Papaverine rapidly increases heart rate and blood pressure, thus increasing blood flow to the penis, resulting in erection amongst men with erectile disorder.

Papaverine is a vasodilator that works by relaxing the muscles in blood vessels to increase blood flow, but it does not rapidly increase heart rate and blood pressure. It is used in the treatment of erectile dysfunction by directly injecting it into the penis to help achieve an erection, not by increasing heart rate and blood pressure.