Bladder dysfunction during the use of tramadol

The Netherlands Pharmacovigilance Foundation LAREB received five case reports concerning transient impairment of micturition or urinary retention, suspected to be induced by tramadol. In all patients--three women and two men--the symptoms occurred in temporal association with the use of tramadol and promptly recovered after stopping of the drug. Tramadol was taken orally in doses within the recommended therapeutic range (150 mg or less daily). Disturbance of micturition is not mentioned as a side-effect in the summary of product characteristics of Tramal 50 and 100. Tramadol is an opioid agonist, however, and morphine is known to increase the tonus of the bladder sphincter and to cause urinary retention.