How many mg of midazolam is lethal


Midazolam (DORMICUM) was previously available as an intravenous form of application for induction of anesthesia and for short-term anesthesia during endoscopic or diagnostic interventions. In comparison with other representatives of this group of substances, the benzodiazepine stands out due to its inhibition of the respiratory center similar to that of barbiturates. According to the increased responsiveness of the CNS of older people to the substance, it must be dosed according to the patient and reduced to a quarter of the standard dose according to age.1

Nonetheless, deaths occur again and again. Even with an adequate dose, patients can be addressed quickly after anesthesia, but due to an imperceptible persistent respiratory depression after being transferred back to the ward, they may develop into hypoxia. The US health authority estimates that this causes 40 to 60 deaths annually in the USA, which could be avoided if endoscopic examinations were carried out with diazepam (VALIUM et al.) And not with midazolam (cf. at 7 [1988], 67 ).2

Another risk of midazolam is an unpredictable extension of the duration of action in some patients, which leads to delayed awakening and the need for ventilation.3 The ability to perform mechanical ventilation is therefore one of the prerequisites when midazolam is used as a short-term anesthetic.

For these reasons, midazolam is to be rated as a potentially high-risk anesthetic, the use of which requires a precise assessment of the dosage. Now, according to the manufacturer's recommendation, premedication should also be carried out with the oral application form introduced in May 1990. The tablet contains 7.5 mg midazolam, about 60% of which should be bioavailable. If a patient is premedicated in this way one hour before anesthesia, the doctor will not know what dose the patient has already received when anesthesia is induced. The exact dose estimate is made impossible.

The tablet strength is too high for elderly patients. In such patients, a total dose of 2 to 2.5 mg i.v. is often sufficient. to induce anesthesia. The use of midazolam tablets for premedication is therefore likely to increase the risk of anesthesia and appears dangerous.

Premedication with the oral form of the respiratory-depressive midazolam cannot be justified because enough benzodiazepines are available without this risk and with sufficient sedative properties. If diazepam (VALIUM, etc.) and related substances are not used due to the long duration of action, there are sufficient alternatives available with lorazepam (TAVOR etc.), oxazepam (ADUMBRAN etc.) or flunitrazepam (ROHYPNOL) with an appropriate medium-long duration of action. Short-acting substances such as triazolam (HALCION) are less suitable because of psychological disturbance effects (anterograde amnesia, psychotic reactions, cf. a-t 5 [1990], 49).