Investigation of salbutamol tolerance.

1 A double blind cross-over study was carried out on patients with reversible airways disease attending an out-patient clinic. 2 Twenty patients were given either salbutamol (200 μg) or propellant by aerosol for two week periods and in another study twelve patients were given identical tablets containing either salbutamol (4 mg) or placebo for four week periods. Both forms of therapy were taken four times per day but stopped the evening before attending the clinic. 3 The improvement in FEV(1) 10 min following salbutamol (200 μg) by aerosol was measured after previous treatment with either salbutamol or placebo administered by aerosol and orally and the results were compared statistically. This failed to show a significant difference and suggests that regular treatment with salbutamol does not lead to a decreased response.