BACKGROUND
Riluzole has been approved for treatment of patients with amyotrophic lateral sclerosis (ALS) in some countries but not others. Questions persist about its clinical utility because of high cost, modest efficacy and concern over adverse effects.
OBJECTIVES
To examine the efficacy of riluzole in prolonging survival, and in delaying the use of surrogates (tracheostomy and mechanical ventilation) to sustain survival.
SEARCH STRATEGY
Search of the Cochrane Neuromuscular Disease Group Register for randomized trials and enquiry from authors of trials and other experts in the field. The most recent search was conducted in June 1999.
SELECTION CRITERIA
Types of studies: randomized trials
TYPES OF PARTICIPANTS
adults with a diagnosis of ALS Types of interventions: treatment with riluzole or placebo Types of outcome measures: Primary: per cent mortality at 12 months with riluzole 100 mg Secondary: per cent mortality as a function of time with 100 mg and with all doses of riluzole, scales of neurologic function, quality of life, muscle strength and adverse events.
DATA COLLECTION AND ANALYSIS
We identified two randomized trials. Each reviewer graded them for methodological quality. Data extraction was performed by a single reviewer and checked by the other two. We obtained some missing data from investigators. We performed meta-analyses with RevMan software using a fixed effects model.
MAIN RESULTS
The two eligible trials included a total of 794 riluzole treated patients and 320 placebo treated patients. The methodological quality was acceptable and the trials were easily comparable. There were significant differences between the riluzole and placebo groups of both trials, in terms of the primary outcome measure, which was per cent mortality at 12 months with the 100 mg dose of riluzole. The odds ratio for the combined studies was 0.57 (95%CI 0.41 to 0.80) at 12 months. In the secondary outcome measures, there was a survival advantage with riluzole 100 mg at six, nine, 12 and 15 months, but not at three or 18 months. Pooled data from the 50, 100 and 200mg dose groups in the larger trial showed a lower per cent mortality with riluzole compared to placebo only at 12 months (odds ratio (OR) 0.64, 95% CI 0.47 to 0.88). There was no beneficial effect on bulbar function, or muscle strength. There were scant data on quality of life, but patients treated with riluzole remained in a more moderately affected health state significantly longer than placebo-treated patients (weighted mean difference (WMD) 35.5 days, 95% CI 5.9 to 65. 0). A threefold increase in serum alanine transferase was more frequent in riluzole treated patients than controls (WMD 2.65, 95% CI 1.51 to 4.65).
REVIEWER'S CONCLUSIONS
Riluzole 100 mg per day appears to be modestly effective in prolonging survival for patients with ALS.