Famvir Side Effects in Pakistan

A complete guide to the side effects of Famvir. From common effects to serious warnings — everything you need to know is on this page.

Compiled by the PakVita Editorial Team · AI-assisted drafting with editorial review · Sourced from DRAP, WHO, BNF · Last updated: 2026-07-09

Side Effects

Quick Answer

Common side effects of Famvir include headache, nausea, and diarrhoea. Serious effects such as severe allergic reaction or liver enzyme elevation require immediate medical attention. Most patients tolerate Famvir well at the correct dose. Contact your doctor if any side effect persists or worsens.

Side Effects at a Glance

Common

Headache
Nausea
Diarrhoea

Serious — See a Doctor

Severe allergic reaction (anaphylaxis)
Liver enzyme elevation
Acute kidney injury (rare)

When to See a Doctor Immediately

Signs of allergic reaction — rash, swelling of face or throat, difficulty breathing
Yellowing of skin or eyes (possible liver effect)
Reduced urination or swelling of ankles

Famvir Side Effects (Nuksanat)

Famvir (famciclovir) is generally safe when taken at the correct dose. However, like all medicines, it can cause side effects in some patients.

Common Side Effects (Aam Nuksanat)

Headache
Nausea
Diarrhoea

These side effects are usually mild. If they continue, inform your doctor.

Serious Side Effects (Sanjeedah Nuksanat)

Severe allergic reaction (anaphylaxis) — see a doctor immediately
Liver enzyme elevation — see a doctor immediately
Acute kidney injury (rare) — see a doctor immediately

When to See a Doctor (Kab Doctor Se Milna Zaroori Hai)

Signs of allergic reaction — rash, swelling of face or throat, difficulty breathing
Yellowing of skin or eyes (possible liver effect)
Reduced urination or swelling of ankles

Warnings and Precautions (Ihtiyat)

Do not use Famvir if you are allergic to famciclovir or penciclovir
Dose adjustment required in patients with reduced kidney function

Side Effects Summary Table

Type	Side Effect	Action
Common	Headache	Monitor / inform doctor
Common	Nausea	Monitor / inform doctor
Common	Diarrhoea	Monitor / inform doctor
Serious	Severe allergic reaction	See a doctor immediately
Serious	Liver enzyme elevation	See a doctor immediately

Reporting Side Effects

If you notice any unexpected side effect, report it on the DRAP pharmacovigilance portal: https://www.dra.gov.pk/pharmacovigilance

The information in this guide is for educational purposes only. If you notice any side effect, contact your doctor or pharmacist.

Frequently Asked Questions

What are the most common side effects of Famvir?

The most commonly reported side effects of Famvir include headache and nausea. These are usually mild and go away on their own. Inform your doctor if they persist.

Can Famvir cause allergic reactions?

Yes, like all medicines, Famvir can cause allergic reactions in some people. Signs include rash, itching, swelling, or difficulty breathing. Stop use and seek medical help immediately if this happens.

Is Famvir safe to take for a long time?

Long-term use of Famvir for herpes suppression is generally well-tolerated. Your doctor will monitor for any signs of liver enzyme elevation or kidney effects if continued use is needed.

What should I do if I experience side effects from Famvir?

For mild side effects, inform your pharmacist. For serious effects such as allergic reaction or jaundice, stop the medicine and contact your doctor immediately or go to the nearest hospital.

Does Famvir affect the liver or kidneys?

Famvir may require dose adjustment in patients with liver or kidney impairment. Your doctor will advise based on your test results and overall health condition.

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Sources

DRAP Registered Products Database — Drug Regulatory Authority of Pakistan
WHO Model List of Essential Medicines, 23rd ed. (2023) — World Health Organization
British National Formulary (BNF) — BMJ Group & Pharmaceutical Press

Medical disclaimer

This page is for educational use only and does not replace professional medical advice. Always confirm diagnosis, dose, and interactions with a qualified doctor or pharmacist before starting or changing any medicine.