Amitriptyline

Administration

  • Type: Tricyclic antidepressant
  • Dosage Forms: tablet, injectable solution
  • Routes of Administration: PO, IM
  • Common Trade Names: Elavil, Levate

Adult Dosing

  • 50-100-300mg daily, in 1-3 doses

Pediatric Dosing

Safety/efficacy not established in children <12yo

  • >12yo: 10mg TID and 20mg qHS

Special Populations

  • Pregnancy Rating: C
  • Lactation risk: Infant risk cannot be ruled out
  • Renal dosing: TCAs like amitryptyline don't require dose adjustment in mild or moderate renal impairment but are often avoided in kidney disease because of the increased risk for adverse cardiac side effects such as arrhythmias.
  • Hepatic dosing: avoid in patients with liver failure and use with caution in those with impaired liver function, as lower doses may be required to reach therapeutic serum levels since TCAs like amitryptyline are metabolized by the liver

Contraindications

  • Allergy to class/drug
  • Use of MAOIs concomitantly or within 14 days
  • Recent MI
  • Concomitant use of cisapride

Adverse Reactions

Serious

  • Prolonged QT, dysrhythmia, MI, sudden cardiac death
  • Agranulocytosis
  • Hepatotoxicity
  • Neuroleptic malignant syndrome
  • Seizure
  • Worsening depression, suicidality

Common

  • Somnolence, dizziness
  • Headache
  • Constipation, xerostomia
  • Blurred vision
  • Weight gain

Pharmacology

  • Half-life: 9 - 27 hours
  • Metabolism: Hepatic via CYP2D6
  • Excretion: Urine, small amounts in feces

Mechanism of Action

Neurotransmitter (especially norepinephrine and serotonin) reuptake inhibitor; anticholinergic

Comments

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References