title: Comparison of the efficacy and systemic effects of 4 mg and 8 mg formulations of salbutamol controlled release in patients with asthma.
abstract: The purpose of the present study was to compare the efficacy and systemic effects of 4 mg and 8 mg doses of salbutamol controlled release (SCR) after single dosing and at steady state in patients with asthma. Fifteen asthmatic patients (Age 36 y, FEV1 85% predicted) were given SCR 4 mg and 8 mg twice daily for 7 days in a randomised double-blind cross-over design, with at least 7 days washout between treatments. There were no differences between the bronchodilator effects of 4 mg and 8 mg doses. There was no evidence of tolerance to the bronchodilator effects after chronic dosing. Morning and evening PEFR measurements also showed improvements during treatment with SCR 4 mg and SCR 8 mg, although there were no differences between the two formulations. Both doses of SCR caused significant objective tremor responses which were maintained after chronic dosing. The 8 mg dose produced a larger tremor response after single dosing, but not at steady-state. Subjective tremor occurred in 7 patients with SCR 8 mg, and in 2 patients with SCR 4 mg. There were no cardiac arrhythmias on Holter ECG monitoring. These results suggest that the 8 mg dose of SCR was no more effective than the 4 mg formulation, and was associated with more systemic adverse effects.
authors: Department of Clinical Pharmacology, Ninewells Hospital and Medical School, Dundee, UK.
authors: B J
authors: BJ
authors: Lipworth
authors: R A
authors: RA
authors: Clark
authors: D P
authors: DP
authors: Dhillon
authors: J B
authors: JB
authors: Palmer
authors: D G
authors: DG
authors: McDevitt
mesh_terms: D000328:Adult; D000420:Albuterol / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D001249:Asthma / Q000188:drug therapy*; D003692:Delayed-Action Preparations; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D005260:Female; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D010366:Peak Expiratory Flow Rate / Q000187:drug effects; D016032:Randomized Controlled Trials as Topic; D014797:Vital Capacity / Q000187:drug effects
chemical_list: D003692:Delayed-Action Preparations; D000420:Albuterol