Central nervous system depression or CNS depression refers to physiological depression of the central nervous system that can result in decreased rate of breathing, decreased heart rate, and loss of consciousness possibly leading to coma or death. CNS depression often results from the use of depressant drugs such as alcohol, opioids, barbiturates, benzodiazepines, general anesthetics, and anticonvulsants such as valproate semisodium used to treat epilepsy. Drug overdose is often caused by combining two or more depressant drugs, although overdose is certainly possible by consuming a large dose of one depressant drug. CNS depression can also be caused by the accidental or intentional inhaling of certain volatile chemicals such as Butanone (contained in Plastic Cement).
CNS depression is treated within a hospital setting by maintaining breathing and circulation. Individuals with reduced breathing may be given supplemental oxygen, while individuals who are not breathing can be ventilated with bag valve mask ventilation or by mechanical ventilation with a respirator. Sympathomimetic drugs may be used to attempt to stimulate cardiac output in order to maintain circulation. CNS Depression caused by certain drugs may respond to treatment with an antidote.