Riluzole for motor neurone disease

An editorial in the MJA describes the glutamate antagonist riluzole as "a glimmer of hope in the treatment of motor neurone disease".The editorial, by Dr Matthew Kiernan of Sydney's Prince of Wales Hospital, provides a brief overview of the drug's postulated effects on glutamate receptors and neuronal sodium ion channels. It also describes results of trials in motor neurone disease (MND), which showed the drug provided a significant survival benefit of between 3-6 months and improvement in functional outcome measures.Dr Kiernan says, "Riluzole remains the only medication to slow the progression of a neurodegenerative disease, leading to an increased survival for patients with MND." He suggests that early initiation of therapy is preferable, given the potential neuroprotective properties of the drug. However, the author adds, "...there is no evidence to suggest that riluzole reverses motor neurone degeneration and, despite extensive counselling about what to expect, patients may have unrealistic expectations of riluzole therapy." He adds that patients must be adequately informed that the goal of treatment is to slow the rate of muscle function deterioration, and not to improve symptoms, as some patients may discontinue therapy, believing it's providing no benefit.A full blood count is suggested before initiation of therapy, as blood dyscrasias can occur rarely with riluzole. Monthly liver function tests during the first three months of therapy and then at three monthly intervals are also important, due to the small risk of hepatotoxicity with therapy.The date of MND diagnosis and the results of respiratory testing must be supplied with the initial authority application. PBS approval is for patients aged 75 years or less, with disease duration of 2 years or less and who have at least 60% of predicted forced vital capacity within two months prior to the drug's commencement. Full PBS criteria are provided in the editorial.Reference...