VALACICLOVIR-WGR

What it is

VALACICLOVIR-WGR contains the active ingredient valaciclovir hydrochloride. The medicine is available as film-coated tablets in two strengths: 500 mg and 1000 mg. Valaciclovir is rapidly and almost completely converted in the body to aciclovir. Aciclovir is a specific inhibitor of herpes viruses with activity against herpes simplex viruses type 1 and 2, varicella-zoster virus, and human cytomegalovirus.

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

Caution is advised when administering VALACICLOVIR-WGR to patients with impaired renal function and adequate hydration should be maintained. In elderly patients, dose reduction must be considered due to the possibility of renal impairment and adequate hydration should be maintained.

Key safety warnings

Thrombotic thrombocytopenic purpura or haemolytic uraemic syndrome (TTP/HUS), in some cases resulting in death, has occurred in patients with advanced HIV disease treated with valaciclovir for prolonged periods and in allogeneic bone marrow transplant and renal 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 If signs and symptoms suggestive of DRESS appear, valaciclovir should be withdrawn immediately and an alternative treatment considered. If the patient has developed DRESS with the use of valaciclovir, treatment with valaciclovir must not be restarted at any time. 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 in patients with renal impairment or with other predisposing factors. In organ transplant patients receiving high doses (8 g daily) for CMV prophylaxis, neurological reactions occurred more frequently. Valaciclovir should be discontinued if central nervous system adverse reactions occur. Renal insufficiency or acute renal failure has been observed in patients taking valaciclovir at recommended dosage with no previous renal conditions. The dose must be reduced in patients with renal impairment. Patients with renal impairment are at increased risk of developing neurological side effects and should be closely monitored; these reactions were generally reversible on discontinuation of treatment.

Contraindications

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

Regulatory history

VALACICLOVIR-WGR was first registered on the Australian Register of Therapeutic Goods on 2 July 2020, with three variant registrations for 500 mg tablets in blister pack and bottle formats and 1000 mg tablets in blister pack format.