Respiratory Depression Following Diazepam

Abstract

The effects of naloxone and saline solution on the respiratory changes following diazepam in a double-blind corssover trial in 6 subjects were compared. Following baseline measurements of respiration, each subject was given diazepam, 15 mg, i.v. Sixty and 95 min later each subject received 2 doses of naxolone, 15 mg i.v., or 2 doses of the equivalent volume of saline solution. Forty-five minutes after diazepam administration the slopes of the curves of the ventilatory responses to rebreathing CO2 (.ovrhdot.VE/PETCO2; ventilation/end-tidal CO2 tension) were depressed to 53% of control (P < 0.05). Following the 2 doses of naloxone, the slopes of .ovrhdot.VE/PETCO2 recovered, until, 120 min after the 2nd dose of naloxone, slopes had returned to control values. After saline solution slopes remained depresses at 68% of control (P < 0.05). A similar recovery following naloxone was observed in the PETCO2 intercept of the .ovrhdot.VE/PETCO2 response curve and in the slope of the mouth-occlusion-pressure response curve to rebreathing CO2. End-tidal CO2 during quiet breathing and during inspiratory resistive-loaded breathing (80 cm H2O/l per s) showed small increases after diazepam, which were not significantly reduced by naloxone. Diazepam produces respiratory depression and this may be relieved by large doses of naloxone.