Pharm

Atomoxetine

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Atomoxetine, Strattera

  • Contraindications
  1. Narrow-angle Glaucoma
  2. Concurrent MAO inhibitor use
  • Precautions
  1. Increased Suicidality in children and teens (FDA black box warning)
  • Mechanism
  1. Selective Norepinephrine reuptake inhibitor
  2. Non-stimulant (not a controlled substance)
  • Pharmacokinetics
  1. Peak serum concentration
    1. Without food: 1 hour
    2. With food: 3 hours
  2. Metabolized by CYP2D6
  3. Half-life
    1. Most patients: 5 hours
    2. CYP2D6 defect (5-10%): 24 hours
  4. Adjust dose to 50% if Hepatic dysfunction
  • Dosing
  • Indicated for ADHD in Age 6 years and older
  1. Timing
    1. Once daily dosing or
    2. Split daily dose to bid (morning and late afternoon)
  2. Weight <70 kg
    1. Initial: 0.5 mg/kg/day
    2. Increase after 3 days to 1.2 mg/kg/day
      1. Delay increasing dose if on CYP2D6 inhibitor
      2. See Drug Interactions below
    3. Maximum: 1.4 mg/kg/day up to 100 mg
  3. Weight >70 kg
    1. Initial: 40 mg/day
    2. Increase after 3 days to 80 mg/day
      1. Delay increasing dose if on CYP2D6 inhibitor
      2. See Drug Interactions below
    3. Maximum: 100 mg/day or 1.4 mg/kg
  • Efficacy
  • Not considered a first line agent
  • Adverse Effects
  1. Severe liver injury
    1. Serious reactions, but case reports only as of 2005
    2. Observe clinically, but no routine LFT monitoring
    3. (February 2005) Prescriber's Letter, p. 8
  2. Abdominal Pain
  3. Gastrointestinal upset
    1. Nausea
    2. Vomiting (more than with Methylphenidate)
  4. Diminished appetite
  5. Dizziness
  6. Somnolence (more than with Methylphenidate)
  7. Weight loss (3.5% weight loss in 20% of patients)
  8. Anticholinergic effects in adults
    1. Dry Mouth
    2. Constipation
    3. Urinary Retention
    4. Sexual Dysfunction
  • Drug Interactions
  1. MAO inhibitor
  2. Concurrent use of potent CYP2D6 inhibitors
    1. Paroxetine (Paxil)
    2. Fluoxetine (Prozac)
    3. Quinidine
  • Preparations
  1. Capsules: 10 mg, 18 mg, 25 mg, 40 mg, 60 mg
  • References
  1. (2003) Lexi-Comp Drug Database for Pocket PC (7/9/03)
  2. (2003) Med Lett Drugs Ther 45(1149):11-2 [PubMed]