ALTERATIVE, DEOBSTRUENT, AND DIURETIC 319 



ACTIONS AND USES. Potassium iodide closely resembles 

 iodine, but is less powerful and devoid of local irritant action. 

 Medicinal doses are antiseptic, alterative, deobstruent, 

 expectorant, and diuretic. Sodium iodide has the same 

 actions. 



It is readily soluble, and is quickly absorbed ; in the tissues 

 it undergoes decomposition ; the iodine, when liberated, 

 apparently combines with albuminoids, and acts specially 

 on the thyroid gland and, in fact, on glands generally, modify- 

 ing nutrition, hastening metabolism, and promoting absorp- 

 tion. It is doubtless in this way that it also unites with lead 

 and mercury albuminoid compounds deposited in the tissues, 

 renders them soluble, carries them into the circulation, and 

 causes their elimination. It is quickly excreted by the 

 mucous and skin surfaces, in all the secretions, but chiefly 

 by the kidneys. Full doses increase both the solids and 

 fluids of the urine. 



Toxic EFFECTS. Large doses, such as three ounces in 

 horses or cattle, or a drachm in dogs, enfeeble the heart, and 

 also the spinal and cerebral functions. It causes iodism, 

 especially when it is mixed with iodates ; but this chronic 

 poisoning is much rarer in animals than in man. Dogs 

 receiving two or three drachms dissolved in water vomited, 

 showed great depression, and died in a few days from the 

 effects of the salt action and irritation ; rabbits were 

 similarly affected by one drachm ; three drachms, injected 

 beneath the skin of the back of a dog, caused extensive 

 subcutaneous inflammation, and death in three days. 

 Iodine is detected after death in the blood and urine, in the 

 brain and spinal cord, in most of the internal organs, and 

 even in the muscles and bones (Cogswell). 



MEDICINAL USES. It is given, either alone or with iodine, 

 to promote absorption of morbid products, as in lymphan- 

 gitis in horses, pleuritic and other serous effusions, enlarged 

 glands and lung consolidations in ah 1 animals. For such 

 purposes full doses are generally prescribed twice or thrice 

 daily for a fortnight, and, where the lesions are superficial, 

 iodine and soap liniments are also used externally. It is 

 useful in cases of enlarged thyroid simple goitre where the 

 secretion is scanty and the gland grows to supply the 



