Investigation of the Effects of Methylphenidate on Hemodynamic Parameters in Children With ADHD.

This prospective observational study investigated the acute effects of a single 10 mg dose of methylphenidate (MPH) on hemodynamic and electrocardiographic parameters in 60 children aged 6-16 years newly diagnosed with Attention Deficit Hyperactivity Disorder (ADHD). All participants received 10 mg short-acting MPH, and systolic and diastolic blood pressure, heart rate, and electrocardiographic measurements (QTc, PR, QRS intervals, and rhythm) were obtained both before and 30-45 min after administration under standardized conditions and interpreted by a pediatric cardiologist. Following MPH intake, significant increases were observed in systolic blood pressure (105.0 ± 7.7 to 110.1 ± 8.9 mmHg, p < 0.001), diastolic blood pressure (69.3 ± 9.2 to 73.4 ± 9.8 mmHg, p < 0.001), and heart rate (79.8 ± 9.0 to 84.9 ± 9.8 bpm, p < 0.001). QTc (395.9 ± 11.6 to 401.0 ± 12.5 ms), PR (135.8 ± 16.8 to 140.9 ± 16.7 ms), and QRS durations (91.1 ± 9.5 to 93.6 ± 9.5 ms) also showed significant prolongation (all p < 0.001). Post-treatment ECG rhythm abnormalities were observed in 15.0% of participants (p = 0.002), including sinus tachycardia, sinus arrhythmia, and isolated premature atrial or ventricular beats, with markedly higher prevalence among those below the 5th BMI percentile (75.0%, p < 0.001), whereas no rhythm disturbances were detected in the 5th-85th percentile group. These findings indicate that MPH induces acute but measurable cardiovascular changes in children with ADHD, particularly in underweight children, underscoring the need for ECG and blood pressure monitoring during treatment initiation.