrupts viral RNA replication.[4]

Benefits and Advantages

FIP had no known cure until recently, but GS-441524, an antiviral drug, is now available and works well to treat the illness. Numerous nations offer GS-441524, which has been shown to be both safe and effective.

The current guidelines suggest treating cats for 12 weeks in order to fully remove the illness and maximise their chances of recovery. As therapies progress, shorter courses might be suggested in the future. Antiviral medicine dosages vary depending on the kind of FIP; cats with neurological and/or ocular FIP are typically prescribed greater dosages.

The treatment with GS-441524 has remarkably few systemic side effects.

Side Effects and Risks

It’s crucial to remember that different cats react differently to treatment, and that results can differ from person to person. It is essential to conduct ongoing assessments of the cat’s condition, close observation, and routine veterinarian check-ups in order to determine the efficacy of the treatment and make any required modifications.

Deciding when to cease treatment is one of the hardest decisions. The typical course of treatment lasts 12 weeks, although some cats—typically younger ones with wet FIP—can be healed in as short as 8 weeks, if not sooner. It’s possible that certain cats will even need lengthier treatment times and dose modifications. In cats destined for cures, critical blood parameters including haematocrit, total protein, albumin and globulin levels, and absolute lymphocyte counts typically return to normal around 8–10 weeks, at which point there is frequently an unexpected rise in activity levels. The cat’s own immunity to the illness is thought to develop between 8 and 10 weeks in, though this is not confirmed. 

Pain at the injection sites is the main side effect of GS treatment, and it varies from cat to cat and depending on how skilled the person administering the treatment is with injections (typically the owner). Some owners have injection site sores, which mainly happen when the injection site is not moved about the body (avoid the area between the shoulders) or administered into the layers of muscle and nerve beneath the subcutis. I advise choosing locations that are one inch below the shoulder blades, one third to half of the way down the chest and abdomen, and down the back to 1-2 inches before the tailhead. Before receiving an injection, gabapentin is frequently used to reduce pain.

In certain cats, it may result in mild kidney damage; however, overt renal illness does not develop from this. 

Our GS-441524 is produced in a GMP facility. Several veterinary institutes in Europe use our raw materials with excellent results. References are available upon request.