Valacyclovir
Antiviral, Systemic · DNA polymerase inhibitor
Indications
Herpes zoster. Treatment of herpes simplex infections of the skin and mucous membranes and suppression of recurrent infections. Treatment of initial and recurrent genital herpes.
Dosage
Herpes zoster: Adults: 2 tab three times daily for 7 days. Treatment of herpes simplex: Adults: First attack, 1 tab twice daily for 5-10 days starting as soon as possible after onset of lesions. Recurrent attacks: 1 tab twice daily for 5 days starting during prodromal period or as soon as possible after onset of lesions. Suppression in immunocompetent patients: 1/2 tab twice daily or 1 tab once daily if fewer than 10 recurrences per yr. Suppression in immunocompromised patients: 1 tab twice daily. Treatment of initial and recurrent genital herpes: Adults: 1 tab twice daily for 5-10 days, starting as soon as possible after onset of lesions. Children: Not recommended.
Adverse Effects
Headache, nausea, GI upset, dizziness, skin reactions.
Risk Factor (Pregnancy/Lactation)
Pregnancy: Risk cannot be ruled out. Lactation: Caution advised or effect undetermined. Contraindications: Complicated herpes zoster, immunocompromised patients with ocular herpes simplex or high risk of systemic involvement. Precautions: Renal impairment. Hepatic impairment, haemodialysis, elderly; monitor for neurological effects.
Interactions
Nephrotoxic drugs, iodinated contrast media, methotrexate, cyclosporin, foscarnet, tacrolimus, mycophenolate mofetil, aminoglycosides, pentamidine, platinum compounds. Agents that inhibit tubular secretion.
Advice to Patient
Take with or without meals. To prevent GI upset, take with meals. If you miss a dose, take it as soon as you remember unless it is nearly time for the next dose. Do not take double dose. Start treatment at the beginning of signs or symptoms of chicken pox. Inform prescriber immediately if there is difficulty in breathing or swallowing, hives, rash. Take sufficient amount of fluids (2-3 litres per day) to maintain hydration, unless restricted by the prescriber. Avoid contact with lesions or intercourse when lesions and/or symptoms are present to avoid infecting partners.
Pharmacokinetics
Absorption: Rapid. Metabolism: Hepatic. Bioavailability: Approx. 55% once converted to acyclovir. Half-life elimination: Normal renal function: Children: 1.3-2.5 hrs, slower clearance with increased age. Adults: Acyclovir: 2.5-3.3 hrs. Valaciclovir: Approx. 30 mins; End-stage renal disease: Acyclovir: 14-20 hrs; During haemodialysis: 4 hrs. Time to peak: Children: 1.4-2.6 hrs. Adults: 1.5 hrs. Excretion: Urine, primarily as acyclovir (89%).
Brands with this active ingredient
Compiled by Healify Pharmacy from published drug references. How we compile it →
Always consult a pharmacist or doctor.