A comparison of the efficacy of an alpha-I-adrenergic blocker in the slow calcium channel blocker in the control of autonomic dysreflexia.

Cystometry, using a portable CO2 cystometer, is a convenient method for detecting autonomic dysreflexia (A.D.) in response to bladder distention. Serial tracings on successive days were found to be consistent. This method was used to compare the effect of the antihypertensive drugs, phenoxybenzamine and nifedipine, in modifying the blood pressure responses of 12 tetraplegic patients. Given as regular medication twice daily, neither drug was effective in preventing A.D. responses to bladder filling, and a significant number of patients developed troublesome hypotension. Nifedipine by mouth was found to be a valuable drug for the treatment of attacks which developed, and capable of preventing an anticipated attack if given shortly before the stimulus. The condition of 'status dysreflexicus' and its appropriate management is described.