VACLOVIR

What it is

Vaclovir contains the active ingredient valaciclovir hydrochloride. Vaclovir is available as 500 mg and 1000 mg film-coated tablets. Valaciclovir is rapidly and almost completely converted in the body to aciclovir. Aciclovir is a specific inhibitor of the herpes viruses with in vitro activity against herpes simplex viruses (HSV) type 1 and type 2, varicella-zoster virus (VZV) and human cytomegalovirus (HCMV).

Approved indications

— Treatment of herpes zoster (shingles) in adult patients who commence therapy within 72 hours of the onset of rash. — Treatment of ophthalmic zoster. — Treatment of recurrent herpes labialis (cold sores). — Treatment of clinical episodes of genital herpes simplex infections. — Prevention of recurrent genital herpes. — Reduction of transmission of genital herpes in patients suffering from recurrent genital herpes. — Prophylaxis of cytomegalovirus (CMV) infection and disease following solid organ transplantation in patients at risk of CMV disease.

Dosing overview

For herpes zoster: 1000 mg of valaciclovir three times a day for seven days. For cold sores: 2000 mg twice daily for 1 day, with the second dose taken about 12 hours (no sooner than 6 hours) after the first dose. For genital herpes, first clinical presentation is 500 mg twice a day for 5 to 10 days; for recurrent episodes, 500 mg twice daily for 5 days. For prevention of genital herpes in patients with fewer than 10 recurrences each year: 500 mg once daily; in patients with 10 or more recurrences each year: 1000 mg once daily. For prophylaxis of cytomegalovirus infection and disease: 2 g four times a day for 90 days in adults and adolescents from 12 years of age, initiated as early as possible post-transplant.

Key safety warnings

Thrombotic thrombocytopenic purpura or haemolytic uraemic syndrome (TTP/HUS) has occurred in patients with advanced HIV disease treated with valaciclovir for prolonged periods and in organ transplant recipients treated at doses of 8 grams per day. Treatment should be stopped immediately if clinical signs, symptoms, and laboratory abnormalities consistent with TTP/HUS occur. Drug reaction with eosinophilia and systemic symptoms (DRESS), which can be life-threatening or fatal, has been reported in association with valaciclovir treatment. Patients should be advised of the signs and symptoms and monitored closely for skin reactions. If signs and symptoms suggestive of DRESS appear, valaciclovir should be withdrawn immediately and an alternative treatment considered. Reversible neurological reactions including agitation, dizziness, confusion, hallucinations, rarely decreased consciousness and very rarely tremor, ataxia, dysarthria, convulsions, encephalopathy and coma have been reported, usually seen in patients with renal impairment or with other predisposing factors. Patients with renal impairment are at increased risk of developing neurological side effects and should be closely monitored for evidence of these effects. Renal insufficiency or acute renal failure has been observed in patients taking valaciclovir at the recommended dosage and/or with no previous renal conditions. The dose of valaciclovir must be reduced in patients with renal impairment. Care should be taken to ensure adequate fluid intake in patients who are at risk of dehydration, particularly the elderly. Adequate hydration should be maintained for all patients.

Contraindications

Vaclovir is contraindicated in patients known to be hypersensitive to valaciclovir, aciclovir or any component of the formulation.

PBS listing

No information regarding PBS listing, strength, item count, restriction type or ex-manufacturer price is available in the provided documents.

Regulatory history

Vaclovir 500 mg tablets in blister and bottle packs and 1000 mg tablets in blister packs were first listed on the ARTG on 4 November 2010.