Aciclovir is indicated for:
Aciclovir is a synthetic purine derivative that works as an antiviral against Herpes simplex virus (HSV) and Varicella-zoster virus by interfering with viral DNA synthesis and inhibiting replication. In virus-infected cells, Aciclovir’s antiviral effect mainly depends on its intracellular conversion to Aciclovir Triphosphate.
Aciclovir is first converted to Aciclovir Monophosphate primarily by virus-encoded thymidine kinase. The monophosphate is then phosphorylated to the diphosphate by cellular guanylate kinase and finally converted to the triphosphate form by another cellular enzyme, which is the pharmacologically active form of the drug.
Approximately 15-30% of an oral dose is absorbed from the gastrointestinal tract, with peak plasma concentrations occurring 1.5 to 2 hours after administration. Aciclovir is widely distributed into body tissues and fluids including the brain, saliva, lungs, liver, muscle, spleen, uterus, vaginal mucosa and secretions, cerebrospinal fluid (CSF), and herpetic vesicular fluid. The drug is primarily excreted through the kidneys via glomerular filtration and tubular secretion.
Treatment of initial herpes simplex: 200 mg 5 times daily usually for 5 days.
For immunocompromised patients:
• Adult: 400 mg 5 times daily for 5 days (longer if new lesions appear during treatment or if healing is incomplete; increase dose to 800 mg 5 times daily for genital herpes in immunocompromised) or as directed by the registered physician.
• Children under 2 years: Half of the adult dose.
• Children over 2 years: Adult dose.
Prevention of recurrence of herpes simplex:
• Adult: 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.
• Children under 2 years: Half of the adult dose.
• Children over 2 years: Adult dose.
Prophylactic treatment of herpes simplex in the immunocompromised patients:
• Adult: 200 to 400 mg 4 times daily.
• Children under 2 years: Half of the adult dose.
• Children over 2 years: Adult dose.
Treatment of vericella (chicken pox):
• Adult and children over 40 kg: 800 mg 4 times daily for 5 days.
• Children below 40 kg: 20 mg/kg (maximum 800 mg) per dose orally 4 times daily (80 mg/kg/day) for 5 days.
• Children 1 month-2 years: 200 mg 4 times daily for 5 days.
• Children 2-5 years:400 mg 4 times daily for 5 days.
• Children 6-12 years:800 mg 4 times daily for 5 days.
Treatment of herpes zoster (Shingles): 800 mg 5 times daily for 7 days.
Treatment of initial rectal (Proctitis) herpes infections: An oral Aciclovir dosage of 400 mg 5 times daily for 10 days or until clinical resolution occurs has been recommended.
Renal Impairment: For patients with severe renal impairment, a reduction of the doses is recommended.
Probenecid reduces the excretion of Aciclovir, which increases its plasma concentration and the risk of toxicity.
Aciclovir should not be used in patients who are known to have hypersensitivity to Aciclovir.
Common side effects of Aciclovir include rash, gastrointestinal disturbances, elevated bilirubin and liver enzymes, increased blood urea and creatinine, changes in blood counts, headache, neurological reactions, and fatigue.
Aciclovir is classified as Pregnancy Category B. It should only be used during pregnancy if the potential benefits outweigh the potential risks to the fetus. Caution is advised when administering Aciclovir to a breastfeeding mother.
Aciclovir should be used with caution in patients with kidney (renal) impairment, and the dose must be adjusted according to creatinine clearance. In newborns, neutrophil counts should be monitored at least twice a week.
Herpes simplex & Varicella-zoster virus infections.
Aciclovir should be stored at a temperature below 25°C, protected from light and moisture. Keep it out of the reach of children.
What is Aciclovir used for?
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No available drugs found