HerpX™ delivers 180 mg of famciclovir in small coated tablets sized for weight based dosing in cats. It gives owners a practical alternative to splitting human cold sore tablets when a cat is in the middle of a Feline Herpesvirus (FHV-1) flare.
Built for cats, not adapted from human medicine
Famciclovir is a prodrug of penciclovir, a nucleoside analogue with demonstrated activity against Feline Herpesvirus (FHV-1). It is regarded as systemically safe in cats when dosed appropriately, which is an important distinction from acyclovir and valacyclovir, human antivirals associated with toxicity in cats. HerpX™ is intended for feline use under veterinary guidance only.
Supported by published feline research
Famciclovir use in cats is backed by a body of published feline pharmacokinetic and clinical work, including dose optimisation modelling and a 59 case clinical series covering ocular, respiratory and dermatologic disease attributed to Feline Herpesvirus (FHV-1). That evidence base informs the widely cited dosing approach of approximately 90 mg/kg every 12 hours used under veterinary direction.
Where HerpX™ is used
- Ocular flares, including conjunctivitis and corneal disease
- Upper respiratory flares, including sneezing, nasal discharge and congestion
- Recurrent flares triggered by stress
A note worth reading
Feline Herpesvirus (FHV-1) stays in the body after the first infection and can flare again when a cat is stressed, unwell or in a new environment. Treatment is about controlling flares and protecting your cat's eyes and comfort, and many cats need a plan for managing recurrences rather than a single course.
HerpX™ 180 mg Antiviral Tablets for Feline Herpesvirus (FHV-1)
Famciclovir is dosed by body weight at approximately 90 mg/kg every 12 hours, the approach supported by published feline studies. The exact dose depends on your cat's weight and your veterinarian's assessment, so confirm the number of 180 mg tablets per dose with your veterinarian.
Indicative guide, to be confirmed with your veterinarian:
- Cat around 2 kg: approximately 180 mg per dose, 1 tablet, every 12 hours
- Cat around 4 kg: approximately 360 mg per dose, 2 tablets, every 12 hours
- Cat around 6 kg: approximately 540 mg per dose, 3 tablets, every 12 hours
Monitoring: ongoing veterinary review during treatment is recommended so your veterinarian can assess the response and decide on continuation or adjustment. Do not taper or reduce antiviral dosing without veterinary direction.
Length of treatment: continue until signs have resolved, or as directed by your veterinarian.