From the Guidelines
Barbiturate overdose is a medical emergency that requires immediate treatment with supportive care, and in severe cases, extracorporeal treatment (ECTR) such as hemodialysis may be necessary to remove the drug from the bloodstream. The treatment of barbiturate overdose typically involves airway management, ventilation support, and fluid resuscitation [ 1 ]. Activated charcoal may be administered if the ingestion was recent (within 1-2 hours).
Key Considerations
- Barbiturates cause central nervous system depression by enhancing the inhibitory effects of GABA, leading to respiratory depression, hypotension, hypothermia, and coma [ 1 ].
- The antidote for barbiturate overdose is primarily supportive care, as flumazenil is not effective for barbiturate overdose [ 1 ].
- ECTR is indicated to treat long-acting barbiturate poisoning when any of the following conditions are met: prolonged coma is present or expected, shock is present after fluid resuscitation, despite MDAC treatment, toxicity persists, or respiratory depression necessitating mechanical ventilation is present [ 1 ].
Treatment Approach
- Optimal and full supportive care remains the mainstay of treatment in all cases of barbiturate poisoning [ 1 ].
- Intermittent HD is the preferred mode of ECTR of severe barbiturate poisoning, but intermittent hemoperfusion or continuous renal replacement modalities are valid alternatives if intermittent HD is not available [ 1 ].
- Cessation of ECTR should be based on clinical efficacy and response to barbiturate removal, rather than completing a specific duration of ECTR or reaching a specific drug concentration [ 1 ].
Prevention
- Prevention of barbiturate overdose includes proper medication storage, taking medications exactly as prescribed, and avoiding alcohol or other CNS depressants while using barbiturates.
From the FDA Drug Label
The toxic dose of barbiturates varies considerably. Barbiturate intoxication may be confused with alcoholism, bromide intoxication and various neurological disorders. For sedation, therapeutic blood levels of phenobarbital range from 5-40 µg/mL; the lethal blood level is greater than 80 µg/mL and usually ranges from 100-200 µg/mL Acute overdosage with barbiturates is manifested by CNS and respiratory depression which may progress to Cheyne-Stokes respiration, areflexia, constriction of the pupils to a slight degree (though in severe poisoning, they may show paralytic dilation), oliguria, tachycardia, hypotension, lowered body temperature and coma Treatment of overdosage is mainly supportive and consists of the following: Maintenance of an adequate airway, with assisted respiration and oxygen administration as necessary. Monitoring of vital signs and fluid balance Fluid therapy and other standard treatment for shock, if needed. If renal function is normal, forced diuresis may aid in the elimination of the barbiturate. Alkalinization of the urine increases renal excretion of phenobarbital.
Barbiturate Overdose Management:
- The treatment of barbiturate overdose is mainly supportive.
- Key interventions include:
- Maintenance of an adequate airway
- Assisted respiration and oxygen administration as necessary
- Monitoring of vital signs and fluid balance
- Fluid therapy and standard treatment for shock if needed
- Forced diuresis and alkalinization of the urine may aid in the elimination of the barbiturate if renal function is normal.
- Hemodialysis may be used in severe cases or if the patient is anuric or in shock 2.
From the Research
Treatment Options for Barbiturate Overdose
- Activated charcoal is a commonly used treatment for barbiturate overdose, as it can help reduce the absorption of the drug and increase its elimination from the body 3, 4, 5, 6.
- Studies have shown that multiple doses of activated charcoal can be effective in shortening the elimination half-life of phenobarbital and reducing the duration of coma in patients with barbiturate overdose 3, 4, 5, 6.
- Urinary alkalinization is another treatment option for barbiturate overdose, but studies have shown that multiple-dose activated charcoal may be more effective in enhancing phenobarbital elimination 5.
- In severe cases of barbiturate overdose, hemodialysis and hemoperfusion may be used to enhance drug clearance 7.
Efficacy of Treatment Options
- A study comparing the efficacy of multiple-dose activated charcoal and urinary alkalinization found that multiple-dose charcoal was superior in enhancing phenobarbital elimination 5.
- Another study found that repeated doses of activated charcoal significantly increased the elimination of phenobarbital, but had no clear effects on the patients' clinical course 6.
- A study of six patients with moderate to severe phenobarbitone intoxication found that treatment with repeated oral doses of activated charcoal resulted in rapid recovery and a significant reduction in plasma phenobarbitone concentrations 4.