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| {{MedTemplate
| | #REDIRECT [[Dexmethylphenidate]] |
| | generic = Dexmethylphenidate
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| | brand = Focalin, Focalin XR
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| | structure = Methylphenidate.svg
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| | classes = Psychostimulant, CNS stimulant, NDRI
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| | mechanism = Norepinephrine–dopamine reuptake inhibition (DAT, NET) — d-threo enantiomer of methylphenidate
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| | uses = ADHD
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| | formula = C<sub>14</sub>H<sub>19</sub>NO<sub>2</sub>
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| | routes = Oral
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| | onset = 30–60 min
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| | duration = IR 4–6 h; XR 8–12 h
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| | halflife = 2.2 h (IR parent); ~3 h (XR parent)
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| | bioavailability = ~22–25%
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| | pregnancy = Category C
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| | legal = Schedule II
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| | intro = '''Dexmethylphenidate''' — marketed as '''Focalin''' and '''Focalin XR''' — is the isolated d-threo enantiomer of [[Methylphenidate|methylphenidate]]. Racemic methylphenidate contains both d- and l-threo enantiomers in equal amounts, but essentially all pharmacologic activity resides in the d-isomer; the l-isomer is rapidly cleared on first-pass and contributes little beyond a possible minor role in peripheral side effects. By delivering only the active enantiomer, Focalin achieves equivalent therapeutic effect at approximately half the milligram dose of racemic methylphenidate, with some patients reporting a cleaner subjective profile (less jitteriness, more focused effect). Its clinical indications, mechanism, contraindications, and adverse-effect profile are otherwise nearly identical to racemic methylphenidate.
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| | pharmacokinetics = '''Absorption:''' Rapid oral absorption; peak plasma in ~1–1.5 h (IR) or ~6.5 h (XR, which has a biphasic release profile with an initial peak around 1.5 h and a second peak ~6.5 h). Bioavailability ~22–25% due to extensive first-pass metabolism. '''Distribution:''' Volume of distribution similar to racemic methylphenidate (~13 L/kg); plasma protein binding ~15%. '''Metabolism:''' Like the racemate, dexmethylphenidate is metabolized primarily by '''carboxylesterase 1 (CES1)''' to ritalinic acid (inactive). This non-CYP metabolic pathway means dexmethylphenidate, like its racemate, has '''few clinically significant CYP-mediated drug interactions'''. '''Elimination:''' Predominantly renal as ritalinic acid; parent half-life 2.2 h (IR) and ~3 h (XR parent). Multi-dose-daily IR dosing or once-daily XR is required for sustained therapeutic effect.
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| | pharmacodynamics = Mechanistically identical to racemic methylphenidate at the molecular level — competitive inhibition of the dopamine and norepinephrine transporters (DAT, NET), increasing synaptic catecholamine concentrations without acting as a transporter substrate (i.e., no reverse transport or vesicular displacement; '''reuptake inhibition only'''). The functional difference is purely stereochemical: dexmethylphenidate provides the same effective amount of pharmacologically active material at half the milligram dose. Minimal effect on serotonin; no MAO inhibition; no significant binding at 5-HT, histamine, or muscarinic receptors.
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| | indications = * Attention-deficit hyperactivity disorder (children ≥6 y, adolescents, and adults)
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| * Off-label: same off-label uses as racemic methylphenidate (treatment-resistant depression augmentation, cancer/HIV/MS fatigue)
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| * Not FDA-approved for narcolepsy (use racemic methylphenidate or an amphetamine for that indication)
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| | dosing = '''Focalin IR:''' Start 2.5 mg PO twice daily (separate doses by at least 4 h). Titrate by 2.5–5 mg/week. Max 20 mg/day (adults and children).
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| '''Focalin XR:''' Start 5 mg PO once daily AM (children), 10 mg PO once daily AM (adults). Titrate weekly. Max 30 mg/day (children); 40 mg/day (adults).
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| '''Conversion from racemic methylphenidate:''' use approximately '''half''' the total daily dose (e.g., Ritalin 20 mg/day → Focalin 10 mg/day).
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| '''Renal/hepatic impairment:''' caution; reduce dose and monitor.
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| | effects = ''Therapeutic:'' improved attention, reduced impulsivity and hyperactivity, increased wakefulness, mild appetite suppression. Many patients describe the effect as cleaner or more "focused" compared with racemic methylphenidate at equivalent therapeutic doses, though objective evidence for superiority is modest.
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| ''Common adverse:'' decreased appetite, insomnia, headache, abdominal pain, mild irritability, dry mouth, mild elevation of heart rate and blood pressure, weight loss.
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| | adverse = * '''Cardiovascular:''' tachycardia, mild–moderate hypertension; rare sudden cardiac death in structural heart disease (FDA warning)
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| * '''Psychiatric:''' anxiety, agitation, irritability; rarely psychosis, mania, or hallucinations (especially in patients with predisposition)
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| * '''Tics''' — may emerge or worsen; comorbid Tourette is a traditional relative contraindication
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| * '''Dependence and misuse''' — Schedule II; abuse liability similar to racemic methylphenidate per milligram of active material
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| * '''Growth suppression''' — modest reduction in growth velocity in chronically-treated children
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| * '''Priapism''' — rare but documented; FDA warning
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| * '''Peripheral vasculopathy''' — Raynaud-like phenomenon, rare digital ischemia
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| * '''Lowered seizure threshold'''
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| * '''Withdrawal / "crash"''' — fatigue, rebound hyperactivity, dysphoria on dose offset
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| | contraindications = * Hypersensitivity to dexmethylphenidate or methylphenidate
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| * Concurrent MAOI use, or within 14 days of MAOI discontinuation
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| * Symptomatic cardiovascular disease, advanced atherosclerosis, moderate–severe hypertension, recent MI
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| * Hyperthyroidism
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| * Glaucoma
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| * Pheochromocytoma
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| * Severe anxiety, tension, or agitation
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| * '''Relative:''' Tourette syndrome / tic disorders, history of substance use disorder, bipolar disorder, psychotic disorders, structural cardiac abnormalities
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| | interactions = * '''MAOIs''' — hypertensive crisis risk; contraindicated within 14 days
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| * '''Tricyclic antidepressants''' — possible elevation of TCA levels; additive cardiovascular effects
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| * '''Warfarin''' — possible elevation of INR
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| * '''Phenytoin, phenobarbital, primidone''' — possible elevation of anticonvulsant levels
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| * '''Antihypertensives''' — pressor effect of dexmethylphenidate may partially antagonize
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| * '''Other sympathomimetics''' (pseudoephedrine, phenylephrine, decongestants) — additive cardiovascular effects
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| * '''Antipsychotics''' — mutual pharmacologic antagonism
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| * '''Alcohol''' — may mask effects; possible increased exposure via altered metabolism
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| * '''Caffeine''' — additive stimulant and anxiogenic effects
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| Like racemic methylphenidate, '''few CYP-mediated interactions''' due to CES1-dominated metabolism.
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| | pregnancy_details = Category C. Crosses the placenta. Reproductive data limited and largely extrapolated from racemic methylphenidate; overall not clearly teratogenic but cohort studies suggest a small increase in cardiac malformations. Third-trimester exposure can produce transient neonatal withdrawal. Risk-benefit decision; many patients defer ADHD treatment during pregnancy. Excreted in breast milk in low amounts; breastfeeding generally compatible at therapeutic doses with infant monitoring.
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| | monitoring = * Baseline: cardiovascular history (including family history of sudden cardiac death), blood pressure, heart rate, weight/height, mental health history, history of tics or substance use
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| * Consider ECG if cardiac risk factors are present
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| * At each visit: blood pressure, heart rate, weight (and height in children), efficacy, side effects, signs of misuse/diversion, tic emergence
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| * Sleep quality and timing of last dose
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| * Periodically reassess continued need; consider drug holidays in children
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| | counseling = * Take in the morning (XR) or twice daily 4+ hours apart (IR); avoid late-afternoon dosing to minimize insomnia.
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| * '''Focalin XR capsules:''' may be swallowed whole or opened and sprinkled on applesauce; '''do not crush or chew the beads inside.'''
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| * Eat regular meals despite appetite suppression; weigh periodically.
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| * Stay well-hydrated.
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| * Do not combine with significant alcohol or other stimulants.
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| * Do not share or sell — Schedule II controlled substance.
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| * Report chest pain, palpitations, severe agitation, hallucinations, prolonged erection, or new/worsening tics.
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| * If switching from racemic methylphenidate, dose conversion is roughly half — confirm with prescriber.
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| * Plan for the "crash" when the dose wears off, especially with IR.
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| | anecdotes =
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| | seealso = [[Methylphenidate]], [[Mixed amphetamine salts]], [[Dextroamphetamine]], [[Lisdexamfetamine]], [[Modafinil]], [[Atomoxetine]], [[Viloxazine]]
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| | references =
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| }}
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