326 DIAPHORETICS AND ANTIHYDROTICS 



It is frequently used as a vehicle for spirits of nitrous ether or aco- 

 nite. 



ANTIHYDROTICS 



These are agents which act exactly opposite to those just dis- 

 cussed. That is, they decrease the secretion of sweat. Theoretically 

 they may act by: 



1. Lessening the irritability of the sweat centers. 



2. By depressing the peripheral fibers of secretory nerves or the 



the gland cells themselves. 



3. By depressing the respiratory center. 



In regard to the last method Brunton has called attention to the 

 close relation between respiratory depression and the occurrence of 

 profuse sweating. He states that when the respiratory center is 

 exhausted from any cause it responds less readily than the sweat cen- 

 ters to the stimulating influence of venous blood in consequence of 

 which profuse sweating occurs. This accounts for the fact that res- 

 piratory stimulants are frequently efficacious in controlling the night 

 sweats of tuberculosis. The most important antihydrotics are: 



Atropine Agaricin 



Sulphuric acid Picrotoxin 



Camphoric acid Tellerium compounds 



Thallium acetate 



Gallic acid, ergot and zinc oxide have also been employed but 

 are of very doubtful value. Certain external remedies are also use- 

 ful in excessive sweating, such as sponging with a solution of vinegar 

 and water, or a hydroalcoholic solution of tannin or alum. A weak 

 solution of formalin answers well but is irritant to the eyes and 

 respiratory tract. There are no specific indications for the use of 

 antihydrotics in veterinary medicine, and they are used in human 

 practice principally in night sweats of tuberculosis. 



