Effect of intravenous metoprolol on reversible obstructive airways disease

We gave increasing doses of metoprololintravenously to seven subjects with stable chronic obstructive pulmonary disease (COPD) who were also receiving their usual bronchodilators. Six of the seven tolerated up to 0.2 mg/kg metoprolol without adverse effects, although there were declines in forced expiratory volume in 1 sec (FEV₁) At 0.15 mg/kg mean FEV₁ fell 12% (p < 0.025), and at 0.2 mglkg mean decline in FEV₁ was 15% (p < 0.01). These findings suggest that 0.2 mg/kg metoprolol may be given intravenously to most patients with COPD in addition to previously administered bronchodilators without precipitating clinically significant adverse effects. Any side effects that develop can be reversed by beta agonists.