Tolerability, administration burden, and patient-reported experience of riluzole formulations in ALS: a longitudinal real-world study

Introduction Riluzole is available as tablets (T), oral suspension (OS), and orodispersible film (OF), but comparative real-world data on tolerability, administration burden, and patient-reported experience are limited. Methods In this longitudinal study, 138 patients with amyotrophic lateral sclerosis (ALS) were evaluated at baseline (79 OF, 21 OS, 38 T) and 97 were reassessed after a median of 3.9 months. Results OS-treated patients had longer disease duration and greater functional impairment than OF or T (p < 0.001), reflecting preferential use in more advanced disease. Oral numbness was more frequent with OF than OS or T (54.4% vs. 14.3% vs. 13.2%; p < 0.001) and decreased during follow-up (42.3%–28.9%; p = 0.016), partly because patients reporting it switched away from OF. OF use (adjusted OR 10.55 vs. T, p < 0.001) and female sex (OR 2.59, p = 0.035) were independently associated with higher, and older age with lower, odds of an adverse event at baseline (OR 0.43 per 10-year increment, p < 0.001); at 3-month follow-up, OF remained the strongest formulation-related predictor (OR 5.42, p = 0.024), while an adverse event already present at baseline was itself the strongest predictor of one at follow-up (OR 5.11, p = 0.006). Dysphagia was associated with tablet manipulation (OR 7.19, p = 0.034). Differences among formulations concerned packaging convenience and independent self-administration rather than overall satisfaction, and lower disease severity was weakly associated with higher satisfaction regardless of formulation (ρ = 0.21, p = 0.015). Formulation persistence among reassessed patients was high (85.6%), and most patients who left OF had anticipated this intention at baseline. Discussion The three riluzole formulations are used in clinically distinct ALS populations and differ in tolerability and usability rather than overall satisfaction, and a prior adverse event marks persisting risk. Formulation choice should be individualized and periodically reassessed as disease progresses.