Thiopental anesthesia and tannic acid diagnostic enemas.

The administration to albino rats of tannic acid as a retention enema (in doses of 0.2 g./kg. body weight and over) prolonged the duration of anesthesia induced by thiopental given immediately before, or 72 hours after, the tannic acid. This dose of tannic acid corresponds, on the basis of body weight, to a radiodiagnostic enema of 2 1. of 0.25% tannic acid in barium sulfate suspension given to a child weighing 25 kg. By excluding certain hypothermic effects of tannic acid, it was concluded that thiopental potentiation was probably due to impairment by the tannic acid of the liver's ability to detoxify the barbiturate. The results suggest that a drug which is detoxified in the liver should be administered three to five days after a tannic acid-barium sulfate radiodiagnostic enema only with considerable caution.