CHLORAL HYDRATE 149 



Metabolism. The prolonged use of the drug leads to increased 

 proteid destruction and lessened oxidation and causes fatty degener- 

 ation of the internal organs but this in much less degree than with 

 chloroform. Hopkins ( 1 <J 1 1 ) , in studies upon metabolism, gave dogs 

 as much as 1.5 gm. per kilo as the daily dose, enough to produce 

 profound narcosis and anesthesia. He found no areas of necrosis 

 and only occasional very slight fatty changes in the liver, of the 

 type produced by chloroform, and no changes at all in the kidneys. 



Absorption and Elimination. Chloral is easily and quickly 

 absorbed from the digestive tract, and it may be given by the mouth 

 or rectum, the dose being the same in either case. It circulates in 

 the blood unchanged. It is eliminated chieily by the kidneys as the 

 non-toxic urochloralic acid. Urine containing this acid will react 

 to Fehling's test for reducing sugars. A small amount is eliminated 

 by the lungs. 



Temperature. Chloral hydrate is a decided antipyretic in 

 medicinal doses and toxic doses may be followed by a dangerous 

 reduction of temperature. The antipyretic action is probably due 

 to dilatation of the cutaneous vessels, decreased muscular movements, 

 and probably to depression of the heat producing center. 



Toxicology. Although chloral hydrate is a powerful hypnotic, 

 very large doses have failed to produce death. The fatal dose is 

 said to be from 5 to 6 ounces (150. — 180.0) for the horse, 2 — 8 

 drams (8. — 30.) for dogs. The characteristic symptoms of acute 

 poisoning are sleep, coma, rapid feeble pulse, slow respirations, fol- 

 lowed by weak rapid ones, muscular relaxation and collapse. Death 

 is due to respiratory paralysis. 



Treatment. Keep the animal warm, since those kept warm 

 artificially have been found able to withstand much larger doses 

 than those not so protected. The respiratory and vasomotor centers, 

 especially the former, are usually the seat of danger, and artificial 

 respiration should be instituted when there is any sign of approach- 

 ing paralysis. Caffeine should be administered since it stimulates 

 both of the above mentioned centers. Atropine, strychnine and 

 ammonia may be used as antidotes ; atropine and ammonia, for 

 action upon the respiratory center, and strychnine, because it stimu- 

 lates those parts depressed by chloral hydrate. Active diuresis 

 should be induced by administering hot drinks or, in emergency, warm 

 salines or warm tap water per rectum to promote diuresis and elimi- 

 nation of the drug. 



Therapeutics. 



1. Narcotic for Operations Upon the Horse or Cow. It is often 

 to be preferred to chloroform and always to morphine. It produces 

 only a medium narcosis which is usually sufficient for most cases. 

 One advantage of this drug is that it may be administered before 

 casting. It causes so much depression that the casting may be 



