methylphenidate

Methylphenidate is a central nervous system stimulant used primarily to treat attention-deficit/hyperactivity disorder (ADHD) and narcolepsy. It is a piperidine derivative that increases extracellular dopamine and norepinephrine by blocking their reuptake, an effect that enhances activity in brain regions such as the prefrontal cortex that regulate attention and impulse control. The drug is available in several formulations, including immediate-release and extended-release forms, to accommodate different dosing schedules.

Medical use and administration

For ADHD, methylphenidate is prescribed for children and adults when nonpharmacological interventions have not provided sufficient benefit. It may also be used for narcolepsy. Dosing is individualized and typically titrated to achieve symptom control while limiting adverse effects. Extended-release formulations allow once-daily administration, whereas immediate-release preparations require multiple daily doses. The choice of formulation depends on the patient’s age, symptom profile, and tolerance.

Pharmacology and pharmacokinetics

Orally administered methylphenidate is rapidly absorbed, with onset usually within 30 to 60 minutes for immediate-release products. The duration varies by formulation: roughly 3 to 4 hours for immediate-release and up to 8 to 12 hours for extended-release preparations. Methylphenidate is metabolized in the liver, producing inactive metabolites and the active metabolite ritalinic acid, and is excreted primarily in the urine.

Safety and regulation

Common adverse effects include decreased appetite, insomnia, abdominal pain, headache, and elevated blood pressure or heart rate. Growth effects with long-term use and potential for misuse or dependence are considerations. Contraindications include hypersensitivity to methylphenidate, significant anxiety or agitation, glaucoma, known structural cardiac abnormalities, and certain mood or psychotic disorders. In many countries, methylphenidate is a controlled substance with prescription and monitoring requirements. The drug was first synthesized in the mid-20th century and marketed as Ritalin before generic versions became available.