Introna A, et al. - This observational study was designed to assess the adherence to 2 formulations of riluzole in patients with amyotrophic lateral sclerosis (ALS). The most frequent side effects (SEs) related to the tablet as well as the oral suspension (OS) were gastroenteric symptoms. The rate of adherence was independent of the formulation of riluzole and the number of medications assumed for comorbidities. The rate of adherence was consistent with the severity of the disease. In the tablet group, the low adherence was caused by dysphagia and SEs, while it was caused prevalently by SEs in the OS group.