An Australian (1995) study found oxazepam less toxic and less sedative, and temazepam more toxic and more sedative, than most benzodiazepines in overdose. Temazepam was shown to be more toxic than the majority of benzodiazepines. Over 10 years in the United Kingdom, 1512 fatal poisonings have been attributed to benzodiazepines with or without alcohol. Benzodiazepines are one of the most highly prescribed classes of drugs, and they are commonly used in self-poisoning. The US Food and Drug Administration (FDA) has subsequently issued a black box warning regarding concurrent use of benzodiazepines and opioids. In 2013, benzodiazepines were involved in 31% of the estimated 22,767 deaths from prescription drug overdose in the United States. However, combinations of high doses of benzodiazepines with alcohol, barbiturates, opioids or tricyclic antidepressants are particularly dangerous, and may lead to severe complications such as coma or death. The most common symptoms of overdose include central nervous system depression and intoxication with impaired balance, ataxia, and slurred speech.

Deaths from single-drug benzodiazepine overdoses occur infrequently, particularly after the point of hospital admission. Benzodiazepine overdose or toxicity is particularly dangerous, especially in combination with alcohol, barbiturates, opioids or tricyclic antidepressants.

Benzodiazepine toxicity antidote