The erection may last for a while even after ejaculation and become completely soft only when the medicine wears off. In rare cases, the erection may stay firm for more than 3 hours, which results in a medical emergency. The man must then go to the emergency room, where a physician may need to inject other medication into the penis to reverse the erection. In our own program, only 1 of more than 500 patients has had to have such emergency treatment. When conservative doses of medication are used and men follow instructions carefully, the risk of prolonged erection is quite small.
Men are often uncomfortable at first with the thought of injecting their penis.
Many men are able to come to terms with the idea after having a diagnostic test injection as part of their evaluation, however. Others feel comfortable with the injection from the outset. They see this treatment as giving them the closest response to a natural erection. Some men have their partners learn to do the injection. A few men never achieve good erections with injection therapy, but most are successful after some adjustment of dose or type of medication.