Prescription requiredAntiviral

Zovirax 400 — Side Effects & Warnings

Known side effects of Zovirax 400 include Nausea, vomiting, diarrhoea, abdominal pain, headache, dizziness, rash, fatigue. Not everyone experiences these side effects.

Medically reviewed by Dr. Balaji Krishnan, MBBS · Updated August 2026

Common Side Effects

Nausea
vomiting
diarrhoea
abdominal pain
headache
dizziness
rash
fatigue

This is not an exhaustive list. Consult your doctor if you notice any unusual symptoms.

Important Warnings

Use with caution in kidney disease/elderly—dose adjustment may be needed and risk of kidney toxicity increases with dehydration. Ensure adequate fluid intake. Stop and seek medical help if severe allergic reaction, unusual bruising/bleeding, confusion, tremors, or severe skin rash occurs. Not a cure for herpes and may not fully prevent transmission—follow safe sexual practices. Use only on medical advice in immunocompromised patients.

Drug Interactions

Zovirax 400 may interact with the following:

Probenecid
cimetidine
mycophenolate mofetil
other nephrotoxic drugs (e.g.
aminoglycosides
amphotericin B
cyclosporine
tacrolimus
high-dose NSAIDs)

Always tell your doctor about all medicines you are taking, including over-the-counter drugs and supplements.

Pregnancy Safety

Consult doctor (generally considered usable when benefits outweigh risks)

Alcohol Interaction

Use with caution (no known direct interaction; alcohol may worsen dehydration and symptoms)

Habit Forming

Storage

Store below 25°C in a cool, dry place. Protect from moisture and direct light. Keep out of reach of children.

Zovirax 400 — Safety Summary

Composition: Acyclovir 400 mg (as tablets)
Prescription: Required (Rx)
Pregnancy: Consult doctor (generally considered usable when benefits outweigh risks)
Alcohol: Use with caution (no known direct interaction; alcohol may worsen dehydration and symptoms)
Habit forming: No

Zovirax 400 — Safety FAQs

What should I do if I experience side effects?

Mild side effects often resolve on their own. If side effects are severe or persistent, stop the medicine and consult your doctor immediately.

Are all listed side effects common?

No. Some side effects are common while others are rare. Not everyone experiences side effects. Consult your doctor if you are concerned.

Can I take this medicine with other drugs?

Some medicines interact with each other. Always inform your doctor about all medicines you are currently taking.

When should I seek emergency help?

Seek immediate medical attention if you experience severe allergic reactions (difficulty breathing, swelling of face/throat), chest pain, or any life-threatening symptoms.

Get help from a doctor

Consult a doctor

Discuss side effects with a qualified doctor online.

View all medicines

Full product details for Zovirax 400.

Lab tests

Book tests to monitor your health while on medication.

Sick leave certificate

Unwell and need rest? A doctor can issue a leave certificate online, from ₹499.

Safety disclaimer

This information is for educational purposes only and is not a substitute for professional medical advice. If you experience severe side effects, seek medical attention immediately.