Methylphenidate (MPH) is a psychostimulant drug which acts by blocking the dopamine and norepinephrine
transporters and is the main drug used to treat attention deficit hyperactivity disorder in children and adolescents.
During puberty, changes in neurotransmitter systems (including dopaminergic system) are engaged on
the release of gonadal hormones and the development of cephalic structures responsible for reproductive function.
This study investigated the effects of repeated treatment with methylphenidate during development on
reproductive parameters of adult male rats. Wistar rats received MPH 2.5 mg/kg, MPH 5.0 mg/kg, or distilled
water (gavage) from postnatal day (PND) 21 to PND 60. At PND 100, an increase in percentage of abnormal
tail morphology sperm in MPH 2.5 and increase in testicular interstitial tissue volume in MPH groups as well
as in the number of type A spermatogonia in MPH 5.0 group were observed. This study demonstrated that repeated
administration of methylphenidate during periods corresponding childhood to early adulthood interfered on
testicular function in rats at adult life.