The effect of salbutamol on bronchoconstriction induced by inhaled sodium metabisulphite has been studied in 12 atopic subjects. Salbutamol (200 micrograms, 3.5 x 10(-7) M) and matched placebo were administered by identical metered dose inhaler 15 min before a dose-response to sodium metabisulphite (1.25-100 mg ml-1) was performed. Geometric mean provocative dose of metabisulphite causing a 35% fall in sGaw after placebo pretreatment was 12.8 [5.75-28.1, 95% Cl] mumol, and after salbutamol was 75.9 [46.5-126] mumol. Mean maximum fall in sGaw after placebo pre-treatment was 47.4 [41-53.9]%. At the same metabisulphite concentration mean maximum fall in sGaw after salbutamol was 2.9 [-8.2-14.1]%.