Experimental study on the action of diltiazem on detrusor muscle and clinical evaluation in patients with detrusor hyperactivity.

Diltiazem added to the medium before administration of the agonist, caused a concentration-dependent antagonism of potassium chloride-induced contractions in strips of rat detrusor and human detrusor. When added at the time of peak potassium chloride-induced increase in muscle tone, the drug lowered the tone gradually and concentration-dependently. Diltiazem also depressed carbachol-induced contractions. In patients with disturbances of micturition due to detrusor hyperactivity, oral diltiazem (Angizem) treatment for 10 days significantly increased bladder capacity, lowered bladder pressure and maximum detrusor pressure and raised the threshold of the second sensation of micturition. In addition, diltiazem significantly reduced frequency of diurnal and nocturnal micturition and number of episodes of incontinence. Diltiazem appears to be an effective detrusor muscle relaxant and may be useful for the treatment of disturbances of micturition due to detrusor hyperactivity.