This section is from the book "Dental Medicine. A Manual Of Dental Materia Medica And Therapeutics", by Ferdinand J. S. Gorgas. Also available from Amazon: Dental Medicine.
Phenate of cocaine, as prepared by Merck, is, as its name implies, a combination of carbolic acid and cocaine containing seventy-five per cent, of the cocaine alkaloid. It is a slightly colored substance, of the consistence of thick honey, and possesses both antiseptic and anaesthetic properties. Hydro-chlorate of cocaine is open to the serious objection that when applied to cut surfaces it causes dangerous systemic effects endangering the life of the patient, and has in a limited number of cases, it is asserted, caused death. The phenate of cocaine, on the other hand, containing the alkaloid, is not so prone to cause symptoms of cocaine poisoning or any bad after-effect. It is soluble in alcohol of from thirty to fifty per cent., such a solution possessing a faint odor of carbolic acid.
Dr. D. B. Kyle regards phenate of cocaine to be as good a local anaesthetic as the muriate of cocaine, and devoid of the dangerous systemic effects of the latter. The phenate of cocaine has been employed successfully in cases of cardiac disease and albuminuria, conditions which contra-indicate the use of muriate of cocaine. It is also claimed to be equal to any carbolized solution for its antiseptic properties. It can be safely used on cut surfaces. Another advantage claimed for the phenate over the muriate of cocaine is that it coagulates the albumen in the tissue, preventing the absorption of the cocaine, thereby prolonging the anaesthetic effect, although the length of time necessary to produce anaesthesia is somewhat longer than that required for the hydrochlorate of cocaine. Phenate of cocaine is employed locally, internally, hypodermically, and in powder.
The dose of phenate of cocaine is from 1/12 to 1/6 of a grain. Hypodermically for operations involving the deeper tissue, the eight or ten per cent. solution will usually produce sufficient anaesthesia, although it may be applied locally in a fifty per cent. solution, the strength in which it is sold in alcoholic solution for convenience of dilution. In solution of the strength of 50 per cent. it will coagulate albumen, and when topically applied to a mucous surface, such a strength may cause a slight slough, which may be avoided by applying glycerine to the dried surface before applying the phenate of cocaine. The 50 per cent. solution may be diluted to any extent desired by adding to it equal parts of alcohol and water. When diluted to a 25 per cent. solution its power to coagulate albumen is overcome.
Phenate of cocaine is employed as a local anaesthetic for the extraction of teeth, and when employed in a 50 per cent. strength or diluted, it is applied to the gum, previously dried, about the tooth, on a pledget of cotton, which is allowed to remain for from three to five minutes, and repeated if the anaesthesia is not sufficient. As in the use of all other local anaesthetics applied to the mouth, the patient should be cautioned not to swallow during the operation, to avoid the benumbing effect on the throat. Phenate of cocaine is also used locally for opening alveolar abscesses, treating exposed pulps, for sensitive dentine, removing tumors, hypertrophy of tonsils (carefully applied), chronic and specific ulcers, earache, removal of polypi, hypertrophic growths, and other obstructions, etc. It is claimed for phenate of cocaine that it not only relieves pain, but checks the progress of the disease.