44.8 GERMICIDES — DISINFECTANTS 



hoi have little antiseptic action because phenol has a greater affinity 

 for them than for the water or proteids of the tissues. 



External and Local Action. When applied to the skin in 

 concentration, phenol whitens the skin, causing a burning sensation, 

 followed by a slight anesthesia. The blanched skin later assumes 

 a brownish tint and the epidermis is desquamated. This action is 

 due to precipitation of the proteids with which it comes in contact 

 and may be prevented by washing with alcohol or glycerin in which 

 it is very soluble. In weaker solutions phenol is anesthetic and 

 antipruritic. It is absorbed from the intact skin, but more readily 

 from mucous membranes, and paralyzes or depresses the sensory 

 nerve endings. Since phenol coagulates the proteids of the tissues, 

 its action is not deep after single applications, but if kept in con- 

 tact with the skin for a considerable time local gangrene may result 

 even when dilute solutions (5 per cent.) have been used. 



Digestive System. In small doses it is anesthetic and seda- 

 tive to the stomach, in large doses, a gastrointestinal irritant. 

 Therapeutic doses are converted into phenolsulphonates. 



Circulatory System. Medicinal doses have little if any effect. 

 Larger doses first accelerate and then slow the heart. Toxic doses 

 are followed by a marked fall in blood pressure due to cardiac and 

 vaso-motor depression or paralysis. 



Nervous System. Therapeutic doses exert no action. Large 

 or toxic doses depress the cerebrum, causing stupor and coma. In 

 animals tetanic convulsions are often seen and are foUoM'ed by de- 

 pression, suggesting that the spinal centers are first stimulated and 

 then depressed. Applied locally it is an anesthetic and produces 

 this action by depressing the peripheral sensory nerves. 



Respiratory System. The respirations are first stimulated 

 and then depressed by toxic doses. Death is usually due to 

 asphyxia. 



Temperature. Temperature is reduced in fevers. Large or 

 toxic doses dangerously lower temperature. Phenol acts on the 

 temperature similarly to the coal tar antipyretics. 



Absorption and Elimination. Phenol is absorbed very easily 

 and rapidly from the skin, wounds and mucous membranes. It is 

 eliminated by all channels, but most of it escapes with the urine. A 

 portion is combined with sulphuric and glycuronic acids in the tis- 

 sues and is eliminated as the double sulphate and glycuronate of 

 phenol ; a portion is oxidized into hydroquinone and pyrocatechin. 

 Large doses are followed by smoky urine. Ischuria and albumin- 

 uria are common in poisoning. 



Toxicology. Acute or corrosive poisoning is rarely seen in 

 animals. Cats are most susceptible to this drug and may be killed 

 from too free use of it as a disinfectant for their quarters. Ac- 

 cording to Law, from. 3 to 4 drops per pound is the minimimi fatal 



