Antipyretic Action of Magnesium Chlorid Alone and Combined With Amidopyrin.

Abstract

The temperature reducing properties of magnesium salts in doses below the threshold for the well known Meltzer narcosis, have been described by J. Schütz, 1 for normal rabbits. Rabbits artificially fevered with β-tetra-hydro-naphthylamin also exhibited antipyresis with magnesium. The latter, however, has apparently never been investigated hitherto with regard to the reduction of fever of bacterial origin. In animals with hay-infusion fever, it is not difficult to demonstrate a marked antipyretic action with doses of magnesium salts far below the toxic range. This can be especially well shown with magnesium chlorid in rabbits previously injected with hay-infusion incubated 48 hours, at 37° C.

Healthy adult rabbits after fasting over night were injected subcutaneously with 1 cc. (per kilo) hay-infusion. A rise in temperature amounting to at least 1.5° F. was found within about 2 hours, in approximately two-thirds of the injected rabbits. The antipyretic agent was injected subcutaneously, usually 2 to 3 hours after the fever injection; at least 2 well fevered rabbits were retained for controls.

In the present work MgCl₂ was used in 5% solution, amidopyrin in 4% solution. When “combined” the same solutions were used, one immediately following the other; whether injected at the same or different sites was found immaterial.

The results as shown in the curves (Figs. 1 and 2) represent differences in body temperature between treated animals and untreated fever controls, the zero temperature being the temperature at the time (zero hour) of giving the magnesium chlorid.

To produce definite magnesium antipyresis in hay-infusion fever rabbits, about 200 mg.∗ of the chlorid per kilo are required, as illustrated in Fig. 1, which shows the effect of 12 injections varying from 150 to 300 mg. per kilo. The difference between the fever control curves and those resulting from 150 mg. per kilo magnesium chlorid represents approximately the maximum variation to be expected with inadequate doses.