Effect of flumazenil on benzodiazepine-induced respiratory depression

The ability of flumazenil to reverse benzodiazepine-induced respiratory depression is discussed through a review of the relevant literature. Flumazenil has been shown to be effective in reversing benzodiazepine-induced sedation, but its ability to reverse benzodiazepine-induced respiratory depression is controversial. Part of this controversy stems from the lack of consistent data on the incidence and nature of depressed respiratory function after benzodiazepine administration. In addition, a variety of tests are used to assess respiratory function, but because breathing is both automatic and under voluntary control, the results of some of these tests can be affected by patient effort. In such cases, improvement can result from an increased level of consciousness even though the central respiratory drive remains depressed. Thus, studies using these tests to determine flumazenil's effect on respiratory depression are inconclusive, as they do not accurately measure reversal of the central respiratory depression induced by benzodiazepines. However, studies using methods that do accurately assess central respiratory drive have involved small numbers of subjects and demonstrated a variable incidence of respiratory depression associated with benzodiazepine use. When benzodiazepine-induced respiratory depression was evident, the ability of flumazenil to reverse it was inconsistent and short-lived. Flumazenil may be able to improve breathing through improved consciousness, but its effects on central respiratory depression are inconsistent. Therefore, unless additional information becomes available supporting flumazenil's ability to reverse benzodiazepine-induced respiratory depression, it should not be used for this indication.