Aciclovir(Topical): Uses, Dosage, Side Effects

Generic Name

Aciclovir

Therapeutic Class: Herpes simplex & Varicella-zoster virus infections

Indications:

Aciclovir is indicated for-

• The treatment of viral infections thanks to herpes simplex virus (type I & II) and varicella-zoster virus (herpes zoster & chickenpox).
• The treatment of herpes simplex virus infections of the skin and mucous membranes including initial and recurrent herpes genitalis.
• The prophylaxis of herpes simplex infections in immunocompromised patients.

Description:

Aciclovir may be a synthetic purine derivative. Aciclovir exerts its antiviral effect on the herpes simplex virus (HSV) and varicella-zoster virus by interfering with DNA synthesis and inhibiting viral replication. In cells infected with herpes, 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 then via other cellular enzymes to the triphosphate which is that the pharmacologically active sort of the drug. 15-30% of an oral dose of the drug is absorbed from the alimentary canal. Peak plasma concentrations usually occur within 1.5-2 hours after oral administration. it's cosmopolitan into body tissues and fluids including the brain, saliva, lung, 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.

Dosage & Administration:

Treatment of initial herpes simplex:

• Adult: 200 mg 5 times daily usually for five days. For immunocompromised patients 400 mg 5 times daily for five days or as directed by the registered physician.
• Children under 2 years: half the adult's dose.
• Children over 2 years: Adult dose.

Prophylactic treatment of herpes simplex within the immunocompromised:

• Adult: 200 to 400 mg 4 times daily.
• Children under 2 years: half the adult dose.
• Children over 2 years: Adult dose.

Treatment of varicella (chickenpox):

• Adult and youngsters over 40 kg: 800 mg 4 times daily for five days.
• Children 2 years aged and older (below 40 kg): 20 mg/kg per dose orally 4 times daily (80 mg/kg/day) for five days.

Treatment of herpes zoster (Shingles): 800 mg 5 times daily for 7 days.

For the treatment of initial rectal (Proctitis) herpes infections: 400 mg 5 times daily for 10 days or until clinical resolution occurs has been recommended.

Treatment of herpes simplex and prevention of recurrence: 200 mg 4 times daily or 400 mg twice daily possibly reduced to 200 mg 2 or 3 times daily and interrupted every 6-12 months.

Interaction:

Concomitant administration of probenecid and acyclovir has reportedly increased the mean plasma half-life and decreased urinary excretion and renal clearance of acyclovir. Amphotericin B has been shown to potentiate the antiviral effect of acyclovir against the pseudorabies virus in vitro when both drugs are added to the medium. Ketoconazole and acyclovir have shown dose-dependent, synergistic, antiviral activity against herpes simplex virus types 1 and a couple of (HSV-1 and HSV-2) in in-vitro replication studies.

Contraindications:

Aciclovir tablet is contraindicated in patients known to be hypersensitive to Aciclovir.

Side Effects:

Rashes, gastro-intestinal disturbances, rise in bilirubin and liver-related enzymes, increases in blood urea and creatinine, decreases in hematological indices, headache, neurological reactions, fatigue.

Pregnancy & Lactation:

Pregnancy category B. there's no adequate and well-controlled studies in pregnant women. Aciclovir shouldn't be used during pregnancy unless the potential benefit justifies the potential risk to the fetus. Caution should be exercised when it's administered to a nursing mother.

Precautions & Warnings:

Aciclovir should be administered with caution to patients with renal impairment and doses should be adjusted consistent with creatinine clearance.

Storage:

Acyclovir should be stored below 25°C. Protect from light and moisture. Keep drugs out of the reach of youngsters.