Methylphenidate

# Methylphenidate ## Overview - **Classification**: Central Nervous System (CNS) stimulant, Schedule II controlled substance. - **Mechanism**: Blocks norepinephrine and dopamine reuptake into presynaptic neurons, increasing neurotransmitter levels in the synaptic cleft. ## Primary Indications 1. **Attention-Deficit/Hyperactivity Disorder (ADHD)** - Management of inattention, hyperactivity, and impulsivity. 2. **Narcolepsy** - Treatment of excessive daytime sleepiness. ## Adult Dosing ### Standard Dosing **Attention-Deficit/Hyperactivity Disorder (ADHD)** - **IR (Immediate-Release) Tablets**: - **Dose**: Start **5 mg** once or twice daily. - **Frequency**: Increase weekly by **5-10 mg** to max **60 mg/day** in 2-3 divided doses. - **Route**: Oral. - **ER/LA (Extended/Long-Acting) Formulations**: - **Dose**: Start **10-20 mg** once daily. - **Frequency**: Adjust weekly by **10-20 mg** to max **60 mg/day**. - **Route**: Oral. - **Special Consideration**: Take in the morning; formulations vary in release profile. **Narcolepsy** - **Dose**: Start **10 mg** twice daily. - **Frequency**: Adjust weekly by **10 mg** to max **60 mg/day** in 2-3 divided doses. - **Route**: Oral. ### Dose Adjustments - **Renal Impairment**: No specific guidelines; use with caution. Primarily metabolized in the liver. - **Hepatic Impairment**: No specific guidelines; use with caution. Metabolized by de-esterification. - **Elderly Patients**: Start with lower doses; titrate slowly due to potential increased sensitivity. Avoid in severe cardiac conditions. ## Pediatric Dosing ### Neonates (0-28 days) - **Methylphenidate is NOT indicated for use in neonates.** - **Special Notes**: Safety and efficacy not established. ### Infants (1-12 months) - **Methylphenidate is NOT indicated for use in infants.** - **Special Notes**: Safety and efficacy not established. ### Children (6-12 years) **Attention-Deficit/Hyperactivity Disorder (ADHD)** - **IR (Immediate-Release) Tablets**: - **Dose**: Start **5 mg** once or twice daily. - **Frequency**: Increase weekly by **5-10 mg**. - **Route**: Oral. - **Maximum**: **60 mg/day**. - **ER/LA (Extended/Long-Acting) Formulations**: - **Dose**: Start **10-20 mg** once daily. - **Frequency**: Adjust weekly by **10-20 mg**. - **Route**: Oral. - **Maximum**: **60 mg/day**. - **Special Notes**: Consider chewable/liquid formulations for appropriate ages. ### Adolescents (13-18 years) **Attention-Deficit/Hyperactivity Disorder (ADHD)** - **Dose**: Follow adult dosing principles, starting with lower doses. - **Frequency**: Titrate gradually based on response and tolerability. - **Maximum**: **60 mg/day**. - **Special Notes**: Closely monitor growth and weight. ## Safety Information ### Contraindications - **Absolute**: Hypersensitivity to methylphenidate or product components. - **Absolute**: Glaucoma, marked anxiety, tension, or agitation. - **Absolute**: Motor tics, Tourette's syndrome, or family history of Tourette's. - **Absolute**: During or within **14 days** of MAOI administration. - **Absolute**: Severe hypertension, advanced arteriosclerosis, symptomatic cardiovascular disease. - **Relative**: History of psychosis, bipolar disorder, or substance abuse. ### Common Adverse Effects - **Very Common (>10%)**: Insomnia, headache, decreased appetite, nervousness. - **Common (1-10%)**: Tachycardia, palpitations, abdominal pain, nausea, weight loss. - **Serious but Rare**: Sudden cardiac death, stroke, psychotic episodes, seizures, severe allergic reactions, priapism. ### Key Drug Interactions - **MAOIs**: Risk of hypertensive crisis; avoid concomitant use. - **Vasopressors/Dopaminergic drugs**: Potentiates pressor effects; monitor BP closely. - **Anticoagulants (e.g., warfarin)**: May inhibit metabolism; monitor INR. - **Anticonvulsants (e.g., phenobarbital, phenytoin)**: May inhibit metabolism; monitor drug levels. - **Antihypertensives**: May counteract effects; monitor BP. ## Monitoring & Follow-up - **Before Treatment**: Baseline ECG (if cardiac risk factors), BP, HR, weight, height, psychiatric history. - **During Treatment**: BP, HR, weight/height (especially in children) at each visit. Monitor for tics or psychiatric symptoms. - **Clinical Signs**: Watch for signs of cardiovascular issues (chest pain, syncope), psychiatric changes (new or worsening agitation, psychosis), growth suppression. ## Clinical Pearls - 💡 **Tip 1**: Administer last dose of IR formulations before **6 PM** to minimize insomnia. - 💡 **Tip 2**: ER/LA formulations are usually taken once daily in the morning, with or without food. - 💡 **Tip 3**: Counsel patients/caregivers on potential for appetite suppression and importance of consistent food intake. - 💡 **Tip 4**: Avoid abrupt discontinuation of high doses, as it may cause withdrawal symptoms like depression. - 💡 **Tip 5**: Store securely due to potential for diversion and abuse. > **⚠️ Important**: This information is for educational purposes only. Always consult current prescribing information, local guidelines, and clinical judgment before prescribing.