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