180 CHLORAL HYDRATE. 



CHLORAL HYDRATE. 



Chloral, or trichloraldehyde (C 2 HCl3O + H 2 O == 164.12), is obtained by treat- 

 ing absolute alcohol with chlorine. 



Pharmacodynamics. 



Central Nervous System. Chloral depresses the receptive functions of the brain, 

 renders less responsive the motor areas of the cortex, lowers reflex activity in the 

 cord, and finally depresses the medulla. 



Muscular System. No direct action. 



Respiration is rendered slightly slower and shallower. Ultimately it is paralyzed 

 by centric action. 



Heart is not affected by therapeutic doses. Toxic doses, by direct action on the 

 heart muscle, cause a marked slowing, with auricular weakness and ventricular 

 dilatation. 



Blood-pressure affected by toxic doses only, when it is lowered by weak heart 

 action and by paresis of the vasomotor center. 



Alimentary Tract. Irritation varies with concentration. 



Metabolism. Proteolysis augmented; fatty degeneration induced. 



Temperature is reduced from lessened muscle activity, and from increased peri- 

 pheral dissipation of heat. 



Absorption. Chloral is rapidly absorbed from the alimentary tract, and from 

 the blood by the nerve cells. 



Excretion takes place in the urine as urochloralic acid. 



Local Action. Irritant, becoming vesicant if concentrated. 



Tolerance is soon acquired. Prolonged abuse of chloral leads to digestive dis- 

 turbances, exanthemata, general depression, and cachexia, mental impairment, and 

 fatty degenerations. 



Symptoms. 



Therapeutic Doses. Toxic Doses. 



Drowsiness and weariness. Total unconsciousness. 



Light somnolence. Muscle relaxation complete. 



Quiet respiration and pulse. Respiration slow and weak. 



Effect lasts from 6 to 8 hours. Pulse slow and weak. 



Slight giddiness a sequence. Reflexes abolished. 



Contracted pupil. 



Cold, clammy skin. 



Paralysis of respiration. 



Therapeutics. 



Chloral is used to quiet nervous excitement, to induce sleep, and to relieve convul- 

 sions. Not an analgesic. 



Dosage. 



0.3 to 2 Gm., freely diluted. 



Sulphonethylmethane and Sulphonmethane may be used in place of Chloral. They 

 are attended with some danger, but show less after-depression, and usually produce as 

 refreshing a sleep. Dose of either, 0.6 to 2 Gm. 



