The effects of oral AH 5158, a combined α and β-adrenoceptor antagonist, in healthy volunteers.

1 In healthy male volunteers after single oral doses, AH 5158 produced inhibition of exercise induced tachycardia, falls in systolic and diastolic pressure at rest and in response to exercise, which are probably related to combined β- and α-adrenoceptor antagonism. 2 At increasing doses from 100 mg to 400 mg there exists a dose related antagonistic effect, though the dominant effect of β-adrenoceptor antagonism is more easily demonstrable than is α antagonism. 3 As indicated by the pattern of pharmacological effects, absorption of the oral drug is good and the duration of action of a 400 mg dose is approximately 8 hours. 4 Despite being administered in β-adrenoceptor blocking doses, AH 5158 had no adverse effects upon peak expiratory flow at rest or in response to exercise. 5 It is concluded that the pharmacological profile of this combined α- and β-adrenoceptor antagonism suggests a potential therapeutic role as an antihypertensive drug.