Use of dantrolene sodium in external sphincter spasm.

In various neurologic and non-neurologic diseases inappropriate hypertonicity of the external sphincter during micturition may cause outlet obstruction. Heretofore therapy for these disorders has been surgical: pudenal neurectomy or external sphincterotomy. These procedures are not without complication (incontinence, impotence, hemorrhage). A medical approach to this disorder is therefore warranted. In a selected group of patients with external sphincter spasm diagnosed by concitant sphincter electromyography, cystometrography, and voiding cystourethrography, dantrolene sodium (Dantrium) therapy was instituted. Follow-up studies have shown this drug to be effective in treating this disorder.