Effect of volume of water taken with diazepam tablets on absorption

Thirty-three patients received either 10 ml (group A) or 50 ml (group B) of water with diazepam tablets as premedication while in the supine position. Plasma diazepam concentrations were measured, a delay in the attainment of the peak plasma concentration being taken as an indication of delayed absorption and oesophageal hold-up. There was no difference between the two groups, although in an important minority (16.7% (group A) and 20% (group B], absorption was delayed to beyond 60 min. There was a wide scatter of plasma diazepam concentrations in both groups. Dysphagia during swallowing did not appear to delay absorption.