Some pharmacological factors influencing the absorption of diazepam following oral administration.

Plasma diazepam concentrations were measured by gas-liquid chromatography in samples of blood from adult female patients follwing diazepam 10 mg orally, alone or in combination with metoclopramide, morphine, pethidine or atropine. Patients receiving metoclopramide had higher plasma diazepam concentrations than those in the control group, while the addition of morphine, pethidine or atropine resulted in lower plasma diazepam concentrations throughout the 90-min period of the study. In the control goup peak plasma concentrations were reached by 60 min. The addition of metoclopramide increased the rate of diazepam absorption and peak concentrations were reached by 30 min, while morphine, pethidine and atropine reduced the rate of absorption with no apparent peak being reached by 90 min.