Barbiturate Toxicity Clinical Presentation

Updated: Jan 23, 2021
  • Author: Keith A Lafferty, MD; Chief Editor: Michael A Miller, MD  more...
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As with any overdose, it is important to attempt to ascertain the exact substance and quantity ingested, the time of ingestion and possible co-intoxicants, especially synergistic toxins such as alcohol or other sedatives. Remember that some barbiturates are included in combination drugs (eg, Fioricet [butalbital, acetaminophen]; Donnatal [phenobarbital, hyoscyamine, scopolamine, atropine]) with components that have their own toxicity profile.

Other important aspects of the history include the following:

  • Determine if the barbiturate overdose represents a suicide attempt.
  • Do not overlook the patient's medical history. Most notably, a history of liver disease could potentially result in prolongation of toxic effects.
  • The depressed mental status patient may harbor intracranial and cervical injury from innocuous trauma.

Physical Examination

A full physical examination is warranted in any overdose. Record vital signs. The patient with barbiturate toxicity may present with any or all of the signs and symptoms listed delow.

Neurologic manifestations may include the following:

  • Lethargy
  • Coma
  • Hypothermia
  • Decreased pupillary light reflex
  • Nystagmus
  • Strabismus
  • Vertigo
  • Slurred speech
  • Ataxia
  • Decreased deep tendon reflexes

Psychiatric manifestations may include the following:

  • Impairment in thinking (eg, memory disturbances, poor judgment, limited attention span); delirium of any kind is a cardinal feature
  • Irritability
  • Combativeness
  • Paranoia

Respiratory manifestations may include the following:

  • Respiratory depression
  • Apnea
  • Hypoxia
  • Acute respiratory distress syndrome

Cardiovascular manifestations may include the following:

  • Tachycardia
  • Bradycardia
  • Hypotension
  • Diaphoresis
  • Shock

Other manifestations may include the following:

  • Severe electrolyte and endocrine disturbances
  • Renal dysfunction
  • Gastrointestinal - Decreased bowel sounds
  • Skin - Barbiturate blisters (ie, bullous lesions typically found on the hands, buttocks, and knees)