Objective: To probe into the effects of methylphenidate hydrochloride controlled-release tablets on the cardiovascular system of children with attention deficit hyperactivity disorder (ADHD). Methods: Retrospective analysis was performed on clinical data of 98 children with ADHD. All children were treated with methylphenidate hydrochloride controlled-release tablets at an initial dose of 18 mg/d

which was adjusted to 36 mg/d after 2 weeks

if the clinical relief was unsatisfactory. After being evaluated by the SNAP-Ⅳ scale

parents were able to adhere to the treatment

and one observation period of 3 months of medication was used. Changes of safety indexes of cardiovascular system were observed before and after treatment. Results: Compared with before treatment

children’s heart rate increased after treatment (P<0.05)

and there was no significant change in systolic blood pressure and diastolic blood pressure (P>0.05); the heart rate variability and heart deceleration decreased after treatment (P<0.05)

but both were within the normal range. There was no statistically significant difference in the incidence of adverse drug reactions and cardiovascular indexes among people with different medication doses (P>0.05). Conclusion: Treatment of methylphenidate hydrochloride controlled-release tablets for children with ADHD has less effects on the cardiovascular system

yet the effect of long-term administration needs to be confirmed by further studies.