METHYLIN
Clinical safety rating: caution
Comprehensive clinical and safety monograph for METHYLIN (METHYLIN).
Methylphenidate is a central nervous system stimulant. It blocks the reuptake of dopamine and norepinephrine into presynaptic neurons, increasing their concentrations in the synaptic cleft.
| Metabolism | Hepatic via carboxylesterase CES1A1 to ritalinic acid (major inactive metabolite). Minor pathways: hydroxylation and glucuronidation. |
| Excretion | Renal: 90% (mainly as metabolites, 30-50% as unchanged drug); fecal: <1% |
| Half-life | 2-4 hours (short elimination half-life, requiring multiple daily dosing; immediate-release: 3-4 hours, extended-release: 3-6 hours) |
| Protein binding | 10-33% (bound to albumin; low binding reduces drug interactions) |
| Volume of Distribution | 3.1-4.4 L/kg (large Vd indicating extensive tissue distribution; higher in children than adults) |
| Bioavailability | Oral immediate-release: 30-60% (±11%); extended-release: 58-72% (with food decreases rate but not extent); transdermal: 40-60% (delayed onset) |
| Onset of Action | Oral immediate-release: 30-60 minutes; oral extended-release: 1-2 hours; transdermal: 2-3 hours; intravenous: 1-5 minutes |
| Duration of Action | Oral immediate-release: 3-5 hours; oral extended-release: 8-12 hours; transdermal: 12 hours; intravenous: 1-2 hours |
| Molecular Weight | 269.3 |
10 mg orally twice daily, administered 4-6 hours apart; doses may be adjusted in 5-10 mg increments weekly up to 60 mg/day.
| Dosage form | TABLET, CHEWABLE |
| Renal impairment | No specific adjustment required; methylphenidate is minimally renally excreted. Use with caution in severe renal impairment (eGFR <30 mL/min). |
| Liver impairment | No specific adjustment recommended; use with caution in severe hepatic impairment (Child-Pugh class C). |
| Pediatric use | Initial 5 mg orally twice daily (ages 6-17); increase by 5 mg weekly; maximum 60 mg/day. |
| Geriatric use | Start at 5 mg orally once daily; titrate slowly due to increased sensitivity to adverse effects. |
| 1st trimester | Limited human data; potential for teratogenicity (cardiac malformations) based on animal studies. Use only if benefit outweighs risk. |
| 2nd trimester | Monitor fetal growth and maternal blood pressure; may cause vasoconstriction and reduced placental perfusion. |
| 3rd trimester | Risk of neonatal adverse effects (tachycardia, irritability, low birth weight). Avoid use near term. |
Clinical note
Comprehensive clinical and safety monograph for METHYLIN (METHYLIN).
| Placental transfer | Crosses placenta; fetal serum levels approximately 50-100% of maternal levels. |
| Breastfeeding | Excreted into breast milk in small amounts; potential for infant irritability and poor weight gain. Consider alternative agents or temporary discontinuation. |
■ FDA Black Box Warning
METHYLIN has a high potential for abuse and dependence. Prolonged use may lead to drug dependence. Misuse may cause sudden death or serious cardiovascular adverse events.
| Serious Effects |
Hypersensitivity to methylphenidate or any componentConcurrent use or within 14 days of MAO inhibitorsGlaucomaSymptomatic cardiovascular diseaseModerate to severe hypertensionHyperthyroidismHistory of drug abuse
| Precautions | Serious cardiovascular events including sudden death in patients with pre-existing structural cardiac abnormalities, Blood pressure and heart rate increases; monitor regularly, Psychiatric adverse events (e.g., exacerbation of pre-existing psychosis, mania, aggression), Long-term suppression of growth in children, Seizures: may lower seizure threshold, Peripheral vasculopathy including Raynaud's phenomenon |
| Food/Dietary | Take METHYLIN with or without food, but avoid high-fat meals as they may delay absorption and reduce peak concentration. Avoid acidic foods or beverages (e.g., citrus juices, cola) within 1 hour of dosing as they may affect drug release. Caffeine intake should be minimized as it may exacerbate central nervous system stimulation. |
Loading safety data…
| Lactation Rating |
| L3 (Moderately Safe) |
| Teratogenic Risk | Pregnancy Category C. There are no adequate and well-controlled studies in pregnant women. In animal studies, methylphenidate has been shown to cause developmental toxicity at doses higher than clinical doses. Use during pregnancy only if potential benefit justifies potential risk to the fetus. First trimester: potential risk of congenital malformations; second and third trimesters: risk of decreased fetal growth and neonatal neurobehavioral effects. |
| Fetal Monitoring | Monitor maternal blood pressure, heart rate, and weight. Assess for symptoms of stimulant abuse or dependence. Fetal monitoring includes ultrasound to monitor fetal growth and development. Neonatal monitoring for signs of withdrawal or adverse effects such as irritability, feeding difficulties, and growth parameters. |
| Fertility Effects | In animal studies, methylphenidate did not impair fertility at clinically relevant doses. Human data are insufficient to determine effects on fertility. May cause menstrual irregularities or decreased libido in some individuals. |
| Clinical Pearls | METHYLIN is a methylphenidate formulation intended for once-daily oral administration. The capsule should be swallowed whole and not crushed, chewed, or split due to its extended-release mechanism. Peak plasma concentrations occur at approximately 5 hours. Monitor for hypertension, tachycardia, and psychiatric adverse effects (e.g., psychosis, mania). Avoid use within 14 days of MAO inhibitors. Growth suppression may occur; monitor height and weight in pediatric patients. Abuse potential is high; assess for history of substance use disorder. |
| Patient Advice | Take METHYLIN exactly as prescribed, once daily in the morning. Swallow the capsule whole; do not crush, chew, or split it. · Do not take any over-the-counter medications, especially those containing decongestants or cold remedies, without consulting your doctor. · Avoid alcohol consumption while taking METHYLIN; it can increase the risk of adverse effects. · Report any signs of heart problems such as chest pain, shortness of breath, or fainting, and any psychiatric symptoms like new or worsening aggression, hallucinations, or mania. · This medication may cause dizziness or blurred vision; do not drive or operate machinery until you know how it affects you. · Store METHYLIN at room temperature, away from moisture and heat, and keep out of reach of children. · Do not stop METHYLIN suddenly without consulting your doctor; abrupt discontinuation can cause withdrawal symptoms. |