For the management of hypertension.
Betaxolol selectively blocks catecholamine stimulation of beta(1)-adrenergic receptors in the heart and vascular smooth muscle. This results in a reduction of heart rate, cardiac output, systolic and diastolic blood pressure, and possibly reflex orthostatic hypotension. Betaxolol can also competitively block beta(2)-adrenergic responses in the bronchial and vascular smooth muscles, causing bronchospasm.
Oral LD<sub>50</sub>s are 350 to 400 mg betaxolol/kg in mice and 860 to 980 mg/kg in rats. Predicted symptoms of overdose include bradycardia, congestive heart failure, hypotension, bronchospasm, and hypoglycemia.
Absorption of an oral dose is complete. There is a small and consistent first-pass effect resulting in an absolute bioavailability of 89% &plusmn; 5% that is unaffected by the concomitant ingestion of food or alcohol.
14-22 hours