This section is from the book "Botanic Drugs Their Materia Medica, Pharmacology and Therapeutics", by Thomas S. Blair. Also available from Amazon: Botanic Drugs, Their Materia Medica, Pharmacology and Therapeutics.
Coca Leaves, Erythroxylon Coca. Official in only seven foreign standards and in the eighth U. S. P. Little used except as a source of cocaine.
Small doses of cocaine cause nervous excitement, varying in manifestation in different individuals. Larger doses increase the frequency of the pulse, cause muscular tremor and finally spasm, with rapid breathing and convulsions in fatal cases of poisoning. These phenomena are due to stimulation followed by depression of the central nervous system. In some individuals the initial stimulation is transitory. Cocaine causes vaso-constriction. Injected locally it paralyzes temporarily the sensory nerve-ends, the action being direct. Little effect is noted upon the unbroken skin except when the drug is incorporated with a fatty base. The senses of taste and smell are blunted when the drug is applied in the mouth and nose. In the eye cocaine produces local anesthesia, constriction of the vessels, and, finally, dilatation of the pupil, but to a less degree than does atropine. Injected into the spinal theca, cocaine causes nerve-blocking and widespread anesthesia.
Coca, by stimulating the motor cortex and diminishing certain sensations, as of fatigue and hunger, seems to act as a tonic; but there is practically no justification for its use in this direction. The so-called "tonic wines" containing it should be banished from therapeutics. The "average dose" of the fl. is 30 minims, and there are a few cases of reflex vomiting, as aggravated vomiting in pregnancy, in which it may be used, though Cycloform is safer. Don't forget that coca and cocaine are habit-inducing drugs.
The use as a local anesthetic has been extended so that now elaborated technic has developed, taking extended chapters in surgical and special works to outline them. It would be unwise to attempt to cover that surgical subject in brief compass here; so the reader is referred to special works. An admirable book upon the subject is that of Hertzler, entitled "Surgical Operations with Local Anesthesia." (Surgery Pub. Co., New York.)
Indeed, while we can say here that cocaine hydrochloride may be used in 1 to 4 per cent. strength in the urethra, 2 to 4 per cent. in the eye, 5 to 10 per cent. in the nose and larynx, 10 per cent, in the vagina and rectum, 0.01 to 0.05 per cent. in 0.8 per cent. saline solution in infiltration anesthesia, and that tablets of 1-6 grain cocaine hydrochloride with 1-300 grain adrenalin, as borate, are used when the joint action of the two agents are desired, little useful information is conveyed. Physicians will avoid a world of trouble if, before they undertake local anesthesia, except in its simpler forms, they inform themselves most fully in the technic of the subject. The matter is very far indeed from being a simple one; and both physicians and dentists are commonly encountering difficulty, sometimes serious, from ignorance of a host of little details absolutely necessary to be observed in the practice of local anesthesia. Know exactly what you are doing; then go ahead. Never trifle with cocaine.
Cocaine Substitutes are based on the fact that the local anesthetic action of cocaine is due to the radical of benzoic acid therein being in combination with a nitrogen-containing base. Cocaine is methyl-benzoyl-ecgonin; and the substitutes are synthetic compounds, such as the ethyl, propyl, and isobutyl esters of para-amino-benzoic acid and combinations of benzoic acid with derivatives of an amino-amyl alcohol. Most of them are less toxic than cocaine, and some of them dilate the blood vessels, which may be an undesirable property.
Alypin is one-half as toxic as cocaine, is not mydriatic, and is used externally in 10% solution; in the eye, 1 to 2%; and injected in 1 to 4%. May be boiled not to exceed 5 minutes without being decomposed.
Anesthesin is non-toxic, does not penetrate mucous membranes, and is too insoluble for hypodermic injection. Its action is prolonged, and it may be used internally in gastralgia, ulcer, and cancer of the stomach for the relief of pain. Used in rhinology and laryngology largely. Dose: 5 to 8 grains. Externally is applied pure or diluted in ointment. Is available for incorporation in suppositories.
Beta-Eucaine Hydrochloride is much less toxic than cocaine, does not dilate the pupil, does not contract the blood-vessels, and may be freely boiled in solution. Used as is cocaine, 2 or 3% in the eye; 5 to 10% for nose and throat; and 5 to 10% in ointments.
Beta-Eucaine Lactate is more soluble than the preceding and is used in 2 to 4% in injecting; 1 to 2% in the eye; from 10 to 15% on mucous surfaces; and 1:500 solution with sodium chloride 0.6 to 1% in infiltration, with or without epinephrine.
Cycloform is soluble with difficulty; practically non-toxic; prolonged anesthetic and mild antiseptic; used as a dressing, in ointments 5 to 20%, and in suppositories. Internally, in cardialgia and obstinate vomiting, in doses of 1 to 3 grains.
Novocaine is very soluble, is very slightly irritating, and is not markedly toxic. Solutions withstand boiling. The anesthesia is brief, owing to vaso-dilation; but adrenalin or epinephrine may be added, which prolongs the anesthesia. For infiltration, 4 grains in 1.6 to 3.2 ounces physiologic salt solution, with 5 or 10 drops epinephrine solution (1:1,000). For instillations and injections, solutions of 1 1/2 grains in 150 or 75 grains salt solution (by weight), with or without 10 drops epinephrine solution (1:1,000). In ophthalmology, 1 to 10%; rhinolaryngology, 5 to 20%. Internal dose for adults, 3 to 7 1/2 grains.
Orthoform - New is practically non-toxic and but slightly soluble, not penetrating the tissues. Used internally to relieve the pain of gastric ulcer (8 to 15 grains) and as an analgesic to wounds, in dentistry, hay fever, etc.
Propaesin is practically non-toxic, said to be stronger than anesthesin. It is slightly astringent and is used similarly to other agents of its class. Dose: 4 to 8 grains.
Stovaine is one-half as toxic as cocaine and is similar to alypin. The internal dose is 1-30 grain in pill form. In the eye, up to 4%; and in laryngology, up to 10%. May be sterilized at 115° C.
Tropacocaine Hydrochloride is one-half as toxic as cocaine; it produces little dilatation of the pupil. Used in 3 to 10% aqueous solutions containing 0.6% sodium chloride. Put up in 1-grain sterilized tubes.
The cocaine substitutes are displacing cocaine in several lines of usage. The fact that some of them may be sterilized by boiling and without losing activity makes them of great importance to the surgeon.
Also see quinine and urea hydrochloride under "Quinine."