The phentolamine test in neurogenic bladder dysfunction.

In an attempt to improve the selection of patients with neurogenic bladder dysfunction likely to benefit from phenoxybenzamine therapy, the effect of intravenous phentolamine (Regitine) on the urinary flow rate was determined in normal and abnormal subjects. A nomogram relating mean flow rate to volume voided was constructed to aid in the interpretation of results. In 16 patients with neurogenic bladder dysfunction it was found that a response of more than 0.8 nomogram units indicates a likelihood of clinical improvement with phenoxybenzamine therapy. The clinical applications of this test are discussed.