The effect of repeated administration of ephedrine.

Abstract

In our preliminary report, 1 the results from a rabbit with daily injections of 20 mg. of ephedrine per kilo intravenously for nine days were mentioned. Our present paper deals with a study of the same nature, but much more extensively.

Three series of young, healthy rabbits were selected for experimentation. One series of ten was given intravenous injections of 25 mg. of ephedrine sulphate, irrespective of their body weight, daily for four weeks except Sundays. The total dose amounted to as high as 8.172 times the M. L. D. with reference to the initial body weight, or 817.2 per cent of the M. L. D. Another series of ten was given daily intramuscular injections of 25 mg. of ephedrine sulphate for four weeks except Sundays. Still another series of ten was administered orally 25 mg. of the drug for the same length of time. The total dose in the former exceeded a little the intramuscular M. L. D., while that in the latter was slightly below the oral M. L. D. In all cases with one exception, the body weight was increased, and some animals gained as much as 61 per cent of the initial body weight. Practically all of them were kept alive for about 140 days, and then sacrificed.

Locally, in the intravenous injection, there was development of thrombosis which was gradually absorbed. In the intramuscular administration there was fibrosis at the site of injection, which also disappeared in course of time, for at the end of experiment it was impossible to locate the point of injection. When given by mouth ephedrine did not produce any detectable lesion in the gastro-intestinal tract that could be seen in the postmortem examination.