Xovir

Aciclovir is indicated for-

• The treatment of viral infections due to Herpes simplex virus (type I & II) and Varicella zoster virus (herpes zoster & chicken pox).
• The treatment of Herpes simplex virus infections of the skin and mucous membranes including initial and recurrent genital herpes and herpes labialis.
• The prophylaxis of Herpes simplex infections in immunocompromised patients

Aciclovir is a synthetic purine derivative. Aciclovir exerts its antiviral effect on Herpes simplex virus (HSV) and Varicella-zoster virus by interfering with DNA synthesis and inhibiting viral replication. In cells infected with herpes virus, the antiviral activity of Aciclovir appears to depend principally on the intracellular conversion of the drug to Aciclovir Triphosphate. Aciclovir is converted to Aciclovir Monophosphate principally via virus coded thymidine kinase; the monophosphate is phosphorylated to the diphosphate via cellular guanylate kinase and then via another cellular enzyme to the triphosphate, which is the pharmacologically active form of the drug. 15-30% of an oral dose of the drug is absorbed from Gl tract. Peak plasma concentrations usually occur within 1.5-2 hours after oral administration. It is widely distributed into body tissues and fluids including the brain, saliva, lungs, liver, muscle, spleen, uterus, vaginal mucosa and secretions, CSF, and herpetic vesicular fluid. Aciclovir is excreted through the kidney by the glomerular filtration & tubular secretion.

Probenecid reduces Aciclovir excretion and so increases plasma concentration and risk of toxicity.

Rash, gastrointestinal disturbance, rise in bilirubin and liver-related enzymes, increase in blood urea and creatinine, decrease in hematological indices, headache, neurological reaction, fatigue.

Pregnancy category B. Aciclovir should not be used during pregnancy unless the potential benefit justifies the potential risk to the fetus. Caution should be exercised when it is administered to a nursing mother.

Aciclovir should be administered with caution in patients with renal impairment and doses should be adjusted according to creatinine clearance. Monitor neutrophil count at least twice weekly in neonates.

Herpes simplex & Varicella-zoster virus infections

Should be stored below 25°C. It should be protected from light and moisture.Keep out of the reach of children.