RILUTEK

What it is

Riluzole is a benzothiazole active ingredient available as a 50 mg film-coated tablet. The tablets are white, capsule-shaped, and debossed with the text 'RLZ' on one side.

Approved indications —

Amyotrophic lateral sclerosis (ALS)

Dosing overview

The recommended daily dose in adults or elderly is 100 mg (50 mg every 12 hours). No significant increase in benefit can be expected from higher daily doses. Due to the reduction in absorption observed when administered with high fat meals, riluzole should not be taken with a fat-containing meal.

Key safety warnings

Cases of marked neutropenia with absolute neutrophil count less than 500/mm³ have been reported. Patients should be warned to report any febrile illness to their physicians, and the report of a febrile illness should prompt physicians to check white blood cell counts and to discontinue riluzole in case of neutropenia. Cases of interstitial lung disease have been reported in patients treated with riluzole, some of them severe. If respiratory symptoms develop such as dry cough and/or dyspnoea, chest radiography should be performed, and in case of findings suggestive of interstitial lung disease, riluzole should be discontinued immediately. Elevations of alanine-aminotransferase (ALT) levels to more than 3 times the upper limit of normal were observed in about 10% of patients treated with riluzole; increases appeared within 3 months and were usually transient. Because of risks of hepatitis, serum transaminases should be measured before and during therapy, with ALT measured every month during the first 3 months, every 3 months during the remainder of the first year, and periodically thereafter.

Contraindications

Patients with a history of severe hypersensitivity reactions to riluzole or any tablet component should not use this medicine. Riluzole is contraindicated in patients with hepatic disease or hepatic impairment with baseline transaminases greater than 3 times the upper limit of normal. Riluzole must not be used in pregnant women or during lactation.

PBS listing

In November 2018, the Pharmaceutical Benefits Scheme recommended listing of a liquid formulation of riluzole for amyotrophic lateral sclerosis, with an Authority Required restriction.

Regulatory history

Riluzole 50 mg tablets were first listed on the Australian Register of Therapeutic Goods on 13 May 2002. In November 2018, PBAC recommended a new liquid formulation for PBS listing with an Authority Required restriction for amyotrophic lateral sclerosis.