METABOLIC AND SUBJECTIVE RESPONSES TO ORAL DIAZEPAM AND MIDAZOLAM

Diazepam premedication decreases the overall metabolic rate and oxygen consumption. Whether its properties are shared by midazolam is not kn own. In this study, eight healthy male volunteers were given oral diaz epam (10 mg), midazolam (15 mg) and placebo in a random double-blind c ross-over fashion. Metabolic responses were measured using an indirect calorimetry device. Subjective responses were measured using a visual analogue scale. Plasma concentrations of diazepam, midazolam and desm ethyldiazepam were analysed and correlated to changes in metabolic and subjective responses. When compared to placebo, both diazepam and mid azolam significantly decreased oxygen consumption (P<0.01 in pairwise comparisons) and energy expenditure (P<0.01 in pairwise comparisons). While there was a significant correlation between the plasma concentra tions of diazepam and the changes in metabolic parameters, no such cor relation was found with midazolam. Both diazepam and midazolam were su bjectively more sedative than placebo (P<0.05). There was no significa nt difference between the sedative effect of diazepam and midazolam, b ut diazepam was subjectively better tolerated than midazolam. These re sults indicate that both diazepam and midazolam, in addition to their CNS effects, significantly decrease the overall metabolic rate and oxy gen consumption in healthy volunteers.