Cardioselectivity of atenolol and metoprolol. A study in asthmatic patients.

Eight asthmatic patients were investigated in a double-blind cross-over study after oral administration of 100 mg atenolol, 10 mg metoprolol and placebo. Four increasing doses of terbutaline (0.036-1.23 micrograms kg-1 min-1) were thereafter administered by intravenous infusion, starting 120 min after the tablet intake. The infusions were given for 6 min on each dose level with 30-min intervals. The study was finished by inhalation of six terbutaline puffs (1.5 mg). Both atenolol and metoprolol lowered resting heart rate and FEV1 significantly and produced a down- and rightward shift of the dose-response curves to infused terbutaline. No differences between effects of the two beta-blockers were shown in reduction of heart rate and FEV1, before and during the terbutaline treatments. Differences in cardioselectivity between atenolol and metoprolol could thus not be shown.

RCT Entities:   Population Interventions Outcomes