What do I do if I have a persistent erection?
Priapism is a persistent erection, usually painful, that is not necessarily associated with stimulation or sexual desire. Much debate has taken place as to the meaning of “persistent erection”, but the current view is that the erection needs to be present for six hours. In practice, the usual recommendation is to seek medical help for a painful erection persisting for more than four hours.
A normal erection results from relaxation of the muscles within the penis and an increase in arterial blood flow to the penis. The resulting swelling of the muscles compresses the penile veins, thus trapping blood within the penis. After ejaculation, the associated adrenaline surge constricts the arteries and relaxes the pressure on the veins, which leads to loss of erection (detumescence).
Priapism may be spontaneous or caused by medical treatment (iatrogenic). Some cases are idiopathic (unknown cause) and some are associated with drug therapy or alcohol abuse. Trauma and blood disorders account for some. Medically, the important issue is whether the condition is associated with high blood flow when there is little risk of tissue damage, or low blood flow when the risk of damage is higher.
In very rare cases, unresolved priapism can lead to severe damage to the tissues of the penis. If this occurs, erections can be affected. In this case, an implant or prosthesis can be surgically placed within the penis.
Although controversy exists over the way in which priapism occurs, a widely accepted view is that priapism results from injury or damage to the mechanism that produces detumescence of the penis. This damage can be caused by:
- Blood disorders, particularly sickle cell disease, myeloma, thalassaemia and leukaemia.
- Trauma, both accidental and surgical.
- Damage to the nervous system, especially spinal cord injuries, but rarely multiple sclerosis or diabetes (this usually involves an element of overstimulation, resulting in high blood flow to the penis, as well as defective detumescence).
- Drugs used to treat impotence (particularly those given by injection into the penis):
- prostaglandin E1, which causes increased blood flow by dilating blood vessels in the penis (very rare if given into the urethra or urine tube in the penis)
- sildenafil (Viagra) virtually unknown unless combined with other medication e.g. injections such as prostaglandin
- Other drugs, especially in overdose:
- psychiatric drugs: trazodone and chlorpromazine
- blood pressure drugs: prazosin and nifedipine
- anticoagulants: warfarin and heparin
- miscellaneous: omeprazole, metoclopramide, and tamoxifen
How is priapism treated?
The presence of a painful erection for longer than four hours justifies a medical assessment by a doctor or hospital if this is quicker. Many cases resolve spontaneously after repeated ejaculation, physical activity or a brisk walk. Oral terbutaline or salbutamol may help if given early. Blood (50ml) can be removed by a doctor inserting a needle into the penis often in conjunction with heparin and saline to reduce clotting. In resistant cases, a reversing agent, metaraminol may be injected into the penis. In very rare cases, surgery is required to avoid permanent damage to the muscle of the penis. In cases in which priapism is related to an injection used to treat impotence, alternative therapy should be used in future. Luckily, with the development of oral drugs, cases of priapism due to impotence treatments are becoming increasingly rare.