(Science: chemical) An adrenergic neuron-blocking drug similar in effects to guanethidine. It is also noteworthy in being a substrate for a polymorphic cytochrome p-450 enzyme. Persons with certain isoforms of this enzyme are unable to properly metabolise this and many other clinically important drugs. They are commonly referred to as having a debrisoquin 4-hydroxylase polymorphism.
chemical name: 2(1H)-Isoquinolinecarboximidamide, 3,4-dihydro-