ZELITREX

What it is

ZELITREX contains the active ingredient valaciclovir hydrochloride. It is supplied 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 (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

Caution is advised when administering ZELITREX to patients with impaired renal function, and adequate hydration should be maintained. Elderly patients are likely to have reduced renal function and dosage should be adjusted accordingly, with adequate hydration 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 and renal transplant recipients receiving high 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 ZELITREX treatment. Patients should be advised of the signs and symptoms and monitored closely for skin reactions. If signs and symptoms suggestive of DRESS appear, ZELITREX should be withdrawn immediately and an alternative treatment considered.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. 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 ZELITREX at the recommended dosage and/or with no previous renal conditions and may be associated with renal pain. Cases of acute renal failure have been reported in patients without adequate hydration. Adequate hydration should be maintained for all patients. Care should be taken to ensure adequate fluid intake in patients at risk of dehydration, particularly the elderly. Adequate hydration should be maintained for all patients.

Contraindications

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

PBS listing

ZELITREX 500 mg tablet is listed on the PBS as one item with streamlined restriction at an ex-manufacturer price of A$4.00.

Regulatory history

ZELITREX valaciclovir 500 mg tablet was first registered on the Australian Register of Therapeutic Goods (ARTG 128739) on 28 February 2007. A second ARTG entry (ARTG 198610) for the 500 mg tablet in bottle form was registered on 30 August 2012.