STUDIES ON BARBITURATES XVII. THE EFFECT OF PROLONGED CHLOROFORM ANESTHESIA ON THE DURATION OF ACTION OF BARBITURATES

¹ From the Department of Pharmacology and Materia Medica, Georgetown University, School of Medicine, Washington, D. C.

Chloroform anesthesia of two hours duration prolongs the anesthetic actions of pentobarbital and barbital when these drugs are administered twenty-four hours later.

The previous exposure to chloroform also increases the depth of anesthesia and animals may die in the depressed state following the administration of one-half of the average fatal dose of barbiturates. The animals receiving barbital following chloroform anesthesia become narcotized almost immediately.

Chloroform treated animals show a greater retention of both pentobarbital and barbital in their blood and organs than do normal animals, and also show a lag in the urinary excretion of barbital.

An explanation is suggested for the above facts, viz., that chloroform aside from its hepatic effect and even though completely eliminated from the central nervous system, has sufficiently injured the cells of the central nervous system so that they are more susceptible to the action of barbiturates.