Acute dose-related differential effects of methylphenidate on murine cystometric parameters.
OBJECTIVE
Methylphenidate is the most widely used central nervous system stimulant in patients with attention deficit hyperactivity disorder. However, few studies have assessed its effects on voiding. Various doses of methylphenidate were investigated for their effects on cystometric parameters in conscious mice.


METHODS
Ten male C57BL/6 mice, weighing between 20 and 23 g, were used in this study. To compare the acute drug responses before and after the oral medication was administered in the awake condition, we injected the solution through a catheter inserted into the stomach. Methylphenidate (1.25, 2.5, and 5 mg/kg) in an injection volume of 0.05 mL was administered.


RESULTS
Four mice that received high doses of methylphenidate (2.5 and 5 mg/kg) showed no voiding contraction, with urine leakage. Six mice that received a low dose of methylphenidate (1.25 mg/kg) showed typical micturition cycles before and after administration. The micturition pressure decreased and bladder capacity increased without an increased residual volume after administration.


CONCLUSIONS
Methylphenidate has differential, dose-dependent effects on the function of the lower urinary tract, due to the dependent relationship between the brain and lower urinary tract. Especially at higher doses, this drug may interfere with normal micturition. Therefore, more detailed clinical or experimental studies are warranted in the future.
Department of Urology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea.
Sung Ho
SH
Choi
Department of Urology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea.
Young Sam
YS
Cho
Department of Urology, Hallym University Kangnam Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Korea.
Sung Tae
ST
Cho
Department of Urology, Inha University Hospital, Inha University School of Medicine, Incheon, Korea.
Tack
T
Lee
Department of Urology, Gachon University Gil Medical Center, Gachon University Medicine and Science, Incheon, Korea.
Khae Hawn
KH
Kim
Attention deficit disorder with hyperactivity; Methylphenidate; Mice; Neurogenic urinary bladder; Urodynamics