HerpX™ 180 mg | Feline herpesvirus (FHV-1) antiviral
HerpX™ contains famciclovir, the oral antiviral with the strongest clinical support for feline herpesvirus (FHV-1), in fixed-dose tablets formulated for cats. Each tablet provides 180 mg of famciclovir, which allows the dose to be matched to your cat's weight without splitting human tablets.
About feline herpesvirus (FHV-1)
Feline herpesvirus, also known as feline viral rhinotracheitis, affects mainly the eyes and the upper respiratory tract. It causes conjunctivitis, corneal lesions, sneezing, nasal discharge and congestion. The eyes are this virus's characteristic target: if your cat is squinting, tearing more than usual or showing redness, see your veterinarian promptly. A corneal ulcer is an emergency.
The virus stays in the body
No treatment, famciclovir included, clears feline herpesvirus from the body. The virus remains latent in nerve tissue for the cat's lifetime. That does not mean signs always return: in many carriers they never reappear. Flare-ups are triggered by stress, other illness or treatments that lower immunity, and they are normal herpesvirus behaviour, not treatment failure.
What HerpX™ does is reduce viral replication and shedding during a flare-up, shorten the episode and protect the eyes.
An antiviral chosen for cats
Famciclovir is considered systemically safe in cats at appropriate doses. That is an important difference from aciclovir and valaciclovir, human antivirals with documented toxicity in cats. Never substitute a human antiviral for HerpX™.
Dosing based on published feline studies
Famciclovir use in cats is supported by pharmacokinetic studies, dose-optimisation modelling and a clinical series of 59 cases covering ocular, respiratory and cutaneous lesions. Those data underpin the widely used guidance of approximately 90 mg/kg every 12 hours.
Before you start
Not every case of conjunctivitis in cats is caused by feline herpesvirus. Chlamydial and mycoplasmal conjunctivitis need different treatment. Consult your veterinarian before starting.
Technical sheet
Active ingredient
Famciclovir 180 mg per tablet
Excipients
Magnesium stearate 2 mg Croscarmellose sodium 16 mg Hypromellose (HPMC) 24 mg Colloidal silicon dioxide 2 mg Other excipients 175 mg
Presentation
180 mg tablets, 60 tablets per pack
Indication
Antiviral treatment of feline herpesvirus (FHV-1), including ocular and upper respiratory flare-ups.
Dosage
180 mg (1 tablet) per 2 kg body weight, every 12 hours, or as directed by your veterinarian. Give 1 hour before feeding to aid absorption.
Duration
Continue until your veterinarian advises otherwise, even once signs have resolved. Do not reduce the dose or stop without veterinary direction.
Regulatory status
This product is not licensed for use in cats. It is intended for off-label veterinary use under professional supervision and requires informed owner consent.
Storage
Store at room temperature (15 to 25 °C), protected from moisture and direct sunlight. Keep out of reach of children.
Packaging
Cold-form aluminium-aluminium blister Carton 52 x 110 x 30 mm, net weight 25 g
Shelf life
12 months from the manufacturing date shown on the pack.
For veterinary use only.
Dosage and administration
Famciclovir is dosed by body weight. The guidance supported by the published feline studies is approximately 90 mg/kg every 12 hours.
The actual dose depends on your cat's weight and your veterinarian's assessment. Always confirm how many HerpX™ 180 mg tablets make up each dose.
Reference (confirm with your veterinarian)
Around 2 kg: 180 mg (1 tablet) every 12 hours
Around 4 kg: 360 mg (2 tablets) every 12 hours
Around 6 kg: 540 mg (3 tablets) every 12 hours
Give 1 hour before feeding to aid absorption.
Do not reduce the dose
Cats convert famciclovir to penciclovir less efficiently than people do, so the required dose is far higher than the human reference. The most common error is under-dosing by reasoning down from a human dose. Even as signs improve, do not reduce or stop without veterinary direction.
Follow-up
Keep regular check-ups through treatment to assess response and decide on continuation or adjustment.
Flare-ups and long-term management
Can signs return after treatment?
They can. Famciclovir acts on active virus but does not clear the latent virus in nerve tissue. Flare-ups are triggered by stress, other illness or immunosuppression. They are normal herpesvirus behaviour and do not indicate treatment failure.
Does famciclovir prevent flare-ups?
It does not prevent them, but it reduces the severity and duration of each episode. Repeat treatment is often effective in recurrent cases. Reducing stress and maintaining good nutrition also helps lower the frequency.
When to treat again
If sneezing, ocular discharge or lethargy return, speak to your veterinarian. Starting famciclovir early shortens recovery time.
سياسة الإرجاع والاسترداد
To uphold the highest standards of pharmaceutical safety, quality, and product integrity, we are unable to accept returns or issue refunds once an order has been delivered. This ensures that every product that reaches our customers has been handled, stored, and managed according to strict quality control requirements.
If your order is damaged, defective, or lost in transit, we will provide a free replacement at no additional cost to you. Simply contact our support team with your order details, and we will resolve the issue promptly.
This policy protects the safety of all customers and ensures that every product dispensed remains uncompromised and fully compliant with pharmaceutical standards.
Composition
Active ingredient: famciclovir 180 mg
Excipients: magnesium stearate 2 mg, croscarmellose sodium 16 mg, hypromellose 24 mg, colloidal silicon dioxide 2 mg, other excipients 175 mg