Famvir® (Famciclovir) Tablets for Cats

Famciclovir is an oral antiviral used by veterinarians to manage feline herpesvirus infections that affect the eyes and upper airways. Canadian pricing helps lower your cost, and the medicine ships to the US from Canada. This page explains uses, dosing basics, storage, safety, and how to order.

At CanadianInsulin, orders are filled by licensed Canadian pharmacies after we confirm a valid prescription with your clinic.

What Famvir® Is and How It Works

Famvir® is the original brand name for famciclovir, a prodrug that converts to penciclovir in the body. Penciclovir blocks viral DNA polymerase, which slows replication of herpesviruses. In cats, veterinarians prescribe famciclovir off-label for feline herpesvirus type 1 (FHV-1) to reduce ocular inflammation, sneezing, nasal discharge, and discomfort. If you pay cash, you may still find value from Canadian pricing even without insurance.

We coordinate US delivery from Canada so you can complete your order online and have your clinic verify the prescription. Your veterinarian determines the plan based on your cat’s age, weight, kidney function, and clinical signs.

Who Famvir Is For

Veterinarians use famciclovir for cats with confirmed or strongly suspected FHV-1 disease, including conjunctivitis, keratitis, corneal ulcers, and upper respiratory flare-ups. It may be considered for cats with recurrent herpes outbreaks, shelter-acquired infections, or stress-triggered relapses.

It is not right for every cat. Cats with significant kidney disease, dehydration, or known hypersensitivity to famciclovir or penciclovir may not be candidates. Always discuss pregnancy or nursing status with your veterinarian before use. Human patients should not take pet-directed prescriptions; follow your own clinician’s guidance.

Dosage and Usage

Because famciclovir for cats is extra-label, your veterinarian will set the dose and schedule. Typical use involves oral tablets given two or three times daily at first, followed by a step-down to the lowest effective frequency as symptoms improve. For acute flares, treatment often continues for several days after signs resolve. For chronic or recurrent disease, your veterinarian may prescribe longer courses with periodic reassessment.

Give doses at the same times each day to support consistent antiviral levels. Administer with a small meal or treat if your cat has a sensitive stomach. Do not change the dose or stop early unless your veterinarian advises.

Strengths and Forms

Famciclovir is supplied as oral tablets in commonly published strengths:

• 125 mg tablets
• 250 mg tablets
• 500 mg tablets

Availability can vary by pharmacy and manufacturer. Your veterinarian will select a strength that suits your cat’s plan. Some cats may need compounded options if very small doses are prescribed; your clinic can advise.

Missed Dose and Timing

If you miss a dose, give it when you remember unless it is close to the next scheduled time. If it is near the next dose, skip the missed dose and resume the regular schedule. Do not double up. Consistent timing helps control viral replication and may shorten outbreaks.

Storage and Travel Basics

Store tablets at room temperature in a dry place, away from heat and humidity. Keep them in the original container with the label intact, out of reach of children and pets. When traveling, carry the medicine in your hand luggage with a copy of your cat’s prescription. Avoid excess heat. Ask your veterinarian for travel documentation if you expect border checks.

Benefits

• Targets herpesvirus replication, helping reduce ocular and respiratory symptoms
• Oral tablet form for home use under veterinary guidance
• Can be used during acute flares or to manage recurrent episodes
• Often well tolerated when dosed appropriately
• Canadian pricing with US delivery can reduce your out-of-pocket cost

Side Effects and Safety

• Decreased appetite
• Vomiting or soft stools
• Lethargy or mild behavioral changes
• Increased thirst or urination, especially if kidney status is a concern
• Headache or dizziness have been reported in people; pets may appear subdued

Serious reactions are uncommon but can include allergic responses such as facial swelling, hives, or breathing difficulty, and signs of kidney strain in susceptible cats. Stop the medication and contact your veterinarian urgently if severe vomiting, profound lethargy, jaundice, or collapse occurs.

Drug Interactions and Cautions

Tell your veterinarian about all medicines, supplements, and recent injections. Dose adjustments may be needed if your cat has kidney impairment. Caution is advised with other drugs that stress the kidneys. Agents that affect renal excretion, such as probenecid or cimetidine in humans, can alter famciclovir levels; your vet will evaluate relevance for pets. Avoid giving new over-the-counter remedies without veterinary approval. For additional pet-care context on antibiotics sometimes used for secondary infections, see our guide Explore Doxycycline For Dogs And.

What to Expect Over Time

Many cats begin to show comfort improvements as the antiviral takes effect, with less squinting, eye discharge, sneezing, and nasal congestion during an active flare. Ocular lesions usually require close follow-up to ensure healing. Recurrences can still happen because herpesviruses persist in the body, but outbreaks may be milder or shorter with timely treatment. Your veterinarian may combine famciclovir with supportive care such as eye lubricants or nutrition support. Some caregivers also consider lysine supplementation; options like Nutri Lys Lysine Supplement Gel or Nurti Lys Lysine Supplement can be discussed with your clinic.

Compare With Alternatives

Topical and oral antivirals are potential options. Your veterinarian might consider oral Acyclovir in certain cases, though efficacy and tolerability differ by species and product. For localized lesions, a topical such as Zovirax® Oint 5 may be part of a broader plan when appropriate. Your clinic will tailor therapy to the site and severity of disease.

Pricing and Access

Compare famciclovir cost and Canadian pricing before you order. You can buy famciclovir online through our referral service and have US shipping from Canada after prescription verification. Check current price options and generics to see typical cash-pay savings. If you prefer, you can also browse related Pet Medications.

For budget planning, review your cat’s projected course length with your veterinarian. Multi-month fills may lower your overall cost, and refill reminders help you avoid gaps. Many customers save even without insurance by selecting generic famciclovir tablets.

Encrypted checkout protects your information during payment.

Availability and Substitutions

Famciclovir tablets are widely available in multiple strengths. If a specific strength is temporarily unavailable, your veterinarian may recommend a different strength or an alternative approach, such as topical therapy or supportive care. Preventive vaccination can also reduce disease impact over a lifetime; talk to your vet about Nobivac® Feline 3 Hcp for core protection that includes herpesvirus.

Patient Suitability and Cost Saving Tips

Good candidates include cats with confirmed FHV-1 and recurrent ocular or respiratory signs who tolerate oral medication. Use with caution in cats with kidney disease, the very young or very old, and those with poor appetite. Your veterinarian may add eye drops or lubricants if corneal disease is present.

• Ask about the simplest schedule your cat can tolerate
• Confirm tablet strength to avoid complex splitting
• Use automatic reminders for timed dosing
• Combine with stress reduction and environmental support
• Discuss generic options to reduce cost

Questions to Ask Your Clinician

• Is famciclovir appropriate for my cat’s FHV-1 signs?
• What strength and schedule should we start with?
• How long should we treat this flare, and when should we reassess?
• Which side effects require a call or urgent visit?
• Do we need eye drops alongside oral therapy?
• How should we adapt the plan if kidney values change?
• Are lysine supplements or stress-management steps appropriate?

Authoritative Sources

FDA DailyMed: Famciclovir Tablets

Health Canada DPD: Famciclovir

FDA: Extra-Label Use in Animals

Ready to start? Complete your request for US delivery from Canada, and we will confirm your prescription with your clinic.

Disclaimer: This information is educational and does not replace veterinary advice. Use only as directed by your veterinarian.