VALTREX

What it is

Valtrex contains the active ingredient valaciclovir hydrochloride. The medicine is available as 500 mg and 1000 mg capsule-shaped film-coated tablets. 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 type 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 Valtrex to patients with impaired renal function, 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 transplant recipients at doses of 8 grams per day. Treatment with Valtrex 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 Valtrex treatment. Patients should be advised of the signs and symptoms and monitored closely for skin reactions. If signs and symptoms suggestive of DRESS appear, Valtrex should be withdrawn immediately and an alternative treatment considered.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. These events are usually seen in patients with renal impairment or with other predisposing factors. Valtrex should be discontinued if central nervous system adverse reactions occur. Renal insufficiency or acute renal failure has been observed in patients taking Valtrex at the recommended dosage and may be associated with renal pain. 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 for evidence of these effects.

Contraindications

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

PBS listing

Valtrex 500 mg tablets are listed on the PBS under 5 items with streamlined restriction status at an ex-manufacturer price of A$19.06.

Regulatory history

Valtrex was first registered on the ARTG on 4 May 2000 with four tablet variants: 250 mg, 500 mg, and 1000 mg formulations in both blister pack and bottle presentations.