Of zinc, as a prophylactic tonic in cardiac neuralgia, I know but little. Truth to say, it is a nervine tonic of occasional great value, but which, on the whole, I have found so unreliable that I am somewhat prejudiced against it; and perhaps have not given it a fair trial in those milder cases of cardiac pain to which it might be suited. It does appear, however, to have some preferential action on the vagus, and might therefore be possibly more useful than I am at present inclined to think it.
The treatment of the acute neuralgic stage itself is a matter in which we are sadly limited by the exigencies of the case. Relief must be excessively rapid if we are to save life in the most threatening cases, or to deliver the patient from a most prostrating agony, which might have lasted for hours, in other instances.
The remedy which the highest authority, Dr. Walshe, seems to put first in efficacy is opium; and he directs the dose to be measured by the intensity of the pain, as much as forty to sixty drops of laudanum being given in a severe case. He says, however, that it should be given with an antispasmodic, such as brandy, or ether, or sal-volatile; and I confess that I believe the antispasmodic treatment to be by far the most important. Indeed, so marked is the success which I have found to attend the use of ether in the paroxysm, that till lately I scarcely cared to make further experiments, with drugs, for the relief of the patient at this stage. One teaspoonful of ether in two ounces of thickish mucilage should be given at once, and repeated in a short time if the patient does not rally.
In a few instances, angina seems to be provoked by the irritation of indigestible food, and when there is good reason to suspect this an emetic should be given. I strongly recommend that mustard should be used for this purpose, for the effect of a mustard-emetic is by no means merely to empty the stomach, it has a powerfully rousing influence on the heart.
Upon the subject of the inhalation of chloroform for cardiac neuralgia, I have only to say that, though I have seen it usefully employed, I should not, with my present experience, ever think of employing it myself. Every possible advantage which it could give is obtained by the internal use of ether, and many serious dangers are avoided, which would attend the use of chloroform. For it must be remembered that the only kind of chloroform inhalation which would be useful would be that in which a carefully measured small dose of a weakly impregnated atmosphere should be inhaled, and, without large experience in the administration of chloroform, the practitioner will be unable to secure this effect with certainty. And the effect of a powerfully-charged atmosphere, breathed only once or twice even, would be instantaneously fatal.