Methylphenidate is a central nervous system (CNS) stimulant of the phenethylamine and piperidine classes. It is a first-line pharmacological agent for the treatment of Attention Deficit Hyperactivity Disorder (ADHD) and is also indicated for narcolepsy. It primarily acts as a norepinephrine-dopamine reuptake inhibitor (NDRI), increasing the levels of these neurotransmitters in the synaptic cleft, thereby improving attention, focus, and impulse control. The 5mg strength is typically used for initial dose titration, especially in pediatric patients, and for managing patients who are sensitive to stimulant effects.
Adult: ADHD: Start with 5mg once or twice daily (e.g., morning and noon). Titrate gradually in increments of 5-10 mg per week based on response and tolerability. Usual effective dose range: 20-30 mg/day in 2-3 divided doses. Maximum: 60 mg/day. Narcolepsy: 20-30 mg/day in divided doses.
Note: Administer orally, with or without food (taking with food may delay absorption). Tablet can be split for dose titration. Administer the first dose on awakening, subsequent doses at 4-6 hour intervals. Avoid late afternoon or evening doses to prevent insomnia. Do not crush or chew extended-release formulations (not applicable to 5mg IR).
Methylphenidate is a psychostimulant that blocks the presynaptic norepinephrine and dopamine transporters (NET and DAT). This blockade inhibits the reuptake of norepinephrine and dopamine into the presynaptic neuron, increasing the concentration of these neurotransmitters in the synaptic cleft, particularly in the prefrontal cortex and striatum. The increased dopaminergic and noradrenergic activity in these brain regions is responsible for improving attention, executive function, and behavioral inhibition.
Pregnancy: Pregnancy Category C (US FDA). Animal studies have shown adverse effects. There are no adequate and well-controlled studies in pregnant women. Use only if the potential benefit justifies the potential risk to the fetus. Neonates born to mothers taking methylphenidate may experience withdrawal symptoms.
Driving: May impair ability to drive or operate machinery, especially during initial treatment or dose adjustment. Patients should be cautioned until they are sure the medication does not affect them adversely.
| Monoamine Oxidase Inhibitors (MAOIs) - e.g., Phenelzine, Selegiline, Moclobemide | Risk of hypertensive crisis, hyperpyrexia, serotonin syndrome. | Contraindicated |
| Anticoagulants (Warfarin) | Methylphenidate may inhibit metabolism of warfarin, increasing INR and bleeding risk. | Major |
| Anticonvulsants (Phenobarbital, Phenytoin, Primidone) | Methylphenidate may increase levels of these drugs, increasing toxicity risk. | Moderate |
| Tricyclic Antidepressants (TCAs - e.g., Imipramine, Desipramine) | Increased levels of TCA; increased risk of cardiovascular side effects. | Moderate |
| Pressor Agents (e.g., Dopamine, Epinephrine) | Additive pressor effects; risk of severe hypertension. | Major |
| Clonidine | Case reports of serious adverse events (hypertension, ECG changes); combination should be avoided or used with extreme caution under specialist supervision. | Major |
| Alcohol | May alter the absorption profile of methylphenidate; CNS effects may be unpredictable. | Moderate |