Effects of bethanechol chloride on the external urethral sphincter in spinal cord injury patients.

The neuropharmacodynamics of bethanechol chloride on the external urethral sphincter in male spinal cord injury patients with chronic lesions have been investigated. There were 90 cystosphincterometric and sphincteroperineal electromyographic studies conducted on 45 subjects in 4 different positions, showing varying urodynamic patterns. A gross postural cystophincteric discordant reflex was noted in the majority of patients with recent complete upper motor neuron bladders (less than 2 years in duration). The external sphincter tends to be coordinated in late cases of quadriplegics and in all paraplegics. With the administration of bethanechol chloride there was an increase in the striated sphincter pressure profile when the patient was in the sitting position, resulting in detrusor sphincter dyssnergia. This phenomenon seems to be dose-related. When the dose of bethanechol chloride is adjusted according to the types of vesicourethral dysfunctions or in combination with dantrolene sodium the most beneficial non-surgical rehabilitation of the urinary tract can be obtained in this particular group of patients.