Pharm

Atypical Antipsychotic Overdose

search

Atypical Antipsychotic Overdose

  • Epidemiology
  1. Atypical Antipsychotic Overdose is common in U.S.
    1. Incidence: >43,000 poison control related cases in 2009
  • Findings
  1. CNS Effects
    1. Sedation (common)
    2. Neuroleptic Malignant Syndrome (rare with Overdose)
  2. Anticholinergic Toxicity (antimuscarinic symptoms)
    1. Most common with Clozapine, Olanzapine, quetipaine
    2. Less common with Risperidone, Ziprasidone, Aripiprazole
    3. Hyperthermia
    4. Tachycardia
    5. Blurred Vision
    6. Skin flushed and dry
    7. Agitation
    8. Hallucinations
    9. Urine retention
  3. Cardiac Effects
    1. Hypotension (most common)
    2. Tachycardia
    3. QTc Prolongation (and risk of Torsades)
      1. See Prolonged QT Interval due to Medication
      2. See Antipsychotic for specific agent propensity for QTc Prolongation
  4. Specific agent effects in Overdose
    1. Risperidone
      1. Dystonic Reaction
      2. Delayed respiratory depression
    2. Olanzapine
      1. Fluctuating mental status (Agitation, sedation)
      2. Creatine Phosphokinase increase
  • Diagnostics
  1. Electrocardiogram (EKG)
  • Labs
  1. See Unknown Ingestion
  2. Basic metabolic panel
  3. Serum Creatine Phosphokinase
  4. Serum Magnesium
  5. Venous Blood Gas
  6. Toxicology Screening
    1. Salicylate Level
    2. Acetaminophen Level
    3. Alcohol level
  • Management
  1. See Unknown Ingestion
  2. ABC Management and stabilization
  3. Stop causative agent
  4. Correct lab abnormalities
  5. Consider other ingested agents
  6. Gastric Decontamination (controversial, consider in first hour of ingestion)
    1. May discuss with poison control
    2. Consider Activated Charcoal if presentation within first hour AND alert or intubated
    3. Whole Bowel Irrigation might be considered for long-acting agents such as palpiperidone
  7. Anticholinergic Toxicity
    1. See Anticholinergic Toxicity
    2. Benzodiazepines for Agitation or Seizure
    3. Consider Physostigmine
  8. Other measures
    1. Lipid emulsion (Intralipid)
      1. Most Atypical Antipsychotics are lipophillic
      2. Consider in severe Overdose
  9. Disposition
    1. Most agents are cleared within 6 hours of ingestion (except Paliperidone and Aripiprazole)
    2. If no serious findings at 6 hours, may be dispositioned home
  • References
  1. Glauser and Peters (2016) Crit Dec Emerg Med 30(4): 17-27