This section is from the book "A Treatise On Therapeutics, And Pharmacology Or Materia Medica Vol1", by George B. Wood. Also available from Amazon: Part 1 and Part 2.
Much apprehension has been entertained of the effects of opium in acute inflammations. The medicine is a stimulant: inflammation is essentially a state of over-excitement; and the two have consequently been by some considered as almost incompatible. But the fact is otherwise Experience has shown that opium is a highly useful remedy, when properly administered, in acute inflammations. In certain cases, given in full dose, at the very first approach of the disease, it will often set it aside entirely, especially if taken with ipecacuanha at bedtime, and aided in its operation by draughts of some warm tea, as the infusion of balm. It seems to preoccupy the nervous centres so as to arrest the irritant influence of the cause, while it carries off the morbid tendencies through the skin, by its diaphoretic action. The special inflammations in which opium is most efficient in this way are those of the respiratory passages, as coryza, angina, and bronchitis, and different forms of rheumatism, particularly the subacute. There is sometimes, however, danger, if it should fail of its effects, that it may somewhat aggravate the affection; and the method is not generally advisable.
After the inflammation has become established, especially if it is severe, opium is at first, in general, contraindicated. Its stimulating properties are as yet in too strong contrast with the wants of the disease. Before commencing with it, the activity, both of the inflammatory action and of the attendant fever, should, in general, be reduced by depletory methods, as by purgatives, the lancet, the antimonials etc; but. at the end of two or three days, a sufficient reduction may ordinarily be accomplished, sometimes even sooner, and the opiate be safely administered.
It operates very usefully in various ways. In the first place, it alleviates pain, thereby preventing the injurious reaction of that morbid condition on the system, as well as diminishing the sufferings of the patient. But the practitioner must take care not to mistake the relief thus obtained for a positive amendment, or he may be led into serious practical error. He must learn to estimate the real state of the inflammation by other symptoms than the pain. In the second place, opium enables the patient to sleep, and obviates the exhausting effects of long wakefulness upon the resources of the system, and its direct injury to the brain. But. thirdly, it is still more influential for good, by reducing at once the inflammation and the febrile excitement, through its indirect sedative action. In the inflamed part, the nervous constituent suffers irritation as well as the vascular; and the former, reacting on the latter, aids in sustaining the excitement in the vessels, and the consequent inflammatory phenomena. This property of the nerves, when irritated, to propagate irritation to the blood-vessels, is obvious even in pure neuralgia. In this affection, though the seat of pain may be at first colour-it soon evinces signs of vascular congestion, by redness, heat, etc. Hence, in cases of inflammation, if we can diminish the nervous irritation in the part, we diminish also the inflammatory action. Opium produces this effect under the same circumstances as those in which it relieves pain, and through the same influence. Again, the local disease produces fever, partly at least, if not exclusively, by operating on the system at large through the nervous centres. If these are rendered obtuse or insensible, so as not to be susceptible to impression from the inflamed part, the reaction on the system must be diminished, and more or less in the same proportion. In this way opium has a tendency to lessen the fever in inflammation, and, as the fever reacts again on the local disease, to diminish that also.
But, to do good in inflammation, the medicine must be given in full doses, so as to act energetically as an indirect sedative. The plan which I generally pursue in acute inflammation is, after sufficient depletion, which may usually be effected in two or three days, to give opium at bedtime, combined with ipecacuanha and calomel, in a dose large enough to put the patient to sleep. Two grains of opium, two of ipecacuanha, and from two to four of calomel may be made into four pills, two to be given at once, a third at the end of an hour, if sleep is not produced, and the fourth at the end of another hour, in a similar contingency. This plan may be continued regularly till no longer required; the bowels being opened daily. The basis of a mercurial treatment is thus laid, which, if deemed advisable from the threatening character of the inflammation, may be carried into effect about the fifth or seventh day, by giving two of the pills every six or eight hours, or one at half the interval, till the gums are touched. The opiate should be gradually withdrawn when no longer needed; so that, when the patient has quite recovered, the want of it may not be felt. Inflammation occurring in different organs requires some modification of this treatment.
In acute gastritis, the opium and calomel should generally be given without the ipecacuanha, which is apt to occasion nausea.
In severe cases of enteritis and dysentery, the above treatment is specially useful; anodyne enemata being additionally employed in the latter affection, When found upon trial to allay the tenesmus. In dysentery, opium has by some been considered as contraindicated, in consequence of its constipating effects; but experience has not confirmed these apprehensions. It is, indeed, if properly timed and used, one of the most effectual remedies in that complaint, especially when combined as above recommended It relieves the spasmodic pains of the complaint, and does not interfere with the action of catharties, but probably rather facilitates it. But the caution must be observed of keeping the bowels duly open during the day.