Medicinal substances are principally applied to the skin and mucous membrane; to serous membranes, to wounds, ulcers, etc., though in some few instances they have been introduced into the circulation by injecting the medicinal substance into the veins.
Application to the Skin.—Applications are made to the skin with a view to their local effect, as well as with a view to their remote influence upon distant parts.
Liniments, lotions, embrocations, fomentations, cataplasms, blisters, setons, issues, etc., are employed to relieve local painful affections, and to establish a new action and exert a derivative influence in deep-seated disorders attended with irritation, congestion, or local inflammation.
The methods of application are four, viz., the enepidermic, iatraleptic, endermic, and hypodermic.
The enepidermic method is that by which the medicinal agent is applied to the skin unassisted by frictions, as when we apply sinapisms, blisters, poultices, fomentations, baths etc.
In many instances the medicated vapor-baths, consisting of a solution of the volatile principles of either vegetable or mineral agents, afford much relief in cutaneous diseases, as well as in the diseased states of internal organs, mucous surfaces, etc.
Sinapisms, blisters and other counter-irritants are used principally for their revulsive effect; they give rise to a new point of excitation, and detract the circulation and nervous influence from internal organs to the surface. Though we can not analyze the modus operandi of this action, yet the fact (the main thing), is very apparent.
Poultices, fomentations, etc., are used to relax the parts to which they are applied, to apply heat or cold to a part, and to shield parts from the action of the air.
The iatraleptic method consists in the application of medicated substances to the surface, aided by frictions. It is also termed the epidermic method. Many substances are employed in this way, as liniments, ointments, etc.; also particular agents, as many of the narcotics, camphor, sulphate of quinia, aconite, belladonna, morphia, etc.
The endermic application, sometimes termed the emplastro endermic method, consists in applying medicated substances to the denuded dermis; the epidermis being removed by a blister.
The hypodermic method is an injection of the medicinal substance under the skin into the cellular tissue, from whence it is rapidly absorbed by the blood vessels. By this means any soluble substance may be directly introduced into the blood, and its action will be much more rapid than when taken by the stomach. Of course the remedies used in this way must be non-irritant, or else inflammation of the cellular tissue will result, followed by suppuration. The hypodermic syringe now made is a very perfect instrument, and can be used without the least danger, always avoiding veins.
Morphia is the remedy in most common use, and the solution employed is grs. x. to water ℥j. Atropia is used in the proportion of grs. vj. to water ℥j.; strychnia, gr. j. (sulphate of strychnia should be employed, and to the ordinary commercial article a small amount of acetic acid must be added); sulphate of quinia, grs. x. (three or four grains of tartaric acid is necessary to effect the solution); pilocarpin, grs. iv. Of these solutions the quantity used will vary from gtt. x. to ℨj.
Applications to the Mucous Membranes.—Agents are often applied to the different mucous membranes, as the pituitary, trachea-bronchial, gastro-intestinal, recto-colic, urino-genital, and utero-vaginal membranes.
Medicines are applied to the nasal or pituitary mucous membrane to irritate it, and excite an increased secretion, in disease of that surface and parts adjacent, when they are called errhines. The nasal douche and the spray apparatus are means of applying remedies to the nasal mucous membrane in cases of catarrh and ozaena.
Medicinal agents, when properly applied to the trachea-bronchial mucous membranes, are capable of exerting the most salutary influences. They are mostly employed for local purposes, as in phthisis, chronic bronchitis, asthma, etc. Numerous are the substances which have been applied to this membrane—nitrate of silver, sulphate of iron, cinchona, pinus cauadensis, myrrh, etc., when reduced to an impalpable powder, have been inhaled in certain states of the pulmonary organs with advantage. The fumes of tar, resins, balsams; and various ethereal solutions, have been strongly recommended as inhalations in certain diseases.
The modern spray apparatus is the best means of applying remedies to the nasal, laryngeal, tracheal, and bronchial mucous membranes. With this the fluid is finely comminuted (pulverized), so that it is carried by the air breathed to all parts. Several patterns of steam atomizers will be found in the market, the jet of steam from a small boiler carrying the medicated fluid. The air apparatus is simpler and cheaper, and will serve most of the uses in this treatment. Any agent that can be held in solution may he used in this way, and inhalations may be stimulant, sedative, alterative, tonic, increasing secretion, diminishing secretion, etc.
Simple aqueous vapor, and other medicated vapors are often highly useful in disease of the lungs and throat. The vapor may be inhaled through a teapot, or basin covered with an inverted funnel, or by inserting a tube through th stopper of a wide-mouthed jar containing the warm medicated fluid. Narcotic and emollient agents are employed in this way; also, hot vinegar, sulphuric ether, camphor, tincture of iodine, tincture of conium, chlorine gas as it issues from moistened chloride of lime, etc.
Medicinal agents are mostly applied to the gastro-intestinal mucous membrane, which is termed the method by ingestion. From the great susceptibility of this membrane to impressions made by medicinal agents, and from the facility with which they are absorbed, and the nervous sympathy existing between this membrane and other parts of the body, it presents the most useful surface for the sanative application of medicinal agents. Their remote effects are more readily and more certainly secured than when applied to any other part of the system.
The recto-colic mucous membrane is readily affected by agents which are absorbed, as opium, tobacco, etc.; but twice or three times the ordinary dose is required to produce the desired effects.
Medicines are applied to the rectum to relieve disease in that or adjacent organs, as the bladder, uterus, or prostate gland; sometimes to secure alvine evacuations, by dissolving hardened feces, or exciting the peristaltic action of the bowels; sometimes with a view to their derivative action in diseases of the brain, and occasionally to remove the ascaris vermicularis, or small thread-worm.
If the substances applied to the rectum are solid, they are termed suppositories; if fluid, enemata, lavements, or clysters.
To the urino-genital mucous membrane, caustic or medicated bougies are applied; or anodyne, demulcent, astringent, or refrigerant injections are employed; and, in some cases, medicated fluids are injected into the bladder.
Remedies are applied to the utero-vaginal mucous membrane, to remove local disease, as in inflammation, morbid growths, etc.; they are also used to check excessive secretions, sanguineous discharges, and to promote the catamenial discharge.
The American Eclectic Materia Medica and Therapeutics, 1898, was written by John M. Scudder, M.D.