Nebivolol and airway responsiveness in the rabbit

Beta-adrenergic receptor antagonists are currently used as first-line thera py in the treatment of hypertension and angina pectoris, but are contraindi cated or used with caution in patients with bronchospastic syndromes. In th is study we evaluated in vivo the effects of nebivolol on airway responsive ness compared to atenolol, pindolol, and propranolol. In New Zealand white rabbits total lung resistance (R-L) and dynamic compliance (C-dyn) were cal culated. In acute protocol, the animals were intravenously injected with th e beta -blockers at different doses while in the chronic protocol, animals were daily injected for 30 days. Furthermore, the changes induced by beta - blockers (higher doses) in R-L and C-dyn after a treatment with salbutamol were calculated. In acute treatment, airway responsiveness to histamine was not modified by nebivolol at any dosage, but increased significantly follo wing the exposure to the higher doses of the other beta -blockers. In chron ic treatment, the thirty-day exposure to nebivolol did not modify the airwa y responsiveness to histamine, whereas the other beta -blockers significant ly increased airway responsiveness. Moreover, nebivolol affected the salbut amol-induced relaxation less markedly than other beta -blockers do. These d ata demonstrate that nebivolol respect the other beta -blockers used in thi s study, does not significantly affect the airway responsiveness, therefore it could be used in patients with both cardiovascular and bronchial diseas es more safely than other beta -blockers drugs. (C) 2001 Elsevier Science I nc. All rights reserved.