Also Known As: Phenoxybenzamine, Dibenzyline
Phenoxybenzamine (marketed under the trade name Dibenzyline) is a non-selective, irreversible alpha antagonist.
It is used in the treatment of hypertension, and specifically that caused by pheochromocytoma. It has a slower onset and a longer lasting effect compared with other alpha blockers.
It was also the first alpha blocker to be used for treatment of benign prostatic hyperplasia, although it is currently seldom used for that indication due to unfavourable side effects.
It has been used in the treatment of hypoplastic left heart syndrome.
It is also used in Complex Regional Pain Syndrome Type 1 due to its anti-adrenergic affects. It has shown to be beneficial if used in the first 3 months of CRPS diagnosis.
Phenoxybenzamine has long been known to block ejaculation without affecting semen quality or ability to achieve orgasm, which could make it an effective male contraceptive. This effect is completely reversible, and is believed to be the result of alpha-1 adrenoceptor blockade in the longitudinal muscles of the vas deferens. As of 2008, research was underway to identify possible drug candidates that share this effect but act specifically on the reproductive tract, unlike phenoxybenzamine