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Other brands with the same active ingredient

These brands contain the same active ingredient (Acyclovir). Same strength and form. Confirm the switch with your doctor or pharmacist.

Indications & Uses

Acerux 400 is indicated for:

Pharmacology

Acyclovir is an antiviral medicine that is highly active in laboratory studies against Herpes simplex virus (HSV) types I and II and Varicella zoster virus, while remaining low in toxicity to mammalian cells. After entering a herpes-infected cell, acyclovir is phosphorylated into the active compound acyclovir triphosphate. The first step of this process depends on the presence of the viral-coded thymidine kinase. Acyclovir triphosphate then acts as both an inhibitor of and a substrate for the herpes-specified DNA polymerase, blocking further viral DNA synthesis without disrupting normal cellular processes.

Dosage Reference

Reference Information Only

Dosages shown are general references from official sources. Always consult your doctor or pharmacist for personalized dosing.

Adults:

The dose is the same for every age group. Apply a 10 mm strip of ointment inside the lower eyelid (lower conjunctival sac) five times a day, at roughly four-hour intervals. Keep using it for at least 3 days after the eye has healed.

Side Effects

Very common: superficial punctate keratopathy. This did not require stopping treatment early and healed without any apparent lasting effects. Common: transient mild stinging of the eye immediately after application; conjunctivitis. Rare: blepharitis.

Cautions & Contraindications

Warnings & Precautions

Do not exceed the recommended dose, how often the medicine is applied, or how long the treatment lasts.

Contraindications

Acyclovir should not be used by anyone with a known allergy (hypersensitivity) to acyclovir or valacyclovir.

Pregnancy & Breastfeeding

Pregnancy category B. No adequate, well-controlled studies have looked at Acyclovir's effects in pregnant women. It is also not known whether the topical form of this medicine passes into breast milk.

⚠️ Talk to your doctor before taking any medicine during pregnancy or while breastfeeding.

Use in Special Populations

Pediatric use: For children aged 1 to 12 years, the dose of Acyclovir IV injection should be worked out from body surface area. Children in this age group with Herpes simplex infections (except Herpes simplex encephalitis) or Varicella zoster infections should get Acyclovir IV Infusion at 250 mg/m2 (equivalent to 5 mg/kg in adults). Immunocompromised children of the same age with Varicella zoster virus infection, or with Herpes simplex encephalitis, should get Acyclovir IV Infusion at 500 mg/m2 (equivalent to 10 mg/kg in adults). If a child has impaired renal function, the dose needs to be changed to suit the degree of impairment.

Geriatric use: No data are available on this age group. But creatinine clearance is often low in the elderly, so special attention should be given to reducing the dose.

In patients with renal impairment: Acyclovir should be given with caution because the drug is excreted through the kidneys. These dose changes are suggested:

CrCl 25 to 50 ml/min: 5 or 10 mg/kg every 12 hours.

CrCl 10 to 25 ml/min: 5 or 10 mg/kg every 24 hours.

CrCl 0 to 10 ml/min: 2.5 or 5 mg/kg every 24 hours and after dialysis.

Overdose

Too much intravenous Acyclovir has led to a rise in serum creatinine and blood urea nitrogen, and after that to renal failure. Neurological effects have also been reported with overdose, including confusion, hallucinations, agitation, seizures and coma. Patients need adequate hydration, because it lowers the chance of crystals forming in the urine. Hemodialysis removes Acyclovir from the blood to a significant degree, so it may be considered as an option when managing an Acyclovir overdose.

⚠️ In an emergency call 999 or go to the nearest hospital emergency department.

Storage

Keep Acyclovir in a cool, dry place, away from light, and out of reach of children. Don't touch the tip of the tube, because this may contaminate the product. Once the tube has been open for one month, don't use the medicine in it any more.

Drug Interactions

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Common questions about Acerux 400 400 mg

What is Acerux 400 400 mg Tablet?

Acerux 400 400 mg Tablet is a medicine that contains Acyclovir. It is made by Opsonin Pharma Limited. It belongs to the Herpes simplex & Varicella-zoster virus infections group of medicines.

What is Acerux 400 used for?

Acerux 400 is used for: Viral Infection.

What are the side effects of Acerux 400?

Very common: superficial punctate keratopathy. This did not require stopping treatment early and healed without any apparent lasting effects.

Can I take Acerux 400 during pregnancy or while breastfeeding?

Pregnancy category B. No adequate, well-controlled studies have looked at Acyclovir's effects in pregnant women. Talk to your doctor before taking any medicine during pregnancy or while breastfeeding.

What happens if I take too much Acerux 400?

Too much intravenous Acyclovir has led to a rise in serum creatinine and blood urea nitrogen, and after that to renal failure. Neurological effects have also been reported with overdose, including confusion, hallucinations, agitation, seizures and coma. In an emergency call 999 or go to the nearest hospital emergency department.

How should I store Acerux 400?

Keep Acyclovir in a cool, dry place, away from light, and out of reach of children. Don't touch the tip of the tube, because this may contaminate the product.

Can I take other medicines with Acerux 400?

Some medicines can interact with Acyclovir, for example: Tenofovir Alafenamide, Phenytoin Sodium, Mycophenolate Mofetil, Lamivudine + Zidovudine + Nevirapine, Mycophenolic acid. Tell your doctor or pharmacist about every medicine you take.

Do I need a prescription for Acerux 400?

Acerux 400 is a prescription (Rx) medicine. Take it as your doctor advises.

Last updated: 15 Aug 2026