324. DIAPHORETICS AND ANTIHYDROTICS 



This is shown by the dilated condition of the vessels of the skin in 

 fever with dry skin and in the cold sweat mentioned above. 

 Diaphoresis may be produced by: 



1. Application of heat. As hot air, vapor, water or sand baths. 



2. By preventing heat loss and increasing heat production j this 

 is done either by preventing the loss of heat through evaporation 

 (cover of some impervious material) or by protecting the skin from 

 the external atmosphere. Blankets act partly in both ways. 



3. Supplying heat in form of hot drinks. 



4. Dilatation of the cutaneous vessels. In this instance probably 

 alcohol in hot drink is superior in man at least. Then next probably 

 comes spirits of nitrous ether. This same dilatation may be pro- 

 duced by irritation of the cutaneous nerves either from the circula- 

 tion (aconite) or by counterirritation (sinipism). 



5. Nauseants. One of the characteristics of the nauseant stage 

 of emetics is sweating. Any emetic may be used for this purpose 

 whose action is easily controlled, or restricted to the desired action. 

 Dover's powder is probably the best example of this action as it 

 possesses the additional narcotic and diaphoretic effect of morphine. 



6. Stimulation of the sweat center. Camphor is efficient in this 

 manner although ammonia and especially liquor ammonium acetate 

 are probably more useful. In this group belong the whole pilocar- 

 pine series although pilocarpine alone is used in practice. 



The sweat glands are also stimulated by muscular exercise and 

 strong emotion but these cannot be utilized in medicine. 



GENERAL INDICATIONS FOR DIAPHORETICS 



In the early days of medicine sudorifics were used for a large 

 number of purposes and conditions. Then they were practically dis- 

 carded for a while and only comparatively recently has their use 

 been revived. Their uses may be summarized as follows : 



1. Eemove fluid from the body. 



2. Eemove injurious substances from the body. 



3. Promote a normal condition of a disturbed circulation. 



4. Relieve the kidneys. 



5. Increase the alkalinity of the tissues. 



6. Ophthalmology. 



V. Reduce temperature in fever. 



1. Remove Fluids from the Body. 



a. Promote absorption of dropsical effusions. They are of no 

 practical use in inflammatory local effusions as in the pleura and 

 pericardium. 



b. In the treatment of ohesity. Here they are occasionally used 

 according to the following plan: The carbohydrates are withheld 



