RESUMO
OBJECTIVE: To evaluate the effects on muscle strength of salbutamol administered for 6 months using a periodic regimen in patients presenting with facioscapulohumeral muscular dystrophy (FSHD). DESIGN: Placebo-controlled double-blind randomized study. SETTING: Three clinical centers involved in neuromuscular disorders. PARTICIPANTS: Ambulatory patients (N=112), 56 per group, with genetically confirmed FSHD, age 18 to 60 years. INTERVENTIONS: Salbutamol (sustained released formulation) administered orally at a daily dose of 16 mg using a periodic dosage regimen (3 wks on, 1 wk off). MAIN OUTCOME MEASURES: Muscle strength was assessed with quantitative muscle testing (QMT), manual muscle testing (MMT), and timed motor tests. Patients were evaluated at baseline, and 3 and 6 months later. Plasma drug assays were carried out at each visit. RESULTS: There was no significant change with periodic use of salbutamol in the total composite QMT z-score, MMT score, or timed motor tests. Salbutamol was well tolerated. Lack of efficacy did not seem to be related to plasma concentrations, which were within the expected range. CONCLUSIONS: Results from this study and previous controlled trials preclude at present the use of salbutamol as routine treatment for FSHD, even if we cannot exclude improvement from anabolic effects with a longer duration of treatment.
