Phentolamine given by injection causes blood vessels to expand, thereby increasing blood flow. When injected into the penis (intracavernosal), it increases blood flow to the penis, which results in an erection.
phentolamine should not be used as a sexual aid by men who do not have erectile dysfunction. If the medicine is not used properly, permanent damage to the penis and loss of the ability to have erections could result.
Phentolamine may also be used to reverse the effects of an anesthetic medicine in soft tissues, such as the lips and tongue. It may be used to help quickly restore normal sensation and function in patients who have received local dental anesthesia .
erection continuing for more than 4 hours, or painful erection
lumps in the penis
Some phentolamine side effects may not need any medical attention. As your body gets used to the medicine these side effects may disappear. Your health care professional may be able to help you prevent or reduce these side effects, but do check with them if any of the following side effects continue, or if you are concerned about them:
Less common or rare
Bruising or bleeding at place of injection
burning (mild) along penis
difficulty in ejaculating
swelling at place of injection