Doses given to children must be calculated on a mg/kg basis. Its half-life in children over 12 months is reported to be 0.8 to 1.8 hours, with a clearance of 4.7 to 19.7 ml/min/kg. Midazolam is excreted primarily by the kidney. The latter is conjugated to the glucuronide form, and it has only minimal biological activity.

It is metabolised in the liver by the cytochrome P450 system, and its chief metabolite is 1-hydroxymethyl midazolam.

It is water soluble in the commercially prepared formulation but becomes lipid soluble at physiological pH and can then cross the blood brain barrier. The most serious adverse events associated with midazolam in children include hypoventilation, decreased oxygen saturation, apnoea and hypotension. Midazolam has a faster onset and shorter duration of action than other benzodiazepines such as diazepam and lorazepam. The drug exerts its clinical effect by binding to a receptor complex which facilitates the action of the inhibitory neurotransmitter gamma-aminobutyric acid (GABA). Midazolam is a parenteral benzodiazepine with sedative, amnesic, anxiolytic, muscle relaxant and anticonvulsant properties.

Antidote midazolam