Which agents are used for penile pharmacologic induction during testing?

• A. Aspirin, Heparin
• B. Epinephrine, norepinephrine
• C. Saline solution
• D. Papaverine, Prostaglandin

Answer: (D)

The idea is to use a medication injected into the penis to provoke an erection so you can assess penile blood flow on ultrasound. The standard agents are papaverine and prostaglandin E1 because they induce erection by relaxing the smooth muscle of the corpora cavernosa, increasing arterial inflow and producing a measurable erection suitable for Doppler testing.

Papaverine works by inhibiting phosphodiesterases, which raises smooth muscle relaxants like cAMP and cGMP, leading to vasodilation. Prostaglandin E1 acts by increasing cAMP in cavernosal smooth muscle, also causing potent vasodilation and enhanced arterial inflow. Together, they create the necessary hemodynamic conditions to evaluate the vascular components of erectile function.

The other options won’t achieve this effect: anticoagulants don’t induce erection, vasoconstrictors would impair flow, and saline wouldn’t produce a usable erection.