Description, Composition, Actions and pharmacology, Indications, Contraindications, Precautions, Main side/adverse effects, Drug interaction, Treatment of overdosage, Dosage and administration, Storage, Presentation/packing and Manufacturer of Virest Tablet Medicine for Viral Infection, Chickenpox.
Virest 200 Tablet: Hexagon-shaped, blue uncoated tablet, bevel-edged with flat faces.
Virest 400 Tablet: Hexagon-shaped, pink uncoated tablet, bevel-edged with flat faces.
Virest 200 Table: Aciclovir 200 mg/tablet
Virest 400 Table: Aciclovir 400 mg/tablet
Actions and Pharmacology
Aciclovir is converted to aciclovir monophosphate, a nucleotide, by the viral thymidine kinases of herpes simplex virus (HSV) and varicella-zoster virus (VZV). Aciclovir monophosphate is converted to the diphosphate by cellular guanylate kinase and to the triphosphate by a number of cellular enzymes. Aciclovir triphosphate interferes with HSV and VZV DNA polymerase and inhibits viral DNA replication. The triphosphate can be incorporated into growing chains of DNA by viral DNA polymerase, resulting in termination of the DNA chain. Aciclovir is therefore selectively converted to the active triphosphate form by HSV and VZV-infected cells. Aciclovir crosses the placenta and are excreted through the kidney and in breast milk. The terminal half-life is reported to be 2-3 hours for adults without renal impairment. The half-life increases in patients with renal impairment.
Aciclovir is poorly absorbed from the gastrointestinal tract. Not significantly affected by food.
Aciclovir is used for the treatment of viral infections due to herpes simplex virus (type 1 & 2) and varicella-zoster virus (zoster & chickenpox).
This medication should not be used when the following medical problems exist:
• Hypersensitivity to aciclovir or ganciclovir.
• Dehydration or renal function impairment – intravenous aciclovir may increase the potential for nephrotoxicity; it is recommended
that aciclovir be administered in a reduced dosage to patients with impaired renal function
• Neurological abnormalities or prior neurotogic reactions to cytotoxic medications – intravenous aciclovir may increase the potential
for neurologic side effects.
• Aciclovir should be used with caution to Patients with renal impairment and doses should be adjusted according to creatinine clearance.
• Women with herpes genitalis may have an increased risk of developing cervical cancer; annual Pap tests may be required. Checking with physician if no improvement within a few days
• Use of aciclovir has not been shown to prevent the transmission of herpes simplex virus to sexual partners
• Aciclovir crosses placenta. No adverse fetal effects have been reported. FDA Pregnancy category C
• Aciclovir passes into breast milk. No toxicity was observed infants
Main Side/Adverse Effects
• Acute renal failure – Gastrointestinal disturbances (nausea or vomiting, diarrhea, abdominal pain)
• Headache – Increase in blood concentrations of urea and creatinine
• Lightheadedness – Increase values for liver enzymes
• Skin rashes – Encephalopathic changes (lethargy, confusion, tremors, seizures)
• Haematological changes
Probenecid reduces excretion of aciclovir when used concurrently, resulting in increased aciclovir plasma concentration and risk of toxicity.
Treatment of overdosage
Since there is no specific antidote, treatment of adverse effects and/or overdose should be symptomatic and supportive with possible
utilization of the following:
• Adequate hydration to prevent precipitation of aciclovir in the renal tubules
• Hemodialysis to aid in the removal of aciclovir from the blood, especially in patients with acute renal failure and anuria
Dosage and Administration
Genital herpes Infection
Initial therapy: Oral, 200 mg 5 times a day for 10 days.
• Creatinine clearance >10ml/min: Oral, 200mg 5times a day for 10 days.
• Creatinine clearance 0 – 10ml/min: Oral, 200 mg twice a day for 10 days.
Intermittent therapy: Oral, 200 mg 5 times a day for 5 days.
• Creatinine clearance >10 ml/min: Oral, 200 mg 5 times a day for 5 days.
• Creatinine clearance 0-10 ml/min: Oral, 200 mg twice a day for 5 days.
Chronic suppressive therapy: Oral, 400 mg twice a day; or 200 mg 2 to 5 times a day.
• Creatinine clearance >10 ml/min: Oral, 400 mg twice a day.
• Creatinine clearance 0-10 ml/min: Oral, 200mg twice a day.
Oral, 800 mg 5 times a day for 7 to 10 days.
Creatinine clearance >25 ml/min, 800 mg 5 times a day for 7 to 10 days.
Creatinine clearance 10-25 ml/min, 800 mg twice a day for 7 to 10 days.
Creatinine clearance 0-10 ml/min, 800 mg twice a day for 7 to 10 days.
Oral, 20 mg per kg of body weight, up to 800 mg per dose, 4 times a day for 5 days.
Treatment should be initiated at the earliest sign or symptom of chickenpox
Oral, 200 to 400 mg 5 times a day for 10 days in immuno-compromised patients.
Children < 2 years : Dosage has not been established in children up to 2 years of age. However, no unusual toxicity or paediatric-specific problems have been observed in studies done in children using doses of up to 3000 mg/m2/day and 80 mg/kg/day
Children 2 to 12 years: Varicella: Oral 20 mg per kg of body weight, up to 800mg per dose, 4 times a day for 5 days. Treatment should be initiated at the earliest sign or symptom of chickenpox
Note: The information given here is limited. For further information consult your doctor or pharmacist.
Store below 25oC. Protect from light.
Tablet 200 mg x 100’s, blisters of 5 x 5’s
Tablet 400 mg x 10’s, blisters of 5 x 5’s
Manufactured / Batch Released by
HOVID Bhd., 121, Jalan Tunku Abdul Rahman, 30010 Ipoh, Malaysia.
Revision Date : December 2009