RESPIRATORY, CARDIAC, AND DROP SICAL MALADIES.—CaRtharides is occa sionally administered internally with benefit in passive dropsies with a view of stimulating the action of the kidneys, but it is inadmissible in sthenie or acute cases; it should be administered in con junction with some other diuretic, how ever, such as a decoction of broom, fusion of digitalis, or sweet spirit of nitre. In the form of blister the cerate is also useful in these maladies, as well as in pericarditis, pleuritic, pneumonia, and more rarely phthisis.
Within a few years the cantharidate of potassium has been employed as a remedy for puhnonary and laryngeal tuberculosis, on the strength of some experiments undertaken by Liebreich: also the eantharidate of cocaine. breich's theory is that the inflammatory processes set up by the eantharidin pro duce a transudation of sanguineons mi crobicidal serum.
The chief points to be decided are whether eantharidinates have any ac tion on diseased. particularly tubercu lous, tissues. and. if so, whether this effect is obtained before any disturbance is produced in other organs. such as the kidneys. The cantharidinate gives rise to an increased exudation from the capillaries: hence its beneficial action: hut there is no hyperemia. Advanced tuberculosis. however, should be treated with extreme caution, for the kidneys are often fattily degenerated. Improve ment has been recorded in other than tubercular processes.--e.g.. in chronic laryngitis. Any local application of a cantharidinate is not rational. as it only produces irritation. In hundreds of in jections made, there has been no more danger to the patient than from the use of mercury or arsenic. Liebreich (Therap. Monat., June, '92).
Recently, Liebreich and others have recommended the subcutaneous use of cantharidin in combination with alka lies in the treatment of tuberculosis. While the value of this method is still undetermined, the accumulated testi mony gives little encouragement for its employment in this affection. In pneu monia, pericarditis, etc., cantharides is
a most useful vesicant.
BLISTERS.—These are applied to es tablish a degree of inflammation or irri tation on the surface of the body, and thus to substitute a mild and easily man aged disease for an internal and intract able one, on the principle that two sets of inflammation cannot be carried on at the same time: a theory that admits of some question; to stimulate the absorb ents and thus cause the removal of effused fluids; to act as derivatives; to stimulate the whole system, and raise the vigor of the circulation. A few rules find universal application as re gards the use of these agents, viz.: Never apply a blister at the beginning of in flammation,—never until the acute stage has been subdued by other means. Never apply where the skin is thin or tender nor over a bony prominence, as great irritation will result, and the heal ing will be slow and difficult. In many instances, as in acute laryngitis, it is not advisable to apply a blister directly over the seat of the disease, as it sometimes aggravates the symptoms; indeed, a blister is often more efficacious if applied at a remote point, as to the heel in sci atica or lumbago. As a. rule, it is not advisable to allow a. blister to remain on the part to which it is applied more than two or three hours,—only until it has produced considerable redness, when the process may be completed by soft, warm poultices. A blister has been known to produce abortion when applied to the neck or chest of a pregnant woman. Blisters applied to a scorbutic person are apt to induce ulceration and gangrene; and the same is, in a measure, true as regards this application to children, who, as a rule, bear vesicants badly. Finally, the danger of absorption of cantharides from cantharidal vesicants, sufficient to induce untoward phenomena, and even toxicity, should always be considered. Violent strangury has resulted in some instances from the application of a blis ter to the penis with a view of prevent ing masturbation.