The effect of amitriptyline on forearm blood flow

The local effect of intra-arterial infusion of amitriptyline (AT) on forearm blood flow was studied in seven healthy subjects. AT was infused at rates of 0.05, 0.10, 0.15, and 0.20 mg-min--1 for periods of 5 min. Forearm blood flow showed a dose-dependent increase when the dose exeeded 0.10 mg-min--1. On the highest dose level the blood flow increased on an average by 73%. No systemic effects, as reflected by changes in heart rate, blood pressure, and blood flow in the contralateral forearm, were observed during the infusion. The present data indicate a dilatating effect of AT on resistance vessels possibly mediated by an alpha-adrenergic blockade.