Chinese Journal of Physiology

COMPARATIVE TOXICITY OF EPHEDRINES

FROG 3 LYMPH SAC 100 30 BO 70 60 50 40 uss 30 H - } = H =hoa 20 a = — Fo. & ot ui Gq uD =H fi oi io F 6 Le RABBIT, gray 2 SUBCUTANEOUS 100 4 pe

30

[EPHETONN ni

| Ps-EPHEDRINE

RAT RABBIT, grag SUBCUTANEOUS INTRAVENOUS

aR Fi x

;

H i H H E

f°s-EPHEDRINE PePuEDRINE

—

RABBIT, white BOG

INTRAVENOUS

|

IP S-EPHEDRINE

EPHEDRINE l EPHETONIN

Fig. 1. Comparative magnitudes of M.L.D. of ephedrine, ephetonin and pseudoephedrine in different animals by different methods of administration.

It should also be noted that our work was done in June at a temperature of 27.5 to 31°C. A short series performed in the late autumn gave a slightly lower figure for ephedrine but it required fifteen per cent more of pseudoephedrine to kill the animals. Another series

was conducted in very hot, damp summer weather.

87

In all cases the

lethal dose was smaller by eight to nineteen per cent 500, 590 and 650 mg for ephedrine, ephetonin and pseudoephedrine as compared with 540,630 and 770 mg required under more normal conditions.

which is more musculotropic than ephedrine.

It seems as if temperature had an influence, especially upon pseudoephedrine