The absorption of digitalis from the rectum in man.

Abstract

Not infrequently, patients suffering from heart failure are unable to take digitalis by mouth because of nausea, vomiting or surgical operation. The margin of safety between therapeutic and toxic dose, when a member of the digitalis group is given by vein, is sufficiently small to render this method of administration hazardous. The present study was undertaken to ascertain the feasibility of rectal digitalis therapy, concerning which only a few fragmentary reports have been recorded.

Twenty-six observations were made on 20 patients with auricular fibrillation. Hourly records of heart and pulse rates were charted for 8 hours after the drug was given and at 4 hour intervals for the next 24 hours. In 19 instances, an electrocardiogram was taken just before administration and approximately every hour thereafter for 3, 4, or 5 hours. Another graphic record was made the following morning.

The preparation employed was an aqueous extract of digitalis leaves furnished by Merck and Company and called by them “Digitan.” One cubic centimeter of the liquid contained the equivalent of 0.1 gm. of powdered leaf. Biologic assay was done by the 1 hour frog method.

The patient received a preliminary cleansing enema. After evacuation, 8 to 20 cc. of digitan were given by rectal tube and washed through with 25 cc. of water. The micro-enema was retained. Alcoholic extracts of digitalis were found to be irritating to the rectal mucosa unless diluted to such volume that, because of bulk, they were often expelled.

Retardation in ventricular rate occurred in every instance following digitalis administration. The average time necessary for an unmistakable initial effect on rate was 2 hours and 35 minutes. The interval ranged from 1 hour and 15 minutes to 7 hours and 40 minutes.