dexmethylphenidate

Dexmethylphenidate is a centrally acting stimulant medication used to treat attention-deficit/hyperactivity disorder (ADHD) and, in some cases, narcolepsy. It is the dextrorotatory enantiomer of methylphenidate, the active component in the racemic mixture. Dexmethylphenidate is marketed in immediate-release and extended-release forms, commonly under the brand names Focalin and Focalin XR. It is a Schedule II controlled substance in the United States due to potential for abuse and dependence.

Pharmacology and administration: Dexmethylphenidate increases extracellular dopamine and norepinephrine in the brain by inhibiting their transporters, which enhances attention and reduces impulsivity and hyperactivity. It is taken orally, with the immediate-release form typically providing several hours of effect and the extended-release form delivering a longer duration, often throughout the day. Metabolism occurs in the liver to ritalinic acid, and the drug is primarily excreted in urine. Typical half-life is in the range of a few hours, with extended-release formulations designed to maintain coverage for a full day.

Indications and dosing considerations: Dexmethylphenidate is approved for ADHD in children and adults and may be used for narcolepsy in some cases. Dosing is formulation- and patient-specific and generally starts at a low level with gradual titration while monitoring efficacy and adverse effects. Clinicians may adjust dosing based on response and tolerability.

Contraindications and precautions: It should not be used in individuals with known hypersensitivity to stimulants, with concomitant monoamine oxidase inhibitors, or in those with significant anxiety, agitation, glaucoma, or severe cardiovascular disease. Caution is advised in patients with a history of tics or Tourette syndrome and in those with a history of substance use disorder. Abuse potential and cardiovascular effects require ongoing monitoring.