Group: antiviral agent
Tablet, 200 mg [EDL], 400 mg, 800 mg
Suspension, 200 mg/5 ml
Powder for injection 250 mg [EDL], 500 mg

General information

Aciclovir, which is derived from guanine, is a synthetic purine nucleoside analogue with antiviral properties. It acts against herpes viruses by disrupting DNA synthesis and thus inhibiting viral replication. However, in immunocompromised patients, alpha herpes viruses are sometimes resistant to aciclovir.

Absorption from the gastrointestinal tract is variable and incomplete. Aciclovir is widely distributed in tissues and body fluids and is excreted in the urine primarily unchanged.

Clinical information

Uses

• severe primary genital herpes
• herpes viral encephalitis
• disseminated zoster.

Dosage and administration

Intravenous infusions should be administered slowly over a period of at least one hour to reduce the risk of acute impairment of renal function.

Primary genital herpes

5 mg/kg intravenously three times daily for 5 days.
200 mg - 400 mg orally five times a day for 5-7 days.

Occasionally, higher doses i.e. 800 mg orally five times a day may be required.

In patients that relapse frequently (i.e. more than 6 times/year) maintenance therapy may be required. The most commonly used dose is aciclovir 400 mg twice a day.

Herpes viral encephalitis

10 mg/kg intravenously three times daily for 10 days

Disseminated zoster

10 mg/kg intravenously three times daily for 7 days

Contraindications

Known hypersensitivity to purine nucleoside analogues.

Precautions

Reduce the dose in renal impairment

Use in pregnancy

Aciclovir is mutagenic in animal models. Its use in pregnancy must be determined by the physical state of the mother.

Adverse effects

Headache, nausea and vomiting occur commonly after oral administration. Transient renal impairment may occur during intravenous therapy, possibly as a result of crystallisation in the renal tubules. This usually responds rapidly to dosage reduction or withdrawal of the drug. Acute renal failure has responded to haemodialysis.

Overdosage

Since aciclovir is incompletely absorbed from the gastrointestinal tract, oral overdosage is unlikely to have serious sequelae. Blood concentrations can be lowered by haemodialysis.

Storage

Tablets should be stored in tightly closed containers below 25°C.

Suspension and powder for injection should be stored below 25°C.