Management overview for barbiturate poisoning

Barbiturates are sedative and antiepileptic drugs. Barbiturates available in Australia include phenobarbital (phenobarbitone), pentobarbital, primidone and thiopental.

Barbiturate poisoning is uncommon but hazardous, because these drugs have a narrow therapeutic index and cause dose-dependent sedation. The degree of toxicity depends on the individual’s tolerance to the drug. Significant poisoning with long-acting barbiturates (phenobarbital, primidone) can result in prolonged central nervous system (CNS) depression. Pentobarbital is a medium-acting barbiturate that is used in animals; it can also cause prolonged CNS depression.

Management priorities include supportive care with early intubation and ventilation. In large ingestions of long-acting barbiturates, consider multiple-dose activated charcoal and, if there is haemodynamic compromise, extracorporeal elimination. Consult with a clinical toxicologist regarding these therapies.