Intranasal midazolam plasma concentration profile and its effect on anxiety associated with dental procedures

The objectives of this study were to describe the serum concentration time profile for midazolam following intranasal administration to adult dental surgery patients and to ascertain the effect of midazolam on anxiety. Six female patients received a single 20 mg (0.32 to 0.53 mg/kg) dose of midazolam. Blood samples were collected at 5, 10, 20, 30, 45, and 60 min following dose administration. Midazolam plasma concentrations were determined by gas chromatography. Anxiety was evaluated using a 100-mm visual analogue scale. The maximum concentration of midazolam was reached 25.8 min (range 18 to 35 min) following dose administration. Maximum concentrations were variable. However, there was no relationship between the weight-adjusted dose and maximal concentration. Patients experiencing baseline anxiety exhibited a trend toward reduction in their measured anxiety score (P = 0.06). Plasma concentrations above the hypothesized minimum effective concentration for sedative effects were attained when midazolam was administered intranasally to adult dental patients.