Acyclovir

It is a deoxiguanosine analogue and requires a virus specific enzyme for conversion to the active metabolite that inhibits DNA synthesis and viral replication.

Indications

Genital herpes simplex, Mucocutaneous H. Simplex, H. Simplex encephalitis, H, simplex keratitis, Herpes zoster, chicken, pox.

Dosage

Adults: Herpes simplex: 200mg 5 times daily at 4 hrs interval for 5 days. Herpes zoster: 800 mg 5 times daily at 4 hrs interval for 7 days. Prophylaxis or suppression: 200 mg 4 times daily Children: below: 2 yrs; Herpes simplex: 100mg 5 times at 4 hrs interval children above 2 yrs dose some as adult. Prophylaxis for children below 2 yrs: 100 mg 4 times daily at 6 hrs intervals and over 2 yrs: same as adult.

Contra-Indications

Hypersensitivity. glaucoma, psychiatic diseases, depression.

Special Precautions

Renal impairment necessitates dose reduction. Maintain adequate hydration. Paediatrics: reduced dose necessary. Not recommended in age below 2 years. Pregnancy: Contraindicated orally and parenterally. Lactation: May reduce lactation.

Side Effects

Orally causes headache, nausea, CNS effects, intravenously causes sweating, emesis and fall in B.P, dose dependent decrease in G.F.R, reversible neurological manifestations.

Drug Interactions

Probenecid increases and prolongs the plasma level.