The effect of bunazosin hydrochloride on intraocular pressure and aqueous humor dynamics in human]

The effects of bunazosin hydrochloride, a new highly selective alpha 1 adrenergic antagonist, on the intraocular pressure (IOP) and aqueous humor dynamics in healthy human volunteers were studied. Unilateral topical administration of 0.1% bunazosin significantly lowered IOP from 1 to 10 hrs in bunazosin-treated eyes, and from 2 to 8 hrs in contralateral placebo-treated eyes, with its maximum reduction at approximately 3 hrs, when the IOP decreased 5.0 mmHg in treated eyes, and 3.5 mmHg in contralateral eyes from the baseline, respectively. Fluorophotometrically measured aqueous humor flow rates did not change significantly either in treated or contralateral eyes. Bunazosin caused significant reduction of systolic and diastolic blood pressure 5 hr after application. The difference in pupil diameter between treated and contralateral eyes was found to be statistically significant from 1 to 5 hrs. A small but significant increase in anterior chamber depth also was observed from 2 to 6 hrs. Pulse rate and refraction were not substantially altered. There was moderate conjunctival vessel dilation, however, no serious complications were encountered. The results suggest that bunazosin hydrochloride appears to have great clinical potential for ocular hypotensive therapy.