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[[Category:Stimulants & Wake-Promoting Agents]] | |||
[[Category:Methylphenidates (Phenidates)]] | |||
Revision as of 15:06, 14 May 2026
Psychostimulant, CNS stimulant, NDRI
Dexmethylphenidate
Focalin, Focalin XR
Dexmethylphenidate — marketed as Focalin and Focalin XR — is the isolated d-threo enantiomer of 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.
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.
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.
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.
Methylphenidate, Mixed amphetamine salts, Dextroamphetamine, Lisdexamfetamine, Modafinil, Atomoxetine, Viloxazine
Experience
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Problems
- Attention-deficit hyperactivity disorder (children ≥6 y, adolescents, and adults)
- Off-label: same off-label uses as racemic methylphenidate (treatment-resistant depression augmentation, cancer/HIV/MS fatigue)
- Not FDA-approved for narcolepsy (use racemic methylphenidate or an amphetamine for that indication)
Titration strategies
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). 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). Conversion from racemic methylphenidate: use approximately half the total daily dose (e.g., Ritalin 20 mg/day → Focalin 10 mg/day). Renal/hepatic impairment: caution; reduce dose and monitor.
Effects
Therapeutic
- Attention and focus no reports yet no reports yetImproved attention, executive function, and working memory. Many patients report a cleaner subjective effect than racemic methylphenidate at equivalent therapeutic doses.Did you experience this?How often have you seen this?How was it? (-100 worst, +100 best)How was it? (-100 worst, +100 best)
- Reduced impulsivity and hyperactivity no reports yet no reports yetDid you experience this?How often have you seen this?How was it? (-100 worst, +100 best)How was it? (-100 worst, +100 best)
- Wakefulness no reports yet no reports yetDid you experience this?How often have you seen this?How was it? (-100 worst, +100 best)How was it? (-100 worst, +100 best)
Common
- Decreased appetite/Anorexia no reports yet no reports yetOften dose-limiting; may produce weight loss over time.Did you experience this?How often have you seen this?How was it? (-100 worst, +100 best)How was it? (-100 worst, +100 best)
- Insomnia no reports yet no reports yetEspecially with late-afternoon dosing.Did you experience this?How often have you seen this?How was it? (-100 worst, +100 best)How was it? (-100 worst, +100 best)
- Headache no reports yet no reports yetDid you experience this?How often have you seen this?How was it? (-100 worst, +100 best)How was it? (-100 worst, +100 best)
- Abdominal pain no reports yet no reports yetDid you experience this?How often have you seen this?How was it? (-100 worst, +100 best)How was it? (-100 worst, +100 best)
- Irritability no reports yet no reports yetDid you experience this?How often have you seen this?How was it? (-100 worst, +100 best)How was it? (-100 worst, +100 best)
- Dry mouth no reports yet no reports yetDid you experience this?How often have you seen this?How was it? (-100 worst, +100 best)How was it? (-100 worst, +100 best)
- Elevated heart rate / blood pressure no reports yet no reports yetUsually mild but dose-dependent.Did you experience this?How often have you seen this?How was it? (-100 worst, +100 best)How was it? (-100 worst, +100 best)
- Weight loss no reports yet no reports yetDid you experience this?How often have you seen this?How was it? (-100 worst, +100 best)How was it? (-100 worst, +100 best)
Cardiovascular
- Palpitations no reports yet no reports yetDid you experience this?How often have you seen this?How was it? (-100 worst, +100 best)How was it? (-100 worst, +100 best)
- Serious cardiac event no reports yet no reports yetRare reports of sudden cardiac death in patients with structural heart disease (FDA warning).Did you experience this?How often have you seen this?How was it? (-100 worst, +100 best)How was it? (-100 worst, +100 best)
Psychiatric
- Anxiety no reports yet no reports yetDid you experience this?How often have you seen this?How was it? (-100 worst, +100 best)How was it? (-100 worst, +100 best)
- Agitation no reports yet no reports yetDid you experience this?How often have you seen this?How was it? (-100 worst, +100 best)How was it? (-100 worst, +100 best)
- Psychosis no reports yet no reports yetRare; higher risk in patients with bipolar predisposition.Did you experience this?How often have you seen this?How was it? (-100 worst, +100 best)How was it? (-100 worst, +100 best)
- Mania no reports yet no reports yetRare; higher risk in patients with bipolar predisposition.Did you experience this?How often have you seen this?How was it? (-100 worst, +100 best)How was it? (-100 worst, +100 best)
- Hallucinations no reports yet no reports yetVisual or tactile; rare, more common at higher doses or in predisposed patients.Did you experience this?How often have you seen this?How was it? (-100 worst, +100 best)How was it? (-100 worst, +100 best)
Other adverse
- Tics no reports yet no reports yetMay emerge or worsen; comorbid Tourette syndrome is a traditional relative contraindication.Did you experience this?How often have you seen this?How was it? (-100 worst, +100 best)How was it? (-100 worst, +100 best)
- Dependence / misuse no reports yet no reports yetSchedule II controlled substance; abuse liability similar to racemic methylphenidate per milligram of active material. Crushed/insufflated/IV misuse is the major risk pattern.Did you experience this?How often have you seen this?How was it? (-100 worst, +100 best)How was it? (-100 worst, +100 best)
- Tolerance no reports yet no reports yetTo therapeutic effects, with chronic high-dose use.Did you experience this?How often have you seen this?How was it? (-100 worst, +100 best)How was it? (-100 worst, +100 best)
- Growth suppression no reports yet no reports yetModest reduction in growth velocity in chronically-treated children.Did you experience this?How often have you seen this?How was it? (-100 worst, +100 best)How was it? (-100 worst, +100 best)
- Priapism no reports yet no reports yetRare but documented; FDA warning, especially in adolescents.Did you experience this?How often have you seen this?How was it? (-100 worst, +100 best)How was it? (-100 worst, +100 best)
- Peripheral vasculopathy no reports yet no reports yetRaynaud-like phenomenon, rare digital ischemia.Did you experience this?How often have you seen this?How was it? (-100 worst, +100 best)How was it? (-100 worst, +100 best)
- Seizure/Epileptic fit no reports yet no reports yetCaution in epilepsy.Did you experience this?How often have you seen this?How was it? (-100 worst, +100 best)How was it? (-100 worst, +100 best)
- Withdrawal/Discontinuation Syndrome no reports yet no reports yetFatigue, rebound hyperactivity, dysphoria on dose offset.Did you experience this?How often have you seen this?How was it? (-100 worst, +100 best)How was it? (-100 worst, +100 best)
Pharmacokinetics
Pharmacodynamics
Interactions
- MAOIs — hypertensive crisis risk; contraindicated within 14 days
- Tricyclic antidepressants — possible elevation of TCA levels; additive cardiovascular effects
- Warfarin — possible elevation of INR
- Phenytoin, phenobarbital, primidone — possible elevation of anticonvulsant levels
- Antihypertensives — pressor effect of dexmethylphenidate may partially antagonize
- Other sympathomimetics (pseudoephedrine, phenylephrine, decongestants) — additive cardiovascular effects
- Antipsychotics — mutual pharmacologic antagonism
- Alcohol — may mask effects; possible increased exposure via altered metabolism
- Caffeine — additive stimulant and anxiogenic effects
Like racemic methylphenidate, few CYP-mediated interactions due to CES1-dominated metabolism.
No interactions reported yet.
Pregnancy and lactation
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
- Consider ECG if cardiac risk factors are present
- At each visit: blood pressure, heart rate, weight (and height in children), efficacy, side effects, signs of misuse/diversion, tic emergence
- Sleep quality and timing of last dose
- Periodically reassess continued need; consider drug holidays in children
Patient counseling
- Take in the morning (XR) or twice daily 4+ hours apart (IR); avoid late-afternoon dosing to minimize insomnia.
- Focalin XR capsules: may be swallowed whole or opened and sprinkled on applesauce; do not crush or chew the beads inside.
- Eat regular meals despite appetite suppression; weigh periodically.
- Stay well-hydrated.
- Do not combine with significant alcohol or other stimulants.
- Do not share or sell — Schedule II controlled substance.
- Report chest pain, palpitations, severe agitation, hallucinations, prolonged erection, or new/worsening tics.
- If switching from racemic methylphenidate, dose conversion is roughly half — confirm with prescriber.
- Plan for the "crash" when the dose wears off, especially with IR.
Relevant anecdote
No anecdotes yet. Share a relevant one.
Relevant Literature
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See also
Summary
Classes
Psychostimulant, CNS stimulant, NDRI
Common uses
Inattention+1, Productivity+1
Pharmacy
Pharmacology
Routes
Oral
Onset
30–60 min
Duration
IR 4–6 h; XR 8–12 h
Half-life
2.2 h (IR parent); ~3 h (XR parent)
Bioavailability
~22–25%
Pregnancy
Category C
Legal status
Schedule II
Purported mechanism
Norepinephrine–dopamine reuptake inhibition (DAT, NET) — d-threo enantiomer of methylphenidate
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.
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.
Indications
- Attention-deficit hyperactivity disorder (children ≥6 y, adolescents, and adults)
- Off-label: same off-label uses as racemic methylphenidate (treatment-resistant depression augmentation, cancer/HIV/MS fatigue)
- Not FDA-approved for narcolepsy (use racemic methylphenidate or an amphetamine for that indication)
Dosing and titration
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). 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). Conversion from racemic methylphenidate: use approximately half the total daily dose (e.g., Ritalin 20 mg/day → Focalin 10 mg/day).
Renal/hepatic impairment: caution; reduce dose and monitor.
Effects
Therapeutic
- Attention and focus no reports yet no reports yetImproved attention, executive function, and working memory. Many patients report a cleaner subjective effect than racemic methylphenidate at equivalent therapeutic doses.Did you experience this?How often have you seen this?How was it? (-100 worst, +100 best)How was it? (-100 worst, +100 best)
- Reduced impulsivity and hyperactivity no reports yet no reports yetDid you experience this?How often have you seen this?How was it? (-100 worst, +100 best)How was it? (-100 worst, +100 best)
- Wakefulness no reports yet no reports yetDid you experience this?How often have you seen this?How was it? (-100 worst, +100 best)How was it? (-100 worst, +100 best)
Common
- Decreased appetite/Anorexia no reports yet no reports yetOften dose-limiting; may produce weight loss over time.Did you experience this?How often have you seen this?How was it? (-100 worst, +100 best)How was it? (-100 worst, +100 best)
- Insomnia no reports yet no reports yetEspecially with late-afternoon dosing.Did you experience this?How often have you seen this?How was it? (-100 worst, +100 best)How was it? (-100 worst, +100 best)
- Headache no reports yet no reports yetDid you experience this?How often have you seen this?How was it? (-100 worst, +100 best)How was it? (-100 worst, +100 best)
- Abdominal pain no reports yet no reports yetDid you experience this?How often have you seen this?How was it? (-100 worst, +100 best)How was it? (-100 worst, +100 best)
- Irritability no reports yet no reports yetDid you experience this?How often have you seen this?How was it? (-100 worst, +100 best)How was it? (-100 worst, +100 best)
- Dry mouth no reports yet no reports yetDid you experience this?How often have you seen this?How was it? (-100 worst, +100 best)How was it? (-100 worst, +100 best)
- Elevated heart rate / blood pressure no reports yet no reports yetUsually mild but dose-dependent.Did you experience this?How often have you seen this?How was it? (-100 worst, +100 best)How was it? (-100 worst, +100 best)
- Weight loss no reports yet no reports yetDid you experience this?How often have you seen this?How was it? (-100 worst, +100 best)How was it? (-100 worst, +100 best)
Cardiovascular
- Palpitations no reports yet no reports yetDid you experience this?How often have you seen this?How was it? (-100 worst, +100 best)How was it? (-100 worst, +100 best)
- Serious cardiac event no reports yet no reports yetRare reports of sudden cardiac death in patients with structural heart disease (FDA warning).Did you experience this?How often have you seen this?How was it? (-100 worst, +100 best)How was it? (-100 worst, +100 best)
Psychiatric
- Anxiety no reports yet no reports yetDid you experience this?How often have you seen this?How was it? (-100 worst, +100 best)How was it? (-100 worst, +100 best)
- Agitation no reports yet no reports yetDid you experience this?How often have you seen this?How was it? (-100 worst, +100 best)How was it? (-100 worst, +100 best)
- Psychosis no reports yet no reports yetRare; higher risk in patients with bipolar predisposition.Did you experience this?How often have you seen this?How was it? (-100 worst, +100 best)How was it? (-100 worst, +100 best)
- Mania no reports yet no reports yetRare; higher risk in patients with bipolar predisposition.Did you experience this?How often have you seen this?How was it? (-100 worst, +100 best)How was it? (-100 worst, +100 best)
- Hallucinations no reports yet no reports yetVisual or tactile; rare, more common at higher doses or in predisposed patients.Did you experience this?How often have you seen this?How was it? (-100 worst, +100 best)How was it? (-100 worst, +100 best)
Other adverse
- Tics no reports yet no reports yetMay emerge or worsen; comorbid Tourette syndrome is a traditional relative contraindication.Did you experience this?How often have you seen this?How was it? (-100 worst, +100 best)How was it? (-100 worst, +100 best)
- Dependence / misuse no reports yet no reports yetSchedule II controlled substance; abuse liability similar to racemic methylphenidate per milligram of active material. Crushed/insufflated/IV misuse is the major risk pattern.Did you experience this?How often have you seen this?How was it? (-100 worst, +100 best)How was it? (-100 worst, +100 best)
- Tolerance no reports yet no reports yetTo therapeutic effects, with chronic high-dose use.Did you experience this?How often have you seen this?How was it? (-100 worst, +100 best)How was it? (-100 worst, +100 best)
- Growth suppression no reports yet no reports yetModest reduction in growth velocity in chronically-treated children.Did you experience this?How often have you seen this?How was it? (-100 worst, +100 best)How was it? (-100 worst, +100 best)
- Priapism no reports yet no reports yetRare but documented; FDA warning, especially in adolescents.Did you experience this?How often have you seen this?How was it? (-100 worst, +100 best)How was it? (-100 worst, +100 best)
- Peripheral vasculopathy no reports yet no reports yetRaynaud-like phenomenon, rare digital ischemia.Did you experience this?How often have you seen this?How was it? (-100 worst, +100 best)How was it? (-100 worst, +100 best)
- Seizure/Epileptic fit no reports yet no reports yetCaution in epilepsy.Did you experience this?How often have you seen this?How was it? (-100 worst, +100 best)How was it? (-100 worst, +100 best)
- Withdrawal/Discontinuation Syndrome no reports yet no reports yetFatigue, rebound hyperactivity, dysphoria on dose offset.Did you experience this?How often have you seen this?How was it? (-100 worst, +100 best)How was it? (-100 worst, +100 best)
Contraindications
- Hypersensitivity to dexmethylphenidate or methylphenidate
- Concurrent MAOI use, or within 14 days of MAOI discontinuation
- Symptomatic cardiovascular disease, advanced atherosclerosis, moderate–severe hypertension, recent MI
- Hyperthyroidism
- Glaucoma
- Pheochromocytoma
- Severe anxiety, tension, or agitation
- Relative: Tourette syndrome / tic disorders, history of substance use disorder, bipolar disorder, psychotic disorders, structural cardiac abnormalities
Interactions
- MAOIs — hypertensive crisis risk; contraindicated within 14 days
- Tricyclic antidepressants — possible elevation of TCA levels; additive cardiovascular effects
- Warfarin — possible elevation of INR
- Phenytoin, phenobarbital, primidone — possible elevation of anticonvulsant levels
- Antihypertensives — pressor effect of dexmethylphenidate may partially antagonize
- Other sympathomimetics (pseudoephedrine, phenylephrine, decongestants) — additive cardiovascular effects
- Antipsychotics — mutual pharmacologic antagonism
- Alcohol — may mask effects; possible increased exposure via altered metabolism
- Caffeine — additive stimulant and anxiogenic effects
Like racemic methylphenidate, few CYP-mediated interactions due to CES1-dominated metabolism.
Pregnancy and lactation
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.
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
- Consider ECG if cardiac risk factors are present
- At each visit: blood pressure, heart rate, weight (and height in children), efficacy, side effects, signs of misuse/diversion, tic emergence
- Sleep quality and timing of last dose
- Periodically reassess continued need; consider drug holidays in children
Patient counseling
- Take in the morning (XR) or twice daily 4+ hours apart (IR); avoid late-afternoon dosing to minimize insomnia.
- Focalin XR capsules: may be swallowed whole or opened and sprinkled on applesauce; do not crush or chew the beads inside.
- Eat regular meals despite appetite suppression; weigh periodically.
- Stay well-hydrated.
- Do not combine with significant alcohol or other stimulants.
- Do not share or sell — Schedule II controlled substance.
- Report chest pain, palpitations, severe agitation, hallucinations, prolonged erection, or new/worsening tics.
- If switching from racemic methylphenidate, dose conversion is roughly half — confirm with prescriber.
- Plan for the "crash" when the dose wears off, especially with IR.{{#if:
Personal experience
The following are personal accounts and not medical advice.
Discussion (0)
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