90 JOHN T. HALSEY 



in the fact that almost universally after thyroid has been taken for a time, 

 the dose mapy be decreased to one-fifth or one-tenth (or an even smaller 

 fraction) of the dose required at the commencement of the treatment. It 

 is entirely possible, although not definitely proven, that the thyroid, 

 which is administered, acts not only substitutionally (i. e., by supplying 

 the deficiency of thyroid secretion), but that just as it acts beneficially on 

 the function of various organs, it may also improve the function and 

 perhaps, too, restore to a healthy state such thyroid tissue as may still be 

 present and able to function. 3 It is also not impossible that the improve- 

 ment in function of other endocrin glands, resulting from the thyroid 

 administration, may in turn exert a favorable influence on the diseased 

 thyroid. 



Dosage. In all these conditions, whether classed as myxedema, 

 cachexia strumipriva, or cretinism, the indications for and details of the 

 administration of thyroid are essentially the same. With the varying 

 degree of deficiency of function, however, there are marked differences in 

 the doses necessary and in the results obtained. The correct dosage can be 

 determined only by trial and varies within wide limits. 4 It is well to 

 start with relatively small doses which will be increased or diminished 

 according to the effects obtained. While in many cases doses ranging 

 from 1 to 5 grains of the dried gland per diem will be found sufficient, 

 occasionally, at the commencement of the treatment, much larger doses, 

 up to 15 or 20 grains (or very rarely even more) may be necessary, but 

 such doses are dangerous. Once the desired effect has been obtained, it 

 is the almost universal experience that it can be maintained by much 

 smaller doses. In an adult case of ordinary severity, a daily dose of 3 to 6 

 grains of the dried thyroid will usually suffice in the early stages of treat- 

 ment, and 1 to 2 grains daily will usually be sufficient as a maintaining 

 dose/' 



In cretins the dosage is (in proportion to the weight) the same as in 

 myxedema but occasionally much larger amounts are required. Sajous 

 ( 1 !>!!>) gives the following as average dosage: For an infant, % grain 

 daily; at two years, I/, grain twice daily; older children, l 1 /^ to 2 grains 

 daily. Von Jaurogg believes that the failures of treatment reported by 

 certain authors were due to too large doses. He has found it best to 

 start with 0.1 gram (li/, grains) per diem and to increase this only 

 gradually. An initial dosage of 5 grains daily will, he states, at least 



3 That thyroid administration can exert an influence on the thyroid gland tissues 

 shown by tin- results of thyroid therapy in goiter. That it can strikingly stimulate 

 thyroid function seems proven l.y the disastrous results which have followed thyroid 

 feeding in some cases of exophthalmic goiter. 



1 Hummer has shown, however, that the determination of the basal metabolic rate 

 will enable , m ,, lo calculate U, r necessary dose of thyroxin very closely. 



ascs have been reported in which very much smaller doses sufficed to maintain 



ictory condition, Murray having reported one case in which a small dose every 



s was sufficient, while Zum P.usch reported two cases in which 5 grains every 



< patients in a satisfactory condition. (Quoted from von Jauregg.) 



