Common ADHD drug confers benefits for lower urinary tract in children

Use of the prescription stimulant methylphenidate appears to also exert a positive effect on the lower urinary tract in children with attention deficit hyperactivity disorder (ADHD) but without voiding dysfunction, specifically increasing voided volume and bladder capacity, as shown in a study.

The study included 43 children (mean age, 11.84 years; 70.9 percent boys) with ADHD but without voiding dysfunction and 39 healthy participants (mean age, 11.24 years; 71.8 percent boys). All patients in the ADHD group were given the stimulant following baseline screening.

Researchers evaluated lower urinary tract symptoms (LUTS) and quality of life, in addition to uroflowmetry test results and postvoiding residual volume (PVRV), in both groups at baseline and 4 weeks later. They used the dysfunctional voiding scoring system questionnaire to score LUTS, and ultrasound to measure postvoiding residual volume.

Results showed that at week 4, methylphenidate treatment resulted in significant increases from baseline in voided volume (p=0.001) and bladder capacity (p=0.002). These improvements were not observed in the control group.

While unclear, the mechanism underlying the favourable effect of the stimulant on voided volume and bladder capacity may be attributed to the dopaminergic and noradrenergic effects of the drug, according to the researchers. However, they acknowledged that medication with methylphenidate may not necessarily produce clinically significant improvements in LUTS in ADHD patients diagnosed with voiding dysfunction.

More studies are needed to evaluate the effects of the drug on LUTS in a urodynamic study in ADHD patients with voiding dysfunction to enhance the reliability of the present data.