isoprenaline
Last reviewed 01/2018
Isoprenaline has beta-1- and beta-2-adrenoceptor activity, and thus acts to markedly improve cardiac output. However, after some years of use of this drug there was a gradual increase in the number of sudden deaths after surgery, probably reflecting an increase in age of the population undergoing surgery. The older population has poorer coronary vessels and is thus unable to increase blood flow in vessels so much.
Increased heart rate and arterial pressure with isoprenaline reduces perfusion pressure and duration of diastole, and results in poor blood flow to myocardium with subsequent damage. Slowed conduction through ischaemic areas results in arrhythmias.
It is used in circulatory failure associated with bradycardia and in heart block, and also in situations where there is excessive vasoconstriction.