MYXEDEMA.
Thyroid feeding is the specific for this condition.
The only difficulty to be met with is the problem of dosage, since it is impossible at first to determine whether any portion of the gland is still functioning. Murray has shown that in ordinary routine practice ro mins. of the old B.P. Liquor Thyroidei daily for 6 out of the 7 days. in every week constitute a sufficient amount for most cases, once the signs and symptoms have been combated by larger or smaller doses. This dosage of i dr. per week may therefore be taken as a good practical guide to the amount necessary to maintain a healthy standard of metabolism during the remaining life of the myxcedematous subject, though in rare cases double this quantity may be necessary.
2 grs. Dry Thyroid are accepted as equivalent to ro mins. of the liquor by Murray, so that the ultimate weekly dosage of the drug in the tablet form should be about ro grs. Tt is necessary to point out that the liquor should not be used if more than a month or six weeks old, though the dried 13.P. powder will keep for long periods if preserved in stoppered bottles.
It does not yet appear that any of the numerous preparations made from the gland, as Iodothyrine or Thyro-iodin, Thyroglandin, Thyrocol, &c., are in any way superior to the official preparation. Kendall has isolated the pure alpha-iodine compound in crystalline form which promises to be an advance.
As soon as a case of myxcedema presents itself to the physician, thyroid feeding should be commenced without waiting for any preliminaries. If degenerative changes have occurred in the cardiac muscular fibre, the patient should be ordered to bed or to rest upon a sofa. The only danger lies in the over-anxiety of the physician to make a too rapid impression upon the abnormal metabolism; every case is one to which the maxim " Hasten slowly " is applicable. The best plan of procedure in advanced cases is to giver min. of the liquor after each meal thrice daily for about a week, then 2 mins. twice daily for the next week, after which 5, 6, or 7 mins. may be given at bed-hour only; the patient in about 6 or 8 weeks should be getting to mins. nightly. If the dried thyroid be used, ro to 12 grs. weekly meet
the requirements in most cases.
The pulse-rate increases under full doses, and any very marked elevation is a clear indication that the dosage should be reduced. In a similar manner the employment of the drug may be regulated by periodically weighing the patient, any rapid loss of weight being taken as proof that the thyroid feeding is exercising a too active influence over the body metabolism. When the amount is much beyond the needs of the patient it is a common occurrence for the body-temperature to rise above the normal, and the steady advance from the subnormal to the healthy temperature is a fair indication that the treatment is pursuing a satisfac tory course. In over-dosage, symptoms of exophthalinic goitre develop and should be always watched for.
The heart should be watched; any tendency towards syncope or dyspncea upon exertion should he met by restriction of exercise or absolute rest for a time and a reduction of the dose. Active exertion should be prohibited during the first few months of treatment, though mild cases may be permitted to pursue their ordinary avocations.
As the skin becomes moist, the solid cedcma passes away, the intellect brightens, and thought power becomes more active, the physiognomy changes and the myxcedematous patient, like the cretin, emerges from a lower to a higher plane of existence. The hair, as a rule, does not show any marked changes for some months. By the time that the above improvement has been effected the physician will be in a position to lay down the dosage of the thyroid preparation which will be required to be maintained through life, and about r fluid dr. (so to 12 grs. dry) weekly, as already mentioned, will usually he found sufficient. Some patients get satisfactorily by dividing this amount evenly over each day, whilst others manage to take the requisite quantity every second, third or fourth night, and some do well on half this amount. The excessive clothing which was formerly necessary to maintain the reduced body-heat may then be gradually diminished.