STUDIES ON THE PHARMACOLOGY OF METAPHEN AND ACRIFLAVINE

¹ From the Department of Physiology and Pharmacology, Northwestern University Medical School

Metaphen intravenously, except in enormous doses, does not have any effect on the blood pressure, heart rate and respiration of either barbitalized or unanesthetized dogs. In general, intravenous injection of therapeutic doses (0.15 mgm. per kilogram) cause a marked leucocytosis, accompanied by a proportional increase in the different forms of leucocytes. In 1 dog out of ten a leucopenia resulted. It has no effect in similar doses on the fragility of erythrocytes. The minimum lethal dose of metaphen in dogs is 3.5 mgm. per kilogram, which on the basis of its mercury content is equivalent to the minimum lethal dose of bichloride of mercury.

Certain preparations of acriflavine are definitely toxic, causing marked changes in the heart rate, circulation, and respiration, and nausea and vomiting in intravenous doses of from 2 to 5 mgm. per kilogram. A neutral preparation of acriflavine can be prepared which in doses of from 1 to 2 mgm. per kilogram causes either no or only slight changes in heart rate, respiration and blood pressure. Preparatinns of acriflavine should be tested on unanesthetized animals before they are used for intravenous therapy. Even the least toxic preparations of acriflavine in small doses stimulate and in larger doses depress the peripheral vagal mechanism in the heart. Our results indicate that the chief point of action of acriflavine on the blood pressure is pheripheral.