Pharmacodynamics of intracavernously injected drugs and cavernous wall resistance

It was our aim to investigate whether drug transfer from the cavernous bodies to the systemic circulation after intracavernous (i.c.) injection is influenced by the resistance of the cavernous wall.

i.c. injection of 62.5 micrograms digoxin as a tracer. (1) In 32 volunteers; in 5 together with the vasocontractor norepinephrine, in 20 together with a 'trimix' of vasodilators, in 7 alone without vasoactive drug. Plasma digoxin levels were measured after 5, 10 and 15 min. (2) Together with a trimix of vasodilators, in 30 men presenting a normal cavernosometry and in 30 men presenting an abnormal one. Plasma digoxin levels were measured after 2, 3, 5, 6, 10 and 15 min.

(1) One minute after i.c. injection, the plasma peak of digoxin was 40 times higher (p < 0.01) after injection with norepinephrine than after injection with vasodilators. (2) There was a statistically significantly (p < 0.01) higher plasma digoxin level 5, 6, 10 and 15 min after injection in the 30 patients presenting an abnormal cavernosometry than in the 30 patients presenting a normal one.

Drug transfer from the cavernous bodies to the systemic circulation is highly influenced by the resistance of the cavernous wall. It seems possible to diagnose cavernous leakage by means of a peripheral dosage of a routinely dosable drug, injected i.c. together with vasodilators.