Methylphenidate has mild hyperglycemic and hypokalemia effects and increases leukocyte and neutrophil counts.

Various psychotropic drugs may affect the hematological and biochemical profiles of plasma and its metabolism. Carbamazepine, the most well-known psychotropic drug, can cause substantial hyponatremia. Methylphenidate, a piperidine derivative structurally related to amphetamines, acts as a central nervous system stimulant. The current study evaluated whether methylphenidate affects hematological and biochemical parameters of patients diagnosed with attention deficit hyperactivity disorder.Patients undergoing treatment for attention deficit hyperactivity disorder at our Adolescent Psychiatric Clinic were enrolled in the study. Blood samples for complete blood count and common biochemical analyses were collected before patients started methylphenidate and after 3 months of continuous treatment.Participants included 64 patients comprised the study cohort. There were 48 (75%) males and 16 (25%) females, with a median age of 16 years (range 11-31). The total median potassium level decreased by 0.6 mg/dL (P < .0001), while glucose rose by 15 mg/dL (P < .0001), sodium decreased in 0.7meq/L, (P = .006). The white blood count rose by 1350 cells/μL (P < .033) due to neutrophilia, lymphocytosis and eosinophilia. Hemoglobin rose slightly by 0.1 (P = .041). Changes in calcium, phosphorus, protein, albumin, and liver enzyme levels were not significant.The results indicate that methylphenidate may cause hypokalemia and elevated glucose, leukocyte, neutrophil, lymphocyte and eosinophil counts.