Propranolol also was used in testing the bronchular sensitivity of normal and asthmatic or allergic patients to methacholine and histamine by Gerald Zaid, MD.
In normal humans, beta adrenergic blockade did not increase this sensitivity. A variable response was seen in patients with allergic rhinitis.
Marked sensitivity increases to methacholine were observed in asthmatics. But, because of the lack of response in normal subjects—despite considerable blockade—the role of partial beta blockage in asthmatic etiology was questioned.
Nevertheless, because of the marked parasympathetic response, propranolol should not be administered to asthmatics with angina or cardiac arrhythmias, concluded Dr. Zaid. He conducted his studies with Gildon N. Beall, MD, also of Los Angeles.