ALTERATIVE (Lat. alter, other, another, different). In medicine, a term applied to rem edies that have been found to act• slowly and in an unknown way, improving the nutrition of the body. It is generally applied to medicines which are irritant in full do.v.es, hut whirl, almost im perceptibly alter disordered actions or secre tions; acting specially on certain glands, or upon absorption in general, when they are given in com paratively small doses, the treatment being con tinued for a considerable length of time. For ex ample, mercury is an irritant in some of its prep arations; hut when small doses of some of its preparations are given at intervals for sonic length of time, they "produce alteration in disor dered actions. so as to cause an improvement in the nutrient and digestive functions, the disap pearance of eruptions, and the removal of thick ening of the skin or of other tissues" (Boyle) ; and they will effect these changes without other wise affecting the constitution or inducing sali vation. So iodine, also an irritant in •oncen
trated doses, and poisonous in some forms, is most useful when given in small doses in certain enlargements of glands, and need not cause iodism, if carefully given. The most marked example of the alterative action of mercury and the iodides is seen in eases of syphilis.
Some preparations of arsenic are powerful alteratives in cases of skin disease. Cod liver oil (q.v.) is an alterative is used with great benefit in tuberculous conditions, rickets, and other diseases which are associated with poor nutrition. Preparations of phosphorus have a powerful alterative action. Colchicine (q.v.) is said to act in this way in gout and subacute rheumatism. Iclithyol (q.v.) is an im portant alterative in skin affections when ap plied locally. Sarsaparilla (q.v.) was formerly believed to possess stroug• alterative qualities, but it has been shown to be practically inert.