Urinary urgency following administration of thyrotropin releasing hormone during simultaneous urethrocystometry

To study the pathophysiology of urinary urgency frequently reported on administration of thyrotropin releasing hormone (TRH), simultaneous urethrocystometry was performed in 10 women before and after administration of 500 micrograms of TRH. Nine women in the control group received normal saline in place of TRH. The TRH group demonstrated a significant drop in urethral closure pressure (p less than 0.01) within two minutes after TRH injection. Eight women complained of urinary urgency during the interval of observed drop in urethral closure pressure. No significant changes were seen in true detrusor pressure in both the TRH and in the control groups. The close association of drop in urethral pressure and urinary urgency suggests the presence of a motor component to this either centrally or peripherally mediated urinary urgency following TRH administration.