Cat FIP Treatment: Medical Advancement for FIP saves cats
A proven cat FIP treatment is already available for cats. However, due to a lack of financial motivation, there is currently no listed medication for FIP in cats that has been officially approved. Supportive therapy can ease discomfort but won’t increase survival rates, such as anti-inflammatory drugs and fluid drainage from the chest and abdomen. Euthanasia has been the best option in the past given the disease’s quick and high mortality rate, but today treatment can be provided with a high rate of success.
There are a few investigational medications being investigated right now, including GS441524, GC376, CL-Pro and Remdesivir. These medications are not currently legally accessible for clinical use for cats.
ANTIVIRALS (Protease Inhibitors, Polymerase Inhibitors, Nucleoside Analogues)
The only treatments that now give hope to cats with FIP are GS441524 which is a nucleoside analogue, and GC376, a protease inhibitor.
GS441524 remains the best option for treating FIP due to its lower relapse rates compared to GC376. It is also faster acting compared to Remdesivir. In fact, Remdesivir is a pre-cursor to GS441524, so it takes an extra step for Remdesivir to be converted into GS441524 for it to work.
GS-441524
Evidence has been provided that this medication works well in numerous situations. Getting it has been difficult. Remdesivir, as previously stated, is the protide or prodrug that the body subsequently transforms into GS-441524. Giving the medication in its protide or prodrug form aids in getting it into the immune system cells that contain immunosuppressive coronaviruses. In some drug’s cat testing, GS-441524 was given in its original formulation with no successful FIP cure rates seen.
GS441524 is still our best option for treatment currently. However, due to the high cost and lack of access to this medication, cat owners should be more pressed to prevent their cat from catching the disease in the first place.
GC376
GC376 can be considered as a broad-spectrum antiviral drug that inhibits Mpro of several viruses, including the coronaviruses like FCoV, porcine epidemic diarrhoea virus (PEDV), SARS-CoV, MERS-CoV, SARS-CoV-2, ferret, and mink coronavirus. GC376 is the prodrug of GC373, another dipeptide-based protease inhibitor.
Treatment of FIP in cats with GC376 was associated with side effects such as transient stinging at the injection sites, subcutaneous fibrosis, hair loss, and abnormal eruption of permanent teeth in juvenile cats [4]. Therefore, further studies are required to evaluate the possible side effects associated with the use of GC376 in animal models, before its use in clinical trials.
GC376 prevents the replication of FCoV virus with a different mechanism. However, the relapse rate in cats treated with GC376 is significantly higher than GS441524. Where GC376 shines is when cats developed a resistance towards GS441524, especially in relapse cases. Then it is advisable to use GC376 instead.
There are also research studies that show a combination of both GS441524 and GC376 yields better results and also allowed for a shorter duration of 6 weeks of treatment instead of the usual 12 weeks.
Feline Interferon
Interferon is what the body naturally makes in response to a virus infection. There are two kinds of interferons available to veterinary surgeons: feline interferon omega (Virbagen Omega,® made by Virbac in France) and human interferon alpha, which comes under a few brand names. It is preferable to use feline interferon, because interferons are species specific: they work best in the species of origin.
Interferon-omega is an injection marketed for cats with FIP. A small early study showed promising results and so for a brief period it became part of the standard treatment. It was one of the earliest treatment available for FIP, however, the success rate was low.
A larger double-blinded placebo-controlled study found no benefit to interferon. That should have been the end of the matter, but the drug is still available, and people still push the earlier paper without reference to the later one.
CORTICOSTEROIDS (ONLY FOR PALLIALITIVE)
During the early illness, supportive (symptomatic) medication may be required to keep cats alive long enough for antivirals to take action. Anti-inflammatories are frequently included in the medications (corticosteroids, NSAIDS). It is preferable to avoid using these medications excessively, unless on a short basis and only if there is a compelling rationale for doing so, especially in extremely unwell cats over the first few days.
The primary objective of treating FIP is to prevent viral replication in macrophages, which will instantly stop the generation of the various inflammatory and immunosuppressive cytokines that produce FIP symptoms. While certain medications, such as corticosteroids (prednisolone) and NSAIDS (meloxicam), may reduce inflammatory cytokines, GS-441524 totally block these damaging cytokines. Within 24-48 hours, FipMed will induce significant improvements in temperature, activity, hunger, and other symptoms. This improvement will be significantly greater than any other drug can provide. As a result, unless there is a compelling reason to continue using other medications, they should be discontinued as soon as there is a noticeable and consistent improvement in FIP symptoms.
In addition to masking FIP-related symptoms, steroids may interfere with the distribution of GS-441524 through the blood-brain barrier. Several investigations have demonstrated that steroids can reduce permeability across the blood-brain barrier. In cats, decreased permeability may reduce the efficiency of GS-441524 and raise the likelihood of relapse.
GS 441524 Safety as FIP Treatment
GS-441524 has been shown to be a safe and effective treatment option. The drug was originally developed as an antiviral treatment for humans but has since been repurposed for feline use.
Multiple studies have demonstrated that the drug does not cause significant adverse effects or toxicity when administered as directed.
Some cats may experience mild side effects such as nausea or lethargy during treatment. These symptoms typically resolve quickly and do not require intervention from a veterinarian.