Anderson G, Jariwalla A G, Al-Zaibak M
J Int Med Res. 1980;8(2):136-8. doi: 10.1177/030006058000800206.
A double-blind study of oral metoprolol and propranolol in nine patients with chronic bronchitis (Medical Research Council definition) showed no appreciable deterioration in lung function or significant differences between the two drugs.