Toxicity
Benzodiazepines have a wide therapeutic index and taken alone in overdose rarely cause severe complications or fatalities. They are, however, not devoid of serious toxicity and cases of severe coma or fatality have been reported. Taken in overdose in combination with alcohol, barbiturates, opioids, tricyclic antidepressants, or sedating antipsychotics, anticonvulsants, or antihistamines are particularly dangerous. In the case of alcohol and barbiturates, not only do they have an additive effect but they also increase the binding affinity of benzodiazepines to the benzodiazepine binding site, which results in a very significant potentiation of the CNS and respiratory depressant effects. In addition, the elderly and those with chronic illnesses are much more vulnerable to lethal overdose with benzodiazepines. Fatal overdoses can occur at relatively low doses in these individuals.
Read more about this topic: Benzodiazepine Overdose