Aino GS-441524 Manufacturer's Instructions

AINO INJECTIONS

Aino Red is available in 20mg/ml concentration. Each vial contains 10ml of the antiviral GS-441524.

DOSING GUIDE

Manufacturer’s recommended starting dosages for Aino Red Injectables (20mg/ml concentration)

All dosages stated below are the MINIMUM. Please note that your veterinarian may increase the dosage as clinically appropriate.

SYSTEMIC FORMS:

  • Wet FIP (Abdominal Effusion): 6mg/kg SC q24h
  • Wet FIP (Pleural Effusion): 8mg/kg SC q24h
  • Dry FIP (complete loss of appetite, visible physical deterioration; may or may not have respiratory distress): 8mg/kg SC q24h
  • Wet or Dry FIP with severe and/or persistent anemia: 10mg/kg SC q24h

OCULAR:

Ocular FIP (cloudiness, change of eye color, presence of blood spots, glaucoma; may occur in one or both eyes): 10mg/kg SC q24h

* Higher doses are needed to achieve adequate drug levels across the blood-ocular barrier. Injections preferred for consistency.

NEUROLOGICAL:

Neurological FIP (stiffness, imbalance, tremors, seizures, difficulty walking, difficulty swallowing, paralysis, anisocoria, nystagmus, blindness, urinary/fecal incontinence) 10-15mg/kg SC q24h (depending on severity of condition)

*For Neurological cases, CNS penetration is limited. Injectables GS-441524 may be preferred than oral GS due to more reliable absorption and higher bioavailability, which is crucial for crossing the blood-brain barrier.

AINO TABLETS

Aino tablets are available in 25mg (blue) and 50mg (red) forms. Tablets may be combined to reach the most accurate 
        dose for your cat.

For example:
Half 25mg tablet + half 50mg tablet = 37.5mg
One 25mg tablet + one 50mg tablet = 75mg

Fasting for 1h prior to giving the tablets is strongly recommended for maximum absorption. Resume feeding 1h after tablet time.

Tablets are to be given direct to mouth. They can be halved but not crushed and mixed into meals.

If given with a small treat (such as paste treats like Ciao or a small amount of wet food) to entice the cat, make sure that the cat consumed the entire amount to avoid underdosing.

Water should be given to the cat immediately afterwards to ensure proper swallowing.


DOSING GUIDE for Aino Tablets (12 weeks | 84 days)
The 84-day treatment duration is based on the traditional treatment course established through early GS-441524 clinical studies and subsequent UC Davis/Dr Niels C Pedersen guidance.

Oral GS dosage is +2-5mg/kg from injection dosage (change of route lowers bioavailability) or higher, depending on your vet’s treatment plan.

For Neurological cases, 18-22mg/kg tablet dosage is recommended. To be administered once daily or divided into two doses, according to the attending veterinarian’s treatment plan.

* Brostoff T, Pires J, Rose A, Cohen-Davidyan T, Castillo D, Murphy BG, Reagan KL. Treatment of non-effusive feline infectious peritonitis using oral remdesivir or GS-441524: A randomized, double-blind, non-inferiority trial. J Feline Med Surg. 2026;28(4):1098612X261433057. doi:10.1177/1098612X261433057. [https://pubmed.ncbi.nlm.nih.gov/41781382/]

DOSING GUIDE for Aino Tablets (6 weeks | 42 days)

Based on ISFM/iCatCare recommendations as of July 2025

FIP Presentation GS-441524 Route GS-441524 Dose Frequency
Effusions, without neurological or ocular signs PO 15 mg/kg q24h, or split q12h
No effusions, without neurological or ocular signs PO 15 mg/kg q24h, or split q12h
Ocular signs present ± effusion PO 20 mg/kg q24h, or split q12h
Neurological signs present ± effusion PO 10 mg/kg q12h

Neurological FIP: 84-Day Treatment Recommended

While shorter treatment courses have been studied in FIP, the strongest evidence supporting a 42-day course comes from cats with effusive FIP, while evidence for shortened treatment in neurological FIP remains limited.

Because neurological FIP involves the central nervous system and carries additional challenges and relapse concerns, Aino takes a more conservative approach and recommends the traditional 84-day (12-week) treatment course for cats with neurological involvement, using either injectable or oral GS-441524.

This recommendation reflects both the available evidence and our experience managing FIP cases, including observing relapses following shorter treatment courses in some cats with neurological disease.

Additional Notes on Treatment

Administer Injections/oral GS consistently at approximately same time each day, or at the very least within the hour.

If injection time must be moved, you may move +/- two hours per day until the desired time is reached.

Once the appropriate dosage has been given, it is not recommended to decrease dosage at any point of the treatment to avoid viral resistance.

Significant reasons to raise dosage include:

  • Little to no improvement at current dosage in 4-5 days, provided there are no other issues to address (e.g. anemia, high bilirubin levels, concurrent conditions, etc. that may hinder treatment progress)
  • Failure of blood tests to improve
  • Poor activity levels
  • Failure of original clinical signs to disappear
  • Change in disease form to include ocular or neurological signs


The new dosage will depend on your vet’s assessment of your cat’s condition.

GENERAL TREATMENT REMINDERS

Weigh 1-2x/week and adjust dose accordingly to weight gain. Not recommended to weigh every day to avoid up and down dosing due to possible factors (e.g. cat has just eaten/drank water; cat weight on a full/empty stomach) which do not reflect real weight change.

Treatment duration may range from 6–12 weeks depending on the form of FIP, treatment response, and your veterinarian’s treatment plan. Cats with neurological involvement are generally recommended to complete an 84-day (12-week) course. Final bloodwork and veterinary assessment MUST BE DONE before treatment is discontinued.

Monitoring bloodwork is commonly done on Days 30 and 60. 

Shifting to Aino tablets will require your vet’s approval as we are following their treatment plan.

Recovery from FIP does not provide reliable sterilizing immunity against FCoV.

  • FCoV reinfection is common: Cats may temporarily clear or suppress FCoV, but immunity is incomplete and does not reliably prevent future infection.
  • Mutation risk: FIP arises when FCoV mutates inside the cat. Even if a cat recovers from FIP with GS-441524 treatment, they can still be reinfected with FCoV, which could mutate again.
  • No sterilizing immunity: Unlike some viruses where recovery confers lifelong protection, cats with FCoV don’t develop sterilizing immunity. Their immune system may reduce viral load but doesn’t prevent future infections.

In multi-cat environments, FCoV circulates persistently. Cats, often asymptomatic, may repeatedly shed and re-acquire the virus, making eradication difficult.

What should you do?

FOCUS ON PREVENTION.

  • Regularly bleach or use vet-grade cleaners (GPC8, etc.) to clean your home.
  • Proper litter box management: Maximum of 3 cats per litterbox, and make sure to change the litter regularly, as FECES is the MAIN MODE of TRANSMISSION (fecal-oral route) of the Feline Coronavirus.
  • Reduce stress.