Stokes Pharmacy’s exclusive partnership with the Bova Group to bring safe, compounded treatment for feline infectious peritonitis (FIP) to the US brought a lot of excitement for veterinarians and pet owners looking to save cats with FIP.
Not having access to treatment previously, Stokes’ release of Bova GS-441524 tablets was the first FIP treatment available in the US, with the release of EIDD-1931 following for additional treatment options. As with any new treatment option though, there are questions.
To help you cut through all the stories you’re reading and announcements you’re hearing, Dr. Samantha Taylor, BVetMed(Hons) CertSAM DipECVIM-CA MANZCVS FRCVS, has answered the top FIP frequently asked questions we’ve heard from veterinarians and pet owners.
Sam is an RCVS Recognized Specialist in Feline Medicine, a European Specialist in Veterinary Internal Medicine, and a Fellow of the RCVS. Sam was involved in the launch of legal medications in the UK and set up the FIP advice email service with other specialists, which has answered nearly 3000 emails about the novel FIP treatments from around the world. In 2023 she published a report on over 300 cats treated for FIP and continues to be involved in FIP research.
Check out her answers below and get the peace of mind you need to treat your patients or care for your pet.
Vet Questions about GS-441524
Can I legally prescribe this drug in the US?
The FDA’s Center for Veterinary Medicine (CVM) has notified veterinarians that compounded Bova GS-441524 from Stokes Pharmacy falls under Guidance For Industry (GFI) #256 and is allowed to be compounded and legally prescribed. Read the CVM’s statement here.
Is this the same GS-441524 that’s on the black market?
No, unlike black market products, this GS-441524 product from Stokes Pharmacy contains a known amount of the antiviral using the Bova formulation that has been studied in three peer-reviewed publications to date. This means when prescribing, you can be confident about the recommended dosing.
Is GS-441524 absorbed from the gut when given orally?
The published studies and extensive experience in other countries using this formulation of oral GS-441524 has shown cats respond well to oral GS-441524 treatment, and 85% or more respond completely.
Should cats with FIP start on injections first and then switch to tablets?
The vast majority of cats can be treated with oral GS-441524 from day 1. The exceptions are those severely unwell cats that have reduced mentation or cannot swallow, which thankfully are only a very small proportion of cases. Therefore, it is no longer recommended or necessary to start with injections for most cats with FIP, whatever the form.
Should veterinarians dose our tablets based on black market dosing or whatever medication they may have been getting before?
No, the current dosage advice is based on publications and clinical experience from multiple countries using the regulated formulations of Bova GS-441524 to treat what is now thousands of cats with FIP. The content of GS-441524 in black market products has been shown to vary, but the regulated formulation has a known amount of Bova GS-441524 which should be given according to recommendations.
Are molnupiravir or (active form of molnupiravir) an equivalent treatment to GS-441524 or do I start cats with GS tablets?
Bova GS-441524 is currently the preferred first choice based on the number of published studies suggesting it is slightly more effective with fewer adverse effects. Additionally, molnupiravir and EIDD-1931 carry concerns around caregiver handling of medication due to teratogenicity. In parts of the world with more than one treatment option, molnupiravir and EIDD-1931 are useful as second-line therapy for relapsed or poorly responsive cats, and as such, it is ideal to have these additional antivirals legally available.
Vet & Pet Owner Questions about FIP Treatment
Is there a minimum age or minimum weight that the cat has to be to receive this treatment?
Many young kittens have been successfully treated, although we await more studies including all ages of cats to learn more. Dosages are by weight so a small kitten would be treated with a smaller amount of medication that is then increased as the kitten grows and gains weight.
How often do cats need to be monitored while on this medication?
This will vary according to the individual case, but initial improvement should be seen within 48 hours when contact with caregivers is encouraged to check on progress and for any problems giving medications. After this, frequency of re-checks will depend on response and monitoring should be adequate to assess response but, particularly when the cat is doing well, repetition of costly testing and multiple stressful clinic visits should be limited. Caregiver should be encouraged to weigh their cat at home and keep a diary of appetite and demeanour and other parameters such as respiratory rate as indicated. Generally, checks at 2 weeks, 6 weeks and before stopping at 12 weeks are recommended, if stopping therapy at 6 weeks then additional checks at 2 and 4 weeks are recommended.
How often does the medication need to be administered? Is it once every 12 hours or once a day?
Research studies are currently underway to learn more about this aspect, but most cats can be successfully treated once a day. However, if response is not as expected, the dose should be divided to give every 12 hours.
Can the medication be crushed and given in food or a treat?
Yes, it’s recommended to give the medication in a small treat or small amount of food. However, it can be easier to give tablets if the cat is hungry so a period without food (if fasting is appropriate for the age, as kittens need to eat often) before giving the tablet in a treat (crushed if needed) can facilitate acceptance of medication. Avoid mixing medication with main meals as it can be hard to tell if it has been eaten.
Are there any side effects or adverse effects?
The medications are safe and well tolerated. GS-441524 can cause some changes in blood test results (elevated eosinophils, lymphocytes and a liver enzyme, ALT) that resolve once treatment is complete. Uroliths of GS-441524 have been reported rarely, but not with the legal preparations. At high dosages, it is prudent to increase water intake and investigate any urinary signs.
When should caregivers start seeing improvement in their cat’s symptoms on the medication?
Improvements are generally rapid and within 2-5 days caregivers should notice an improvement in demeanor, appetite, resolution of pyrexia, and reduction in abdominal or pleural fluid if present. Note that pleural effusion can require repeat drainage during initial treatment as treatment takes effect. If predicted improvements are not seen, and the diagnosis is reliable, then the dosage may need to increase.
Pet Owner Questions about FIP & Treatment Plans
What are the signs my cat has FIP?
Cats with FIP can show in a variety of ways as the disease can affect any organ in the body. The most common signs are lethargy/tiredness, eating less and losing weight, and a high temperature. Cats may have a swollen belly due to fluid, neurological signs (fits, wobbly walk or changes in behavior), eye problems, or trouble breathing. FIP can look like many other conditions, so tests are needed to confirm the diagnosis.
If I have other cats in the household, do I need to treat those as well?
We only treat cats diagnosed with FIP with antivirals. Generally, only one cat in a home will be affected, although occasionally related cats and housemates can develop FIP as well. The health of in-contact cats should be monitored but we must reserve medications for cats with the disease because treating cats without FIP could risk medication becoming less effective longer term.
Why should I buy Bova GS-441524 from Stokes instead of the black market?
No one knows what is in the black market drugs as they are unknown, untested drugs made following no regulations. Tests have shown black market drugs contain variable amounts of medication so choosing how much to give becomes very difficult and inaccurate. Some products could even cause illness due to acidic formulations for example. Read more about black market FIP drugs and their risks in this clinical study.
Stokes Pharmacy is selling the only oral formula identical to the Bova formula used in clinical studies across the globe. The Stokes Pharmacy product is tested against Bova’s proven standard and compounded by a leading regulated nationwide compounding pharmacy. Testing against a standard ensures that a drug meets the required criteria for consistency throughout its lifecycle, from raw material to finished product. These standards ensure that the drug delivers consistent therapeutic benefits to patients. Veterinarians can prescribe with confidence knowing that Bova’s treatments will perform consistently. This also reduces the overall costs associated with treatment failures, side effects and long-term patient care, making it one of the most cost-effective options for veterinarians when treating cats with FIP.
Your beloved pet should be under the care of a licensed veterinarian to guide you through FIP treatment. Like other antivirals, Bova GS-441524 should be prescribed by a veterinarian for reasons that include the risk of antimicrobial resistance.
Explore more of our FIP resources.
Veterinary FIP Resources
Cat Owner FIP Resources
1. Coggins, S. J., Norris, J. M., Malik, R., Govendir, M., Hall, E. J., Kimble, B., & Thompson, M. F. (2023). Outcomes of treatment of cats with feline infectious peritonitis using parenterally administered remdesivir, with or without transition to orally administered gs‐441524. Journal of Veterinary Internal Medicine, 37(5), 1772–1783. https://doi.org/10.1111/jvim.16803
