Amoxapine , AMOXAPINE® , ASENDIN®

Brand name

  • Amoxapine®: only generic formulations are available in the US
  • Asendin®: previously marketed in CA, US

Drug Class

  • Tricyclic anti-depressants (TCAs)

Preparations

  • Tablets 25mg/50mg/100mg/150mg

Indications

1- Major Depressive Disorder (MDD)

2- Neurotic or reactive depressive disorders

3- Endogenous depression

4- Depression accompanied by anxiety or agitation

Pharmacology

  • Mechanisem of action: Exact mechanism of action unknown; inhibits norepinephrine and serotonin reuptake

Metabolism

  • Metabolism: liver; CYP450
  • Absorption: almost complete absorption
  • Distribution: Half-life: 8h (amoxapine), 30h (8-hydroxyamoxapine). Plasma peak >>> 90 min. 90% binds to plasma proteins
  • Excretion: urine 60%, feces 18%

Dosing

Depression: (Adult only!)

  • Initial dose: 25 mg every 8 -12 hour >>> gradual increase every 5-7 days to 200-300 mg/day qHS ( incase neede more tham 300mg, divide the doses)
  • Max Outpatient dose: 400mg/day
  • Max Inpatient dose: 600 mg/day divided q12hr

Drug Interactions

  • Monoamine oxidase inhibitors
  • Aripiprazole
  • Amphetamine / Dextroamphetamine
  • Aspirin
  • Lorazepam
  • Calcium 600 D (Calcium / Vitamin D)
  • Duloxetine
  • Fluconazole
  • Cyclobenzaprine
  • Lurasidone
  • Promethazine
  • Lansoprazole
  • Omeprazole
  • Albuterol
  • Fluoxetine
  • Nabumetone
  • Vortioxetine
  • Diazepam
  • Vilazodone
  • Bupropion

Adverse Effects

Very common (>10% incidence) adverse effects:

  • Constipation
  • Dry mouth
  • Sedation

 


Common (1-10% incidence) adverse effects:

  • Anxiety
  • Ataxia
  • Blurred Vision
  • Confusion
  • Dizziness
  • Headache
  • Fatigue
  • Nausea
  • Nervousness
  • Restlessness
  • Rash
  • Tremor
  • Palpitation
  • Nightmares
  • ECG changes
  • Edema
  • Increased sweating
  • Increased Prolactin

Contraindications

1-Known hypersensitivity to Amoxapine or other dibenzoxazepine-derivative like TCAs

2- Monoamine oxidase inhibitors

3- Uncorrected narrow angle glaucoma

4- Severe cardiovascular disorders (potential of cardiotoxic adverse effects such as QT interval prolongation)

Pregnancy and Breastfeeding

Pregnancy: Category C

Lactation: Not recommended in nursing mothers

Precautions

1. Caution in concomitant use with Monoamine oxidase inhibitors >>> at least 2 weeks should be elapsed.


2. Caution for worsening of depression and the emergence of suicidality in certain patients during the early phases of treatment


3. Caution for Angle-Closure Glaucoma


4. Tardive Dyskinesia: Amoxapine is not an antipsychotic, but it has substantive neuroleptic activity >>> caution especially in elderlies!


5. Caution!! Amoxapine may cause Neuroleptic Malignant Syndrome (NMS) >>> Amoxapine is not an antipsychotic, but it has substantive neuroleptic activity >>> caution especially in elderlies!


6. Safety and effectiveness in the pediatric population have not been established.


7. Caution in patients with hepatic or renal impairment


8. Over-dosage Signs and Symptoms: Amoxapine overdosage differ significantly from those of other tricyclic antidepressants:

  • Serious cardiovascular effects are seldom if ever observed. However, CNS effects – particularly grand mal convulsions – occur frequently, and treatment should be directed primarily toward prevention or control of seizures.
  • No universal antidote, >>> Do symptomatic and supportive treatment

Section

This document is prepared by the “Mental Health for All” team. This document is provided for information purposes only and does not necessarily represent endorsement by or an official position of the Essentials of Medicine. Advice on the treatment or care of an individual patient should be obtained through consultation with a physician who has examined that patient or is familiar with that patient’s medical history.

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