Methylphenidate

Aka: Methylphenidate, Ritalin, Methylin, Concerta

1. Indications: Methylphenidate (Ritalin)
   1. Attention Deficit Hyperactivity Disorder (ADHD)
   2. Narcolepsy
   3. Depression in medically ill elderly patients
   4. Enhanced pain control in patients on opiates
2. Contraindications
   1. See Drug interactions below
   2. Congenital heart defect (ask related PMH, Family History and screen on ADHD exam)
      1. Consider an EKG before prescribing
      2. Vetter (2008) Circulation 117(18):2407-23.
   3. Motor Tics or Tourette's Syndrome
   4. Glaucoma
   5. Seizure disorder
   6. Hypertension
   7. Pregnancy
3. Pharmacokinetics: Methylphenidate
   1. Immediate Release: Ritalin-IR, Methylin IR
      1. Onset of action: within 20 to 60 minutes of dose
      2. Peaks at 1.9 hours on average
      3. Duration: 3 to 6 hours
   2. Immediate Release: Focalin (Dexmethylphenidate)
      1. D-isomer of Ritalin (l-isomer is inactive)
      2. Prescribed at half dose of Ritalin
      3. Same pharmacokinetics as immediate release Methylphenidate
      4. Fewer Headaches but more Stomache pain than with Methylphenidate
   3. Long-Acting: Ritalin-LA
      1. Duration: 8 hours
      2. Biphasic release
         1. Immediate release: 50%
         2. Modified release beads: 50%
      3. Preferred over Ritalin SR
   4. Long-Acting: Ritalin-SR, Metadate ER, Methylin ER
      1. Onset of action: within 90 minutes of dose
      2. Peaks at 3 hours on average
      3. Duration: 5-8 hours (gradual decrease after 3 hours)
      4. Less effective than Ritalin IR bid
      5. Other sustained release forms are preferred
   5. Very-Long-Acting: Concerta
      1. Onset of action: within 60 to 120 minutes of dose
      2. Duration: 12 hours
      3. Comparable to Ritalin-IR tid
   6. Very-Long-Acting: Metadate-CD
      1. Flat concentration curve despite biphasic release
      2. Duration: 8-10 hours
      3. Biphasic peaks at 1.5 hours and again at 4.5 hours
         1. Immediate release beads: 30%
         2. Extended release beads: 70%
4. Dosing: Children (over age 6 years)
   1. Maximum total daily dose: 60 mg/day
   2. Immediate Release: Methylphenidate
      1. Usual Range: 0.5 - 1 mg/kg/day
      2. Start: 2.5 to 5 mg per dose, twice daily
      3. Initial Schedule (lasts 4 hours - dose up to 4 times daily)
         1. Morning: 2.5 to 5 mg PO 30 minutes before breakfast
         2. Noon: 2.5 to 5 mg PO 30 minutes before lunch
         3. Afternoon: 1.25 to 2.5 mg PO at 3-4 pm
      4. Titrate dose up weekly
         1. Increase dose by 0.1 mg/kg/dose (or 5-10 mg/day)
      5. Maximum dose: 2 mg/kg/day or 60 mg/day (some sources suggest maximum up to 90)
   3. Immediate Release: Focalin (Dexmethylphenidate)
      1. Start: 2.5 mg orally twice daily
      2. Usual Dose: 5-10 mg orally twice daily
      3. Maximum Dose: 20 mg orally daily
   4. Sustained Release
      1. Concerta 18 to 54 mg orally daily
         1. Start: 18 mg qAM
         2. May increase weekly by 18 mg/day
         3. Conversions
            1. Ritalin 5 mg or 20 mg SR: Concerta 18 mg
            2. Ritalin 10 mg or 40 mg SR: Concerta 36 mg
            3. Ritalin 15 mg or 60 mg SR: Concerta 54 mg
         4. Maximum: 72 mg/day
      2. Ritalin LA or Metadate CD
         1. Start: 20 mg orally daily
         2. May increase weekly by 10-20 mg/day
         3. Usual dose: 20-40 mg orally once daily
         4. Maximum: 60 mg/day
      3. Ritalin-SR (Other long-acting agents are preferred)
         1. Dose: 0.6 to 2 mg/kg up to 20-40 mg orally daily
         2. Dose is directly converted from Regular Ritalin
         3. Conversion to Ritalin SR (Metadate ER, Methylin ER)
         4. Administer cumulative 8 hour regular dose
         5. Example: Conversion
            1. Child takes Ritalin 10 mg, 5 mg, and 5 mg
            2. Ritalin SR dosing will be 20 mg qAM
         6. Example: Schedule
            1. Morning: 20-40 mg orally
            2. Early afternoon: 20 mg orally
      4. Daytrana (Methylphenidate patch)
         1. Start: 10 mg patch worn 9 hours daily
         2. Max: 30 mg patch worn 9 hours daily
         3. Skin irritation or rash may occur
5. Dosing: Adults with ADHD or Narcolepsy
   1. Maximum total daily dose: 90 mg
   2. Regular Release: 5 to 20 mg PO bid to tid at meals
   3. Sustained Release: 20 mg PO up to q8 hours
6. Dosing: Elderly with comorbid Depression
   1. Maximum total daily dose: 30 mg
   2. Regular Release: 5 to 10 mg bid to tid
7. Drug Interactions
   1. Avoid concurrent Decongestant use
   2. Avoid within 14 days of MAO inhibitor
8. Monitoring
   1. Height
   2. Weight
   3. Blood Pressure
   4. Pulse
9. Adverse Effects
   1. Rebound ADHD behavior when medication level wanes
   2. Emotional lability, irritability or tearfulness
   3. Social withdrawal
   4. Flat affect
   5. Insomnia
   6. Poor appetite
   7. Stomach pain
   8. Unintentional Weight Loss
   9. Reduced growth velocity
   10. Headache
   11. Psychosis (at excessive doses)
10. References
    1. (2002) Lexicomp Drug Database
    2. (1996) Pediatrics 98:301-4
    3. Andesman (1999) Pediatr Clin North Am 46:945-63
    4. Bennett (1999) Pediatr Clin North Am 46:929-44
    5. Challman (2000) Mayo Clin Proc 75:711-21