Selective alpha adrenergic antagonist reduces severity of transient hypertension during sexual stimulation after spinal cord injury.

Abstract

On a daily basis, the majority of those with high-level spinal cord injury have autonomic dysreflexia, which describes a life-threatening episode of transient extreme hypertension (i.e., as high as 300 mm Hg) as many as 90% of people living with this condition. Unfortunately, ejaculation is a major initiating factor for autonomic dysreflexia, which discourages sexual activity. In order to obtain a sperm specimen, or for initial assessment of fertility, penile vibrostimulation is clinically performed. Nifedipine, a selective calcium channel blocker, is the most commonly prescribed pharmaceutical for a priori management of autonomic dysreflexia secondary to ejaculation or other causes; however, it is limited because of its potential exacerbation of low resting pressure, which also affects this population. The present study examined the effect of a short-acting selective α1 antagonist (prazosin) on autonomic dysreflexia severity using a randomized placebo trial during medically supervised penile vibrostimulation in six males with cervical spinal cord injury. Beat-by-beat blood pressure and heart rate were recorded throughout penile vibrostimulation during placebo and prazosin-treated days. The increase in systolic blood pressure was mitigated during vibrostimulation in subjects administered prazosin as compared with those administered placebo (+140±19 mm Hg vs. +96±14 mmHg; p<0.05). On average, the peak in systolic blood pressure was 46 mm Hg lower during penile vibrostimulation when patients were administered prazosin (p<0.05), whereas resting blood pressure was not affected. Prazosin appears to be effective at reducing the severity of autonomic dysreflexia during sexual stimulation in patients with spinal cord injury, without exacerbating resting hypotension in high-level spinal cord injury.