Pharmacologia / Fourth American, from the Seventh London Edition

by John Ayrton Paris

2. By increasing the tone of the Body in general, and that of the Absorbent System in particular.

That diminished absorption, and the consequent accumulation of serous fluids in the cellular texture, and different cavities, frequently depends upon general debility is very obvious, whence fevers, whether of the intermittent, or continued kind, which have been long protracted, are followed by œdematous swellings. In states of extreme debility the exhalant vessels would seem, from their laxity, to permit the thinner parts of the blood to pass too readily through them; this is proved by the circumstance that palsied limbs, in which such a laxity may be presumed to exist, are frequently affected with œdema, and the truth of this explanation is still farther corroborated by the advantages which accrue on these occasions from the mechanical support of pressure from bandages. In such cases, those remedies which are capable of renovating the vigour of the body can alone prove of any signal service. Dr. Blackall presents us with an illustrative case of this nature, on the authority of Mr. Johnson of Exeter, in which the tonic powers of well fermented bread occasioned in the space of a few hours an effect so powerfully diuretic, as to have cured sailors on board of the Asia East Indiaman, who had been attacked with Dropsy, in consequence of the use of damaged Rice.

Thus then do Diuretics, in some cases, cure by Evacuating, while in others, as in the instance above cited, they Evacuate by curing.

A case has lately occurred in my own practice, which not only affords a striking illustration of the present views, but is well calculated to convey to the inexperienced practitioner a very instructive lesson of caution. A man of the age of thirty-five, of the most dissolute habits, was attacked after a debauch of several days’ continuance, with inflammatory symptoms in the chest; a very large quantity of blood was suddenly abstracted, and the bleeding was repeated after the interval of a few hours. The respiration became laborious, and I was desired to visit the patient; I found that little or no urine had been evacuated since the attack, and that there were evident symptoms of effusion, the legs were swollen, and the difficulty of breathing was rapidly increasing. Under these circumstances I directed a large dose of Ammonia with some stimulating diuretics, which were to be repeated at short intervals. On the following day the distressing symptoms had subsided, a large quantity of urine had passed, and the patient expressed himself greatly relieved; unfortunately, however, in consequence of a slight increase of his distress in the evening, an injudicious friend in attendance, took more blood from the arm—the dropsical effusions rapidly increased, and life was extinguished in the course of three days by confirmed Hydrothorax.

3. By producing Catharsis, and thereby increasing the action of the Exhalants directly, and that of the absorbents indirectly.

It has been already stated, under the consideration of Cathartics, that certain medicines of that class excite the exhalants of the alimentary canal, and occasion a very copious discharge of serous matter: by this operation the blood is deprived of a large portion of water, and the absorbents are thus indirectly stimulated to supply the deficiency; Elaterium, and some other hydragogue cathartics, may be thus employed with extraordinary success for the cure of certain forms of Dropsy, where the vital powers of the patient can sustain the violence of the remedy;—in the whole circle of medicinal operations there is nothing more wonderful than this, that an impression made on the internal surface of the primæ viæ, by a few particles of matter, should thus convey by magic as it were, an impulse to the most remote extremities, rousing their absorbents to action; and, in case of œdema there, awakening the sleeping energies of these vessels, which like millions of pumps at work, transmit the morbid fluid to the intestines and urinary passages, effecting a detumescence of the hydropic limbs in the course of a few hours, and thus affording a striking illustration of the sympathetic action of medicines, and an instructive example of the operation of those of the sorbefacient class.[^[160]]

The observations which I have thus offered will lead the practitioner to select the particular diuretic which is best calculated to fulfil the indications of each individual case; and they will at the same time point out those which cannot be administered in combination, without a violation of the law of medicinal compatibility. With respect to the general efficacy of these medicines it may be stated, that where the disease originates from organic affections of the chylo-poietic viscera, it will not be cured by the mere evacuation of the water by diuretics; but that where it has taken place from diminished absorption, these remedies may be reasonably expected to effect a cure.

DIAPHORETICS.

The term Diaphoretic has been applied to those medicines which increase the natural exhalation of the skin, and when they act so powerfully as to occasion sweating, they have been commonly distinguished by the name of Sudorifics, but as no difference exists between these remedies, but in the degree of force with which they act, we may very properly comprehend the whole under the general title of Diaphoretics: the fluid effused is also in both cases similar, but in the one it is discharged more slowly, and is carried off by the conducting[^[161]] power of the air, in the insensible form of vapour, while in the other case it is so copiously effused from the exhalant vessels, as to appear in the liquid form.

As obstructed perspiration may depend upon very different, and even opposite states of the system, so may the most adverse medicines fall under the denomination of diaphoretic remedies.