CODEINE 273 



indigestion^ and constipation and counteracts the depression of opium 

 on the respiration. Belladonna and atropine are antagonistic to opium 

 in stimulating the brain and respiration, and increasing peristalsis. Small 

 doses of belladonna combined with opium do not interfere with the sopo- 

 rific action of the latter, notwithstanding the exciting influence of the 

 former upon the brain. The bromides also promote the sedative and 

 hypnotic action of opium, and lessen the depression and nausea follow- 

 ing its administration. Opium often acts profoundly when combined 

 with chloral, and this combination is occasionally used to induce anes- 

 thesia (p. 239). Chloroform and ether are frequently prescribed with 

 opiutn to secure an additional antispasmodic and anodyne action in colic. 

 The astringents and mineral acids enhance the effect of opium in diar- 

 rheal disorders. 



Cqdeine. — Codeine in large doses causes motor excitement and con- 

 vulsions in dogs and cats. Codeine is inferior to morphine as an ano- 

 dyne and hypnotic, but is a useful sedative in relieving bronchial irrita- 

 tion and cough, and in the doses commonly employed does not induce 

 constipation. Codeine differs from morphine in not being nearly so de- 

 pressant to the respiration, and in not lessening secretion in the intes- 

 tines (absence of constipation) and bronchioles. The writer would par- 

 ticularly recommend it for dogs suffering with bronchitis, combined with 

 phenacetin in powder or tablet. The other alkaloids of opium are not 

 of sufficient therapeutic value to warrant their consideration in this work. 



Administration. — Morphine sulphate is employed hypodermically 

 where an immediate effect is required. The preparations more frequently 

 used in veterinary practice include laudanum and the deodorized tincture, 

 powdered opium, and the salts of morphine. One-quarter grain of the 

 latter is equivalent to one grain of opium. Paregoric is useful in canine 

 practice for cough mixtures. Dover's powder combines the expectorant 

 and diaphoretic action of ipecac with the sedative, antiphlogistic and 

 sudorific influence of opium, but the former drug has little effect upon 

 the horse. The preparation may be serviceable, however, in the first 

 stage of catarrhal affections of the respiratory tract in dogs. 



Fluid preparations are generally desirable in securing more rapid 

 absorption, but opium produces the best results in diarrhea, when given 

 in pill or ball. Enemata composed of thin, boiled starch solution and 

 laudanum at the body temperature are to be recommended in diarrhea 

 of the young, dysentery and pain arising from strangury or disease of 

 the genito-urinary organs. Opium suppositories are of value in canine 

 practice for the same purposes, and will relieve irritation and pain 

 caused by piles. 



Uses External. — Opium is applied extprnally in various ways. In 

 the form of laudanum it is sprinkled on poultices and prescribed in lini- 

 ment (laudanum and soap liniment, equal parts) for its anodyne action. 

 On raw surfaces, sores and ulcers, laudanum is often combined with lead 

 water (1-25)., Opium relieves pain by depressing nerve centres. It 

 doe? not appear to have any action upon peripheral nerves (Cushny, 

 Bastedo). 



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