Efficacy of propofol compared to midazolam as an intravenous premedication agent

It is common practice to administer a premedication to patients about to undergo anesthesia. This study compared the effects of a small intravenous bolus of propofol versus midazolam administered as a premedication.

In this prospective, randomized, double-blind, placebo-controlled study, 60 healthy adult subjects scheduled for general anesthesia were given midazolam (0.04 mg/kg), propofol (0.4 mg/kg) or saline intravenously in the anesthesia waiting room. Before administration and three times at 2.5 min intervals subsequently, blood pressure, heart rate, oxygen saturation and scores for anxiety and dizziness were recorded. Recall of words and images shown to the patient 5 min after drug administration was tested 10-30 min after recovery from anesthesia.

Both propofol and midazolam helped relieve anxiety and lowered blood pressure (P<0.001, compared to baseline), but both were associated with greater dizziness scores (P<0.001, compared to placebo). Compared to placebo and propofol, midazolam was associated with more frequent respiratory depression (P<0.05) and significant impairment of anterograde explicit memory (P<0.05).

Propofol may be an economical and safe alternative to midazolam for i.v. premedication.