BACKGROUND: Amyotrophic lateral sclerosis is a progressive motor neuron disease for which there is no adequate treatment. Some research suggests that the excitatory amino acid neurotransmitter glutamate may be involved in the pathogenesis. METHODS: To evaluate the efficacy and safety of the antiglutamate agent riluzole, we conducted a prospective, double-blind, placebo-controlled trial in 155 outpatients with amyotrophic lateral sclerosis. The dose of riluzole was 100 mg per day. Randomization was stratified according to the site of disease onset (the bulbar region or the limbs). The primary end points were survival and rates of change in functional status. The main secondary end point was change in muscle strength. Analyses were undertaken after 12 months of treatment and at the end of the placebo-controlled period (median follow-up, 573 days). RESULTS: After 12 months, 45 of 78 patients (58 percent) in the placebo group were still alive, as compared with 57 of 77 patients (74 percent) in the riluzole group (P = 0.014). For patients with bulbar-onset disease, one-year survival rates were 35 percent (6 of 17) with placebo and 73 percent (11 of 15) with riluzole (P = 0.014), whereas for those with limb-onset disease one-year survival was 64 percent and 74 percent, respectively (P = 0.17). The survival advantage with riluzole was smaller (37 percent [29 of 78] with placebo vs. 49 percent [38 of 77] with riluzole) at the end of the placebo-controlled period, but it remained significant in the overall population (P = 0.046) as well as in the patients with bulbar-onset disease (18 percent [3 of 17] vs. 53 percent [8 of 15], P = 0.013). The deterioration of muscle strength was significantly slower in the riluzole group than in the placebo group (P = 0.028). Adverse reactions to riluzole included asthenia, spasticity, and mild elevations in aminotransferase levels. Twenty-seven patients in the riluzole group withdrew from the study, as compared with 17 in the placebo group. CONCLUSIONS: The antiglutamate agent riluzole appears to slow the progression of amyotrophic lateral sclerosis, and it may improve survival in patients with disease of bulbar onset.

ALS is a progressive motor neuron disease with no effective treatment. The anti-excitotoxic drug riluzole (100 mg/day) has been shown to decrease mortality and muscular deterioration in ALS patients. To confirm and extend the therapeutic effect of riluzole, we performed a double-blind, placebo-controlled, multicenter, international, dose-ranging (50, 100, 200 mg/day), stratified study in 959 ALS outpatients treated for up to 18 months. Primary efficacy criterion was survival and the effect of treatment was analyzed before (Wilcoxon and log rank tests) and after adjustment on prognostic factors (Cox model). Secondary efficacy criterion was disease progression assessed through change in functional measures. Tracheostomy-free survival rates were: 50.4% (placebo), 55.3% (50 mg riluzole) (p = 0.23, Wilcoxon test; p = 0.25, log-rank test), 56.8% (100 mg riluzole) (p = 0.05, Wilcoxon test; p = 0.076, log-rank test), and 57.8% (200 mg riluzole) (p = 0.061, Wilcoxon test; p = 0.075, log-rank test). At the end of the 18-month study, there was a significant dose-related decrease in risk of death or tracheostomy (p = 0.04). Adjustment for baseline prognostic factors showed a 35% decreased risk of death with the 100-mg dose compared with placebo (p = 0.002). No significant treatment effects were detected for the functional assessments. The most frequent dose-related adverse events included nausea, asthenia, and elevated liver enzyme levels. This study confirms the therapeutic effect of riluzole in a large representative ALS sample, over an 18-month period. Riluzole is well tolerated and decreases the risk of death or tracheostomy in ALS patients.

OBJECTIVE: To provide a comprehensive review of riluzole, including its mechanism of action, pharmacokinetics, adverse drug reactions, drug interactions, efficacy, and administration. A brief review of amyotrophic lateral sclerosis (ALS) is also included. DATA SOURCES: A computerized search of the MEDLINE database in May 1996 was used to identify publications regarding ALS, riluzole, and metabolism by CYP1A2. Manufacturer's information on riluzole was used when there was no primary literature. DATA SYNTHESIS: Riluzole is approximately 90% absorbed following an oral dose. Its bioavailability is 60%. Peak concentrations occur within 1-1.5 hours of administration. Riluzole extensively binds to lipoproteins and albumin. This agent primarily undergoes CYP1A2 hydroxylation and glucuronidation, after which it is eliminated by the kidneys. Clearance is reduced in native Japanese healthy subjects and may be reduced in patients with hepatic impairment. Two trials with a total of 1114 patients addressed the efficacy of riluzole in ALS. Riluzole extended the time to tracheostomy or death, and the effect was greatest with dosages of 100 mg/d or greater. No effect on patients' symptoms or global assessment was detected at 18 or 21 months. Several flaws in these trials have led to questions concerning the validity of these results. The most commonly reported adverse effects of riluzole have been transient elevation of liver enzyme concentrations (2-5 times the upper limit of normal), worsening of asthenia, nausea, vomiting, diarrhea, anorexia, dizziness, vertigo, somnolence, and mouth paresthesia. Not as commonly reported, but still very serious, is neutropenia, which occurred in 3 of 4000 patients. CONCLUSIONS: Although the benefits of riluzole are questionable and it is expensive, this agent may extend the time to tracheostomy or death in patients with ALS. At present, this is the only agent approved for the treatment of ALS and should be made available for these patients.

RECORD STATUS: None CITATION: Booth-Clibborn N, Best L, Stein K. Riluzole for motor neurone disease. Southampton: Wessex Institute for Health Research and Development (WIHRD) 1997

BACKGROUND: Amyotrophic lateral sclerosis (ALS) is a progressive disease with no effective treatment. In an initial study, riluzole decreased mortality and slowed muscle-strength deterioration in ALS patients. We have carried out a double-blind, placebo-controlled, multicentre study to confirm those findings and to assess drug efficacy at different doses. METHODS: 959 patients with clinically probable or definite ALS of less than 5 years' duration were randomly assigned treatment with placebo or 50 mg, 100 mg, or 200 mg riluzole daily; randomisation was stratified by centre and site of disease onset (bulbar or limb). The primary outcome was survival without a tracheostomy. Secondary outcomes were rates of change in functional measures (muscle strength, functional status, respiratory function, patient's assessments of fasciculation, cramps, stiffness, and tiredness). The primary analysis was the comparison of the 100 mg dose with placebo by intention-to-treat. Drug-effect on survival was assessed before (log-rank test) and after adjustment for known prognostic factors (Cox's model). FINDINGS: At the end of the study, after median follow-up of 18 months, 122 (50.4%) placebo-treated patients and 134 (56.8%) of those who received 100 mg/day riluzole were alive without tracheostomy (unadjusted risk 0.79, p = 0.076; adjusted risk 0.65, p = 0.002). In the groups receiving 50 mg and 200 mg riluzole daily, 131 (55.3%) and 141 (57.8%) patients were alive without tracheostomy (relative to placebo 50 mg adjusted risk 0.76, p = 0.04; 200 mg 0.61, p = 0.0004). There was a significant inverse dose response in risk of death. No functional scale discriminated between the treatment groups. The most common adverse reactions were asthenia, dizziness, gastrointestinal disorders, and rises in liver enzyme activities; they were commonest with the 200 mg dose. INTERPRETATION: Overall, efficacy and safety results suggest that the 100 mg dose of riluzole has the best benefit-to-risk ratio. This study confirms that riluzole is well tolerated and lengthens survival of patients with ALS.

BACKGROUND: Riluzole is approved for the treatment of amyotrophic lateral sclerosis in most countries. Questions persist about its clinical utility because of high cost and modest efficacy. OBJECTIVES: To examine the efficacy of riluzole in prolonging survival and in delaying the use of surrogates (tracheostomy and mechanical ventilation) to sustain survival, and to assess the effect of riluzole upon functional health. SEARCH METHODS: We searched the Cochrane Neuromuscular Disease Group Specialized Register (20 April 2011), the Cochrane Central Register of Controlled Trials (CENTRAL) (2011, Issue 2), MEDLINE (1966 to April 2011), EMBASE (1980 to May 2011) and made enquiries of authors of trials, Aventis (manufacturer of riluzole) and other experts in the field. SELECTION CRITERIA: Types of studies: randomized controlled trials Types of participants: adults with a diagnosis of amyotrophic lateral sclerosis Types of interventions: treatment with riluzole or placebo Types of outcome measures: Primary: pooled hazard ratio of tracheostomy-free survival over all time points with riluzole 100 mg. Secondary: per cent mortality with riluzole 50 mg, 100 mg and 200 mg; neurologic function, muscle strength and adverse events. DATA COLLECTION AND ANALYSIS: One author performed data extraction and two other authors checked them. One author checked the data and entered them into the computer. The other authors verified the data entry. We obtained missing data from the trial authors whenever possible. MAIN RESULTS: The four trials examining tracheostomy-free survival included a total of 974 riluzole-treated patients and 503 placebo-treated patients. No new randomized controlled trials were found when we updated the searches for this update in 2011. The methodological quality was acceptable and three trials were easily comparable, although one trial (169 participants) included older patients in more advanced stages of amyotrophic lateral sclerosis and one (195 participants) had multiple primary endpoints. Riluzole 100 mg per day provided a benefit for the homogeneous group of patients in the first two trials (hazard ratio (HR) 0.80, 95% confidence internal (CI) 0.64 to 0.99, P= 0.042) and there was no evidence of heterogeneity (P = 0.33). When the third trial (which included older and more seriously affected patients) was added, there was evidence of heterogeneity (P < 0.0001) and the overall treatment effect was reduced but still significant (HR 0.84, 95% CI 0.698 to 0.997, P= 0.046). This represented a 9% gain in the probability of surviving one year (49% in the placebo and 58% in the riluzole group), and increased median survival from 11.8 to 14.8 months. There was a small beneficial effect on both bulbar and limb function, but not on muscle strength. A three-fold increase in serum alanine transferase was more frequent in riluzole-treated patients than controls (mean difference 2.62, 95% CI 1.59 to 4.31). AUTHORS' CONCLUSIONS: Riluzole 100 mg daily is reasonably safe and probably prolongs median survival by about two to three months in patients with amyotrophic lateral sclerosis.

RECORD STATUS: None CITATION: Jensen S F S, Kristensen F B, Sigmund H, Thorsen T. Between hope and despair: ALS patients and riluzole. Danish Institute for Health Services Research (DSI). DSI rapport 98.03. 1998

CRD COMMENTARY: The summary mentions only 2 large scale trials, and it is unclear whether there are other smaller trials which have not been included in the review. Also, the search is limited and searches of other databases (e.g. EMBASE) would have uncovered other relevant studies. There are few methodological details relating to the review itself. It is therefore unclear whether the results of the review are robust. As there are only 2 large trials included, the conclusions of the review may be susceptible to publication bias.

RECORD STATUS: None CITATION: Scottish Health Purchasing Information Centre. Riluzole for motor neurone disease. Briefing note Scottish Health Purchasing Information Centre (SHPIC). 1996

Executive summary available for free by visiting the document URL listed with this record.