Phenylephrine (priapism rescue)
Sexual Well-Being
In plain English
Phenylephrine is a blood-vessel-tightening medicine used as a rescue treatment for a prolonged, painful erection (priapism), which can happen with penile injection therapy. Injected into the penis (by or under guidance of a clinician), it helps the erection go down and protects the tissue from damage. A prolonged erection is a medical emergency that needs prompt treatment.
The science
Phenylephrine is a selective alpha-1 adrenergic agonist that causes cavernosal smooth-muscle contraction and vasoconstriction, reducing arterial inflow to reverse ischemic (low-flow) priapism. It is the guideline-preferred intracavernosal sympathomimetic for acute ischemic priapism and for prolonged erections following intracavernosal vasoactive therapy because of its relative alpha-1 selectivity and minimal beta activity, given as diluted aliquots with blood-pressure and heart-rate monitoring (AUA/SMSNA guidance). Systemic absorption can cause hypertension, reflex bradycardia, and headache—monitoring is required, with particular caution in cardiovascular disease. Ischemic priapism lasting beyond ~4 hours is an emergency requiring aspiration/irrigation and phenylephrine to prevent cavernosal fibrosis and permanent erectile dysfunction. Use is a recognized medical intervention rather than a self-administered therapy.