For premedication, the recommended midazolam dosage is 0.07 to 0.08 mg/kg IM (usual dose is about 5 mg IM for an average adult) administered 30 to 60 minutes preoperatively.
Lower doses should be used in elderly or debilitated patients. In a study of patients 60 years or older who did not receive concomitant narcotics, 2 to 3 mg of midazolam dosage produced adequate sedation during the preoperative period.
Some patients responded to doses as low as 1 mg. As with any potential respiratory depressant, these patients require observation for signs of cardiorespiratory depression after receiving IM midazolam dosage .
Onset of action is within 15 minutes, with peak effect occurring 30 to 60 minutes following injection. When administered concomitantly with a narcotic, the dose of midazolam should be reduced.