A 42 year-old man turns up in the emergency room and presents his erection of 22-hour duration. The erection is very painful. It occurred spontaneously, the patient says. Sexual stimulation did not occur; he also denies taking sexual performance-enhancing drugs.
No relief in sight
Already one hour after his erection began, the man felt pain. The symptoms had not yet subsided – in spite of numerous attempts to self-treat using cold packs. The doctors continue to investigate a possible cause and finally the man reports that the erection occurred shortly after a subcutaneous injection of melanotan.
Melanotan II is a synthetic substance that the patient acquired as a tanning agent in a bodybuilding shop. It achieves similar effects to those of the naturally occurring hormone α-MSH which stimulates the melanocytes of the skin. He had noticed prolonged erections after previous injections of melanotan, the patient says, but these had always regressed after one to two hours.
One goes for the needle
After a further cooling attempt on the part of the medical staff has no effect, the man receives a penis block as regional anesthesia. Following this, a bilateral aspiration of about 700 ml of blood from both corpora cavernosa was performed.
The blood lactate level is 7.1 mg/dL, confirming both the suspected diagnosis of low-flow priapism and the presence of penile ischaemia. The patient receives treatment in the form of an injection of 200 μg phenylephrine every five minutes.
After the fifth injection, this treatment finally achieves its effect and the erection subsides. The result of the subsequent blood gas analysis already shows normal levels and so the patient can be released shortly afterwards.
So far, only a few cases of melanotan-induced priapism are known. Nevertheless, in the bodybuilding scene better education on the dangers of regular melanotan application should be sought, the doctors state in their report. They also suggest that, in the case of a melanotan-induced enduring erection, treatment with phenylephrine should always be undertaken prior to surgical intervention.
Source Text: Dreyer et al / BMJ Case Reports
Image Source: Bob Paris / Wikimedia commons