ACTION OF ACETANILID, ANTIPYRIN AND PHENACETIN 303 



Properties. — Colorless, odorless, scaly crystals, of a bit- 

 terish taste and alkaline reaction. Soluble in about its own 

 weight of water, alcohol and chloroform. 



Incompatihles. — Spirit of nitrous ether, iron sulphate, 

 chloride and iodide ; salicylates, tannin, chloral, calomel, 

 and a large number of drugs. 



Dose.—K. & C, 3 iii.-iv. (12.-15.) ; Sh. & Sw., 3i. (4); 

 D., gr.v.-xx. (.3-1.3). 



ACTION OF ACETANILID, ANTIPYRIN AND PHENACETIN. 



External. — Acetanilid and antipyrin are antiseptics. 

 Solutions of the latter contract vessels and exert a haemo- 

 static action. 



Internal. — These substances exert no action upon the 

 digestive tract, but acetanilid possesses a decided antiseptic 

 influence upon bacteria within the alimentary canal. 



Blood. — ^These agents have no influence upon the blood, 

 in moderate medicinal doses, but in large doses they dimin- 

 ish the ozonizing power of the blood, reduce the haemoglobin 

 of the red corpuscles, change it to methsemoglobin, and 

 alter the color of the blood to a brownish-red hue. In 

 large toxic quantities, administered continuously, they cause 

 disintegration of the red corpuscles and elimination of the 

 blood coloring matter in the urine. 



Heart and Blood Vessels. — In ordinary therapeutic doses 

 these drugs do not alter the normal condition of the heart 

 or blood vessels, but in large medicinal doses they depress 

 the force of the heart by action (probably) upon the heart 

 muscle. Phenacetin is the least, and acetanilid the most 

 depressant. Antipyrin is said to stimulate the heart and 

 increase blood pressure in minute quantities. These three 

 antipyretics decidedly diminish blood tension in large medi- 

 cinal doses, owing to depression of the vasomotor apparatus. 



Nervous System. — Usual therapeutic doses of these sub- 

 stances exert a sedative action upon the sensory nerves and 

 sensory tract of the spinal cord. They are therefore anal- 

 gesics, although not comparable in this respect to opium. 



