Nadolol and labetalol: comparative efficacy of two beta-blocking agents in glaucoma.

The beta-blocking agent Nadolol and the beta- and alpha-blocking agent Labetalol were screened for their potential efficacy on intraocular pressure (IOP) in glaucoma. Nadolol 2% and Labetalol 1% in aqueous solution were investigated in a single-dose manner on the basis of a double-masked clinical trial. Only Nadolol reduced IOP significantly which was maximal 4 h after drug application and had a duration of action of at least 6 h and less than 24 h. Blood pressure, pulse rate, and pupil diameter were not significantly affected, and Labetalol did not change either parameter significantly. It is concluded that Nadolol may be of use in glaucoma therapy.