methylphenidat

Methylphenidat is a central nervous system stimulant commonly used in the treatment of attention-deficit/hyperactivity disorder (ADHD) and, in some cases, narcolepsy. In many countries the spelling methylphenidat is used in place of methylphenidate, but the substance refers to the same drug class and therapeutic use.

Pharmacology and mechanism of action. Methylphenidat increases extracellular concentrations of dopamine and norepinephrine by blocking their reuptake through the dopamine transporter (DAT) and norepinephrine transporter (NET). This leads to higher catecholamine activity in brain regions involved in attention, impulse control, and executive function, particularly the prefrontal cortex. The drug is commonly used as a racemic mixture; the dextro isomer (dexmethylphenidat) is more pharmacologically active, and separate formulations exist.

Forms and administration. Methylphenidat is available in immediate-release and extended-release formulations. Immediate-release products provide shorter, multiple daily doses, while extended-release products (such as osmotic-release or other long-acting forms) aim to maintain symptom control over most of the day. In addition to oral tablets and capsules, a transdermal patch formulation is available in some markets. Dosing and product selection are tailored to individual response and tolerability.

Safety, side effects, and cautions. Common adverse effects include reduced appetite, trouble sleeping, abdominal discomfort, headache, and increased heart rate or blood pressure. Other risks include anxiety, irritability, and potential for misuse or dependence. Caution is advised in patients with hypertension, glaucoma, a history of tics or seizures, or mood disorders; growth and weight effects are monitored in children. Use with monoamine oxidase inhibitors is contraindicated.

Regulatory status and history. Methylphenidat is a controlled substance in many jurisdictions due to potential for abuse. It has a long history as a first-line pharmacological option for ADHD and remains widely prescribed in both pediatric and adult populations.