A determination of possible deliberate overdose should be considered with appropriate scrutiny, and precautions taken to prevent any attempt by the patient to commit further bodily harm. Hypotension is corrected with fluid replacement, although catecholamines such as norepinephrine or dopamine may be required to increase blood pressure. Bradycardia is treated with atropine or an infusion of norepinephrine to increase coronary blood flow and heart rate. Flumazenil
Flumazenil (Romazicon) is a competitive benzodiazepine receptor antagonist that can be used as an antidote for benzodiazepine overdose. Its use, however, is controversial as it has numerous contraindications. It is contraindicated in patients who are on long-term benzodiazepines, those who have ingested a substance that lowers the seizure threshold, or in patients who have tachycardia, widened QRS complex on ECG, anticholinergic signs, or a history of seizures. Due to these contraindications and the possibility of it causing severe adverse effects including seizures, adverse cardiac effects, and death, in the majority of cases there is no indication for the use of flumazenil in the management of benzodiazepine overdose as the risks in general outweigh any potential benefit of administration. It also has no role in the management of unknown overdoses. In addition, if full airway protection has been achieved, a good outcome is expected, and therefore flumazenil administration is unlikely to be required.Flumazenil is very effective at reversing the CNS depression associated with benzodiazepines but is less effective at reversing respiratory depression. One study found that only 10% of the patient population presenting with a benzodiazepine overdose are suitable candidates for flumazenil.
In this select population who are naive to and overdose solely on a benzodiazepine, it can be considered. Due to its short half life, the duration of action of flumazenil is usually less than 1 hour, and multiple doses may be needed. When flumazenil is indicated the risks can be reduced or avoided by slow dose titration of flumazenil. Due to risks and its many contraindications, flumazenil should be administered only after discussion with a medical toxicologist. Epidemiology
In a Swedish (2003) study benzodiazepines were implicated in 39% of suicides by drug poisoning in the elderly 1992–1996. Nitrazepam and flunitrazepam accounted for 90% of benzodiazepine implicated suicides. In cases where benzodiazepines contributed to death, but were not the sole cause, drowning, typically in the bath, was a common method used. Benzodiazepines were the predominant drug class in suicides in this review of Swedish death certificates. In 72% of the cases, benzodiazepines were the only drug consumed. Thus, many of deaths associated with benzodiazepine overdoses may not be a direct result of the toxic effects but either due to being combined with other drugs or used as a tool to kill oneself using a different method, e.g. drowning.In a Swedish retrospective study of deaths of 1987, in 159 of 1587 autopsy cases benzodiazepines were found. In 44 of these cases the cause of death was natural causes or unclear. The remaining 115 deaths were due to accidents (N = 16), suicide (N = 60), drug addiction (N = 29) or alcoholism (N = 10).