1. CARDIAC TONICS.-Digitalis: There is no drug that can take the place of digitalis in loss of compensation in chronic valvular disease. It acts specifically for good, and it has its greatest success in the valvular lesions that cause enlargement of the left ventricle, on which it acts the most intensely. It also acts for good on the right ventricle. It has but little action on the auricles. This is simply a question of muscle; the part that has the greatest amount of muscle will receive the greatest benefit from digitalis, and the parts that have the least, the least benefit. The heart muscle is somewhat similar to other muscles; when we attempt athletic improvement in any muscle of the body, we "train" by stimulating it moderately at first, and are careful not to overwork it; the object, then, is to train the heart muscle. For this reason large doses of digitalis should ordinarily not be given to overstimulate suddenly an overworked and weak heart. While in some instances it has been declared that digitalis should be rapidly pushed to the full extent and then dropped for a time, careful experience shows that this method is often not tolerated, sometimes does positive harm, and has at times seemed to hasten death.

Another valuable activity of digitalis is in slowing the heart by action on the pneumogastric nerves. A dilated heart has lost more or less of its regulating mechanism; this is the cause of its irregularity and its increased rapidity. The action of digitalis in slowing the heart, giving it a longer rest, and preventing it from acting irregularly is of great value. This prolonged rest or diastole of the heart allows the circulation in the coronary arteries to become normal, and the nutrition and muscle tone of the heart improves. Digitalis also increases the blood pressure, not only by improving the activity of the heart, but also by causing some contraction of the arterioles. This feature of digitalis action in arteriosclerosis renders its use sometimes a question of careful decision. The dose of digitalis under such a condition should not be large. It may be indicated, however, and may do a great deal of good, and it does not always increase the blood pressure.

If the patient is sufficiently ill to require the best action of digitalis, an active preparation should be obtained. It was long supposed that the infusion presented activities which could not be furnished by the tincture of digitalis. This seems not to be true. The greater value of the infusion is generally because it is freshly made and active; the tincture which had been used previously in a given case was old and useless; furthermore, most physicians give a larger dose of the infusion than they ever do of the tincture. Owing to the uncertainty of the value of the digitalis leaves found in the various drug shops, however, and to variations in the preparation of the infusion, it is generally better to use a tincture of known character. The beginning dose of such a tincture should generally not be more than 5 drops, and it should not be repeated more frequently than once in eight hours. It is generally advisable, in two or three days, to increase this dose to 10 drops once in twelve hours, later perhaps to 15 drops twice a day, and still later to 20 drops once a day. This amount may then be decreased gradually, if the action is satisfactory. Enough should be given to procure results, and then the dose should be brought down to what seems sufficient and best, administered once a day. The frequence advised in the administration of this drug is because it is eliminated slowly. Its greatest action develops a number of hours after it has been taken, and then the action lasts for many hours; the administration of digitalis once in twenty-four hours is perfectly satisfactory for many patients, and more satisfactory than any more frequent administration. On the other hand, some patients do better on a smaller dose once in twelve hours. This frequence is always sufficient.

Digipuratum and digitol, a fat-free tincture, proprietary preparations accepted by the Council on Pharmacy and Chemistry for inclusion in N. N. R., may be employed. They are standardized preparations and may thus be more satisfactory than some pharmacopeial preparations of digitalis, although their claims to lessened emetic action are not borne out by recent experiments of Hatcher and Eggleston.

Digipuratum may be obtained in tubes of twelve tablets. The advice has been given for patients with loss of compensation to receive four tablets the first day, three the second, three the third, and two the fourth day. This, however, is generally an overdosage. The most that should generally be given is one of these tablets in twelve hours. Digipuratum fluid is also a valuable preparation.

Digitol is a fat-free tincture of digitalis which is physiologically standardized and which bears on each package the date of manufacture. The close is from 0.3 to 1 c.c. (5 to 15 mimims).

Digitalinum, one of the active principles of digitalis, is not very satisfactory. It may be given hypodermically, but often causes irritation, and the proper dose and its value are apt to be uncertain.

Digitoxin, another active principle of digitalis, has been declared by some investigators to be harmful, also to be liable to cause serious disturbance of a damaged heart. Other investigators have stated that it acts for good. Digitoxin does not represent the whole value of digitalis, and in broken compensation digitalis itself, or some preparation embodying the majority of its activities, should be given. Digitoxin, however, is often valuable in conditions of cardiac debility or slight weakening in patients who do not have dilated hearts or edemas. The most satisfactory dose of digalen is from 5 to 10 drops once or twice in twenty-four hours.

Tags: Heart Disease