THE EFFECT OF REPEATED ADMINISTRATION OF EPHEDRINE

¹ From the Laboratory of Pharmacology of Peking Union Medical College, Peking, China

1. Ephedrine administered either intravenously, intramuscularly or per os, to small white rabbits in doses of 25 milligrams, daily for four weeks except Sundays, does not produce any observable toxic effects.

2. The total amount of ephedrine given by intravenous injection was as great as 8 times the M.L.D. calculated for the initial body weight of the animal.

3. All of the animals, with few exceptions, show a large gain in body weight, after a period of about one hundred forty days.

4. The visceral organs from treated animals by gross and microscopic examination do not show any definite or uniform lesion that can be attributed to the effect of ephedrine.

5. No tolerance is developed in rabbits to the mydriadic or pressor action of ephedrine by repeated administration nor is there any change in the dose required to cause death.

6. In white rats, ephedrine given in doses of 100 mgm. per kilo every other day for seven days, does not produce any damage to the visceral organs which cannot be explained by other causes.