Adsorption of Diazepam to Plastic Tubing

To the Editor: Diazepam has become one of the mainstays of therapy for convulsions, anxiety and preoperative and postoperative anesthesia.¹ We have recently observed extensive adsorption of diazepam to plastic tubing during continuous infusion. Plasma concentrations of diazepam after such infusions are therefore much lower than predicted. A multiple-infusion regimen, designed to rapidly attain and maintain plasma concentrations of diazepam at 400 to 500 ng per milliliter, was tested in a 15-month-old girl (10.5 kg) with recurrent seizures who had become unresponsive to her usual anticonvulsant regimen. Diazepam (Roche Laboratories, Nutley, New Jersey) was diluted in glass containers of sterile.