GLYCERIN. — Glycerin (Glycerinum, U. S. P.) is a colorless, syrupy liquid, of a sweet, warm taste. It is obtained by the saponification of fats. It is soluble in water and alcohol. Exposed to the air it does not become rancid or undergo fermentation, and it increases in weight on account of its great hygroscopic pow ers. Glycerin possesses decided antisep tic and solvent powers.
Preparations and Doses.—Glycerin, 5 to 120 minims.
Glycerite of carbolic acid, 2 to 5 min ims.
Glycerite of tannic acid (tannic acid, 20 per cent.), used locally.
Glycerite of starch, used locally. Boroglyceride.
Glycerite of hydrastis, used exter nally.
Glycerite of vitellis (glyconin), used for emulsifying.
Glycerin suppositories.
Physiological Action. — Glycerin in the pure state is slightly irritating when applied locally to the skin or to the mu cous membranes; it excites the secre tions and causes an increased flow of blood to the parts; in some subjects it produces pain and decided irritation. The ingestion of glycerin causes no ap preciable systemic effects. It sometimes acts as a laxative, but does not seem to affect digestion. Injected into the cir culation in large amounts, glycerin causes convulsions, due to its hydro scopic powers (Hare). Although Pavv asserts that the ingestion of glycerin by diabetic patients increases the polyuria, others believe the contrary to be true, and find advantage in its use. The glyc erin in stores other than responsible pharmacies is apt to contain arsenic. Vegetable glycerin should be preferred.
Therapeutics. — Good results have been obtained in the use of glycerin as a substitute for sugar in the alimentation of diabetic patients, but care must be taken that pure glycerin be adminis tered.
Certain forms of glycosuria may be checked by glycerin. It acts more effi ciently when introduced into the ali mentary canal than when injected sub cutaneously. It checks glycosuria by inhibiting the formation of sugar in the liver. By this means glycerin increases the quantity of glycogen found in the liver. Ranson (Jour. of Physiology, vol.
vii, p. 202, '89).
[According to the clinical researches of Pavy, glycerin increases the polyuria of diabetes almost one-half, and for this reason he thinks it is not to be em ployed in this class of cases as a substi tute for sugar. The quantity of glycerin recommended to be given, clinically, is 1 drachm, diluted with water at least one-half. II. A. HARE, Assoc. Ed., An nual, '90.] constipation the use of glycerin suppositories is followed by excellent results, but a too long-con tinued use may produce rectal irritation. When suppositories are not available, or for any other reason, glycerin may be given by rectal injection, 1 to 4 drachms being used.
Glycerin enemata tried in 26 cases, be sides children, and it was found that 50 minims at once produced a copious evacuation, without leaving any dis agreeable sensation. In no case did the drug lose its effect, though sometimes given regularly for many months. Sei fert (Minch. med. Woch., No. 9, 'SS).
Toxaemic symptoms may be suddenly produced by the use of ordinary ene mata. A solution of some of the prod ucts of decomposition may take place, and a diffusible septic poison thus be introduced into the system by means of the lymph- and blood- vessels in that neighborhood. A rash may appear in these post-enemal eases, and, from ap pearances, cases have been pronounced scarlatina or r6theln. No such symptoms or rash, however, have been observed in glycerin enemata, the amount injected being too small. G. H. Burford (Lancet, Dec. 15, 'SS).
Glycerin enemata tried in a long series of cases with good results. In patients with hmmorrhoids, however, the insertion of any syringe may be productive of pain. In 20 eases hollow suppositories of cacao-butter employed, each containing 15 minims of pure glyc erin. This dose was found sufficiently large, and acting in fifteen to twenty minutes. It was never necessary to use more than one suppository, though there would be no objection to giving two. Boas (Deutsche med. Woch., No. 23, '88).