A barbiturate overdose results when a person takes a larger-than-prescribed dose of barbiturates. Symptoms of an overdose typically include sluggishness, incoordination, difficulty in thinking, slowness of speech, faulty judgment, drowsiness, shallow breathing, and staggering. In severe cases, coma and death can result. The lethal dosage of barbiturates varies greatly with tolerance and from one individual to another.
Barbiturate overdose with other CNS (central nervous system) depressants, such as alcohol, opiates or benzodiazepines, is even more dangerous due to additive CNS and respiratory depressant effects. In the case of benzodiazepines, barbiturates also increase the binding affinity of the benzodiazepine binding sites thus leading to an exaggerated effect of benzodiazepines.
The treatment of barbiturate abuse or overdose is generally supportive. The amount of support required depends on the person's symptoms. If the patient is drowsy but awake and can swallow and breathe without difficulty, the treatment can be as simple as monitoring the patient closely. If the patient is not breathing, it may involve mechanical ventilation until the drug has worn off.
Supportive treatment often includes the following:
Activated charcoal may be given via nasogastric tube.