Methylin

(methylphenidate hydrochloride, immediate-release)
Methylin (methylphenidate hydrochloride, immediate-release); CII
Full Prescribing Information
DailyMed Drug Information
Summary
Methylin is immediate-release methylphenidate supplied as a grape-flavoured oral solution, approved for ADHD in patients 6 years and older and for narcolepsy, with generic chewable tablets at 2.5 mg, 5 mg and 10 mg. Its differentiator is dose granularity for a child who cannot swallow: the solution measures to fractions of a milligram, which no tablet in the class can do. Schedule II; oral solution brand and generic, chewable tablet generic only.
Forms & Strengths
Oral solution (grape, colorless): 5 mg/5 mL and 10 mg/5 mL
Chewable tablets (grape): 2.5 mg, 5 mg, 10 mg
Dosing
Age:
ADHD: >= 6y
Narcolepsy: no age floor
Onset: ~ 1 hour
Duration: 3 to 4 hours
Initial Dose:
>= 6 y/o and older: 5 mg twice daily, before breakfast and before lunch
Adults: 20 to 30 mg daily in 2 or 3 divided doses, 30 to 45 minutes before meals.
Titration: 5 - 10 mg every 7 days
Max Dose: 60 mg/day
Considerations: The chewable tablet must be taken with at least 8 ounces of fluid because it swells and can cause choking, and it contains phenylalanine.
Pharmacology
Mechanism: Blocks presynaptic dopamine and norepinephrine reuptake at DAT and NET; does not meaningfully promote catecholamine release at therapeutic doses
Delivery / Release: Immediate release, no modified-release component in either form. Solution and IR tablet are near-bioequivalent at 20 mg.
Metabolism: De-esterified to ritalinic acid, essentially inactive. Protein binding 10% to 33%. Mean terminal half-life 2.7 hours, the shortest methylphenidate in this library.
Food effect: a high-fat meal raises solution Cmax ~13% and AUC ~25% and delays Tmax by about an hour, a smaller effect than on Metadate CD.
Class Positioning: The only methylphenidate titratable in fractions of a milligram, and the most reversible. Compare Ritalin (IR tablet) and QuilliChew ER, an extended-release chewable not to be confused with this one.
Indications
ADHD (ICD-10: F90.0, F90.1, F90.2, F90.8, F90.9): patients 6 y/o and older, and adults
Narcolepsy (ICD-10: G47.419): no age floor
Off-Label Uses
ADHD in children 4 to 5 years old (ICD-10: F90.x): behavioral therapy first line; IR methylphenidate from a low dose where it fails. Expert consensus. (AAP 2019)
Afternoon top-up alongside a long-acting methylphenidate (ICD-10: F90.x): coherent given the 3 to 4 hour window; 60 mg/day ceiling applies to the sum. Limited data. (AHRQ 2024)
Where the evidence does not support use: binge eating disorder (F50.2), treatment-resistant depression (F33.9), cancer-related and other fatigue (R53.0, R53.83). Adult literature only; insufficient in children. (AHRQ 2024)
Cognitive enhancement in a youth without ADHD: not an indication and not supported.
Contraindications & Warnings
Boxed Warning: Abuse, misuse and addiction, with overdose and death; risk rises with dose and non-oral routes. Assess abuse risk before prescribing and reassess throughout.
Contraindicated:
Hypersensitivity to methylphenidate or any component
MAOI use, current or within 14 days: hypertensive crisis
Chewable tablet only: difficulty swallowing. Use the oral solution.
Use with caution:
Structural cardiac abnormality, cardiomyopathy, serious arrhythmia or coronary disease: avoid
Pre-existing hypertension: monitor blood pressure and pulse
Psychotic or bipolar disorder: exacerbation and treatment-emergent mania
Significant hyperopia or angle-closure risk: refer to ophthalmology
Personal or family history of tics or Tourette's syndrome
Phenylketonuria, chewable only: 0.42 / 0.84 / 1.68 mg phenylalanine per 2.5 / 5 / 10 mg tablet
Substance use disorder in patient or household; a 500 mL CII bottle is hard to audit
Screen before starting:
Cardiac history and exam including family sudden death; the label requires the screen, not an ECG
Tics, mania risk factors, and abuse or diversion risk in patient and household
Swallowing ability, which decides the form; PKU if a chewable is considered
Baseline height, weight, BP and HR
Drug Interactions
MAOIs (phenelzine, tranylcypromine, selegiline, linezolid, methylene blue): hypertensive crisis. Contraindicated within 14 days.
Antihypertensives: effectiveness reduced. Increase BP monitoring and adjust the antihypertensive.
Halogenated anesthetics (sevoflurane, isoflurane, desflurane): intraoperative BP and HR surge. Hold all doses on the day of surgery.
Risperidone: EPS may increase when either dose changes in either direction. Monitor across any titration.
Serotonergic agents (SSRIs, SNRIs, TCAs, triptans, tramadol): serotonin syndrome in postmarketing reports only. Counsel on symptoms rather than avoiding.
Venlafaxine: one pediatric NMS-like report after a first dose. Watch the first days of any new serotonergic agent.
Administration
Give 30 to 45 minutes before meals, which is a labeled instruction.
Before breakfast and before lunch; add a third dose for afternoon coverage. Last dose before 6 p.m. if sleep is affected.
Oral solution: measure with an oral syringe or calibrated cup, never a kitchen spoon. The two strengths look identical; state the concentration on every prescription.
Chewable tablet: chew well, swallow with at least 8 ounces of fluid; it swells and can obstruct the throat.
Missed dose: give only if the next is several hours away and it is not late. Never double up.
Store locked. A flavoured CII liquid is the form a younger sibling is likeliest to drink.
Side Effects
Common: tachycardia, palpitations, headache, insomnia, anxiety, hyperhidrosis, decreased appetite, weight loss, dry mouth, nausea, abdominal pain. No pediatric percentages published.
Serious:
Choking or esophageal obstruction from a chewable taken dry: emergency, unique to that form
Sudden death with structural cardiac disease: avoid in that population
New psychosis or mania, including with no psychiatric history: consider discontinuing
Priapism, sometimes surgical, including during drug holidays and withdrawal
Peripheral vasculopathy and Raynaud's with digital ulceration: assess digits each visit
Long-term growth suppression; angle-closure glaucoma; new or worsening tics
Postmarketing: seizures, dyskinesia, cerebral arteritis, hepatic injury, leukopenia, thrombocytopenic purpura, erythema multiforme, rhabdomyolysis, NMS
Monitoring & Labs
Concentration and measuring device: confirm at every visit and refill; the twofold strength difference is this page's likeliest dosing error.
Adherence: confirm at every visit that the midday dose is given; a missed school dose mimics loss of efficacy.
Growth: height, weight and BMI at baseline and every 6 months; every visit if losing weight.
Cardiovascular: BP and HR at baseline, at every dose change, and at least every 6 months.
Appetite and sleep: at every visit and dose change; ask the time of the last dose.
Psychiatric and tics: screen for psychosis, mania, aggression, depressed mood and tics at baseline and every visit.
Abuse and diversion: at every refill, ask about sharing and selling and check the PDMP. Reconcile volume remaining against days elapsed; a bottle cannot be pill-counted.
Laboratory: none required. Check liver enzymes only for jaundice, dark urine or unexplained abdominal pain.
Discontinuation & Taper
No taper required; neither label gives a tapering schedule.
Discontinue if no improvement after appropriate dose adjustment over one month.
Withdrawal after prolonged use: dysphoria, fatigue, vivid dreams, sleep change, increased appetite.
Priapism has occurred during drug holidays and on discontinuation.
Drug holidays are easiest here: the solution can be part-dosed as well as part-scheduled.
Pregnancy & Lactation
Pregnancy: no drug-associated risk of major birth defects or miscarriage identified. Stimulant vasoconstriction may reduce placental perfusion. Background risk 2% to 4% and 15% to 20%. Weigh against untreated maternal ADHD.
Lactation: infant dose 0.16% to 0.7% of the maternal weight-adjusted dose; undetectable in infant plasma in every reported case. Not a reason to stop breastfeeding. (LactMed 2025)
Lactation, milk supply: prolactin falls; large doses may interfere before supply is established. Monitor the infant for agitation, insomnia and poor weight gain. (LactMed 2025)
Exposure Registry: National Pregnancy Registry for Psychostimulants, 1-866-961-2388.
Counseling Points
Counsel the family on:
The two concentrations: the same 5 mL is 5 mg or 10 mg depending on the bottle. Check every refill, and measure only with the supplied syringe.
The chewable needing a full 8 ounce glass every time; chewed dry it swells and can block the throat.
The 3 to 4 hour window: the lunchtime dose is part of the plan, not a sign the first failed.
Rebound irritability and hunger several times a day: expected, not a reason to raise the dose.
Locking up the bottle; a flavoured CII liquid is the easiest form to lose unnoticed.
Bringing a teacher rating scale, morning and afternoon rated separately.
Advise them to call for:
Chest pain, vomiting or trouble swallowing after a chewable: emergency
Chest pain, fainting, or a racing heart that does not settle
New hallucinations, or new suspicious or fearful thinking
Numbness, coldness or colour change in fingers or toes, or a sore that will not heal
A new or markedly worse tic, including throat clearing and blinking
A painful erection lasting more than a few hours, including during a break
Any amount of the solution swallowed by another child in the house
References
DailyMed. Methylin (methylphenidate hydrochloride) oral solution prescribing information. Shionogi Inc. 2023. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=9e3c22d9-71d9-46a7-b315-8021c94c4bec
DailyMed. Methylphenidate hydrochloride chewable tablets prescribing information. Lupin Pharmaceuticals. 2023. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=5bfe50ed-171f-4c40-bc0b-20c68e8e2025
FDA. openFDA National Drug Code Directory, generic_name methylphenidate. 2026. https://api.fda.gov/drug/ndc.json?search=generic_name:%22methylphenidate%22&limit=1000
LactMed. Methylphenidate. Drugs and Lactation Database, NICHD. 2025. https://www.ncbi.nlm.nih.gov/books/NBK501310/
American Academy of Pediatrics. Clinical practice guideline for the diagnosis, evaluation, and treatment of ADHD in children and adolescents. Pediatrics. 2019. https://publications.aap.org/pediatrics/article/144/4/e20192528/81590/
AHRQ. Attention deficit hyperactivity disorder: diagnosis and treatment in children and adolescents. Comparative Effectiveness Review No. 267. 2024. https://www.ncbi.nlm.nih.gov/books/NBK602989/