Midazolam IV is the first benzodiazepine that was produced primarily for use in anaesthesia. Walser and colleagues in 1976 “first described midazolam, the first clinically used water-soluble benzodiazepine.
The imidazole ring in its structure accounts for its stability in aqueous solution and rapid metabolism. It is two to three times as potent as diazepam and has an affinity twice that of diazepam to benzodiazepine receptors.
Midazolam IV a water-soluble benzodiazepine midazolam is the most frequently used intravenously because of its rapid onset and offset and lack of active metabolites compared with other benzodiazepines (e.g., diazepam).
The onset of midazolam IV is slower than that of propofol and barbiturates, and its offset, especially when used at higher doses or in a prolonged infusion, is considerably longer than that of propofol or methohexital.
The benzodiazepines act through the GABA receptor. Flumazenil is a specific benzodiazepine antagonist. It can be used to reverse the effects of benzodiazepines.
The benzodiazepines generally produce only a mild decrease in blood pressure and mild-to-moderate respiratory depression. The dose of midazolam IV for anxiolysis and mild sedation is 0.015 to 0.03 mg/kg intravenously and is generally repeated in 30 to 60 minutes as needed.
Midazolam IV has a slow time to peak effect, and repeat bolus doses should be spaced at least 3 to 5 minutes apart to avoid inadvertent overdosing.
At plasma concentrations of 40 ng/mL of midazolam IV , humans are able to encode and retain memories over a period of 15 to 30 minutes. However, these memories are lost before consolidation.