Urinary hesitancy with therapeutic doses of L-tryptophan

L-tryptophan, a precursor of serotonin, in doses of 4 to 5 g/d, has been found to be effective in increasing sleep time, reducing sleep latency, and reducing the number of awakenings. In this report, L-tryptophan 4-6 g/d was administered, along with niacinamide 100 mg and pyridoxine 50 mg, for sleep. Two days after starting L-tryptophan, the patient reported difficulty in voiding. Medications with known anticholinergic activity were selectively discontinued during the patient's hospital course. Seven days after the last dose of L-tryptophan, improvement was noted in the patient's urinary status. Prior to discharge, doxepin was restarted and titrated up to 150 mg/d without a recurrence of urinary problems.