46 GENERAL ACTIONS OF DRUGS 



v.— Drugs Acting on the Ear. 



Strychnine makes the hearing (and sight) more acute ; 

 while salicylic acid, salicylates and quinine cause, in man, 

 subjective symptoms, including fulness, roaring and buzzing 

 noises in the ears. 



Drugs Acting on the Respiratory Organs. 



It is impossible to describe under this head all the 

 drugs influencing the respiratory tract. Thus, agents affect- 

 ing the circulation exert a powerful action on the blood 

 supply and functions of the respiratory organs. The appli- 

 cation of counter-irritants and heat and cold externally, 

 reflexly produce notable alterations in pulmonary conditions. 

 Emetics are indirectly serviceable in assisting the expulsion 

 of exudations from the upper air passages in dogs. Further- 

 more, medicines having a depressing action on the nervous 

 system are of importance in respiratory disorders in reliev- 

 ing cough and spasm. We shall consider here those agents 

 acting on the respiratory apparatus itself. 



Drugs Acting on the Eespiratory Mucous Membrane. 

 (A) Drugs Acting Locally. 



1. Stimulating the mucous membranes and causing 

 vascular dilatation, increased secretion and muscular con- 

 traction of the walls. 



2. Producing a sedative action. 



3. Exerting an antiseptic influence. 

 4.' Relaxing spasm. 



5. Causing a local astringent action. 



6. Thinning exudations. 



Errhines, or sternuatories, are drugs which are intro- 

 duced into the nostrils to cause irritation, coughing and 

 sneezing and expulsion of secretions, parasites and foreign 

 bodies from the nasal chambers and upper air passages. 

 They are rarely of any value, and include tobacco, ipecac, 

 euphorbium, ammonia, chlorine and sulphurous anhydride. 



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