This section is from the book "Materia Medica And Therapeutics - Vegetable Kingdom", by Charles D. F. Phillips. Also available from Amazon: Materia Medica And Therapeutics: Vegetable Kingdom.
As an Anodyne, opium is without an equal. It will, at least temporarily, relieve pain of any kind; whether it be what is called merely functional, or such as depends on inflammation, or such as is the result of wounds, or of destructive organic processes, cancer for instance. It will be best, however, to defer the discussion of the employment of opium as an anodyne under circumstances of inflammation, to a separate paragraph.
The most characteristic example of the anodyne influence of opium is seen in its effect upon simple nerve-pain, such as neuralgia; or upon the pain of a severe wound, in which of course nerves must be cut, or torn, or bruised. Here its influence is direct and speedy, but there is a point that deserves attention. "When the pain, however severe, is merely felt as a local distress, and does not throw the general nervous system into commotion, it will, I believe, be invariably found that the smaller doses of opium act fully as well as, if not better than, the large. On the other hand, where the secondary general distress is great, and especially where the emotions of the patient are excited and kept on the rack by the pain, there is no choice but to place him in a state of tolerably deep narcotic stupor, so as to get rid of the influence of the mind. The smaller doses of opium may, however, be effectively used as prophylactics, even in cases where the pain (then only just commencing) would otherwise be of the severest type; as, for example, in severe neuralgia.
As a local application for pain, opium is often exceedingly useful, though often inferior to aconite, belladonna, and some other drugs. It may be applied to the unbroken skin in the form of the pharmacopceial liniment (B. Ph.); or of laudanum applied on cotton wool, or - much better - sprinkled on the surface of a hot linseed poultice. As an application to painful ulcers it sometimes has the highest value; but there are singular anomalies in this respect, and it occasionally happens that the local use of opium severely aggravates the pain of ulcers, setting up indeed a smart inflammation, with great heat, swelling, and throbbing. The ointment usually employed is not pharmaceutical, but consists of one part of soft extract of opium to nine parts of simple ointment. A much weaker preparation than this would probably be found to act better in a considerable number of cases. More will be said as to the irritative action of opium upon raw surfaces under the head of Morphia.
As a Relaxer of Spasm, opium has enjoyed for many centuries the
1 Squire's "Companion to the British Pharmacopoeia." highest reputation. As regards the reduction of local spasms in muscles that are accessible, almost everything useful that can be said may now be included under the heading of local hypodermic injection of morphia, to be presently discussed. Where, however, we are unable to obtain a proper hypodermic syringe and morphia solution, we may effect some good by the local application of hot opium fomentations, or poultices. And when the localized spasm is in a deep-seated part, for instance, in ordinary intestinal colic, we may afford relief by the internal use of opium (two to four grains solid opium, or thirty to sixty minims of laudanum). Sometimes this is usefully combined (especially in lead colic) with a moderate dose of castor-oil; and the effect may be kept up afterwards by 1/32 grain doses of morphia, given from time to time. But there is an especially important use of opium in the more formidable varieties of acute obstruction of the bowels. Formerly these affections1 were universally treated with medicines intended to increase the peristaltic action of the intestines, and the results were most disastrous. Whether the obstruction depended upon a purely functional spasm, or on local paralysis of a portion of bowel, or on the accidental snaring of a piece of intestine by a band of lymph, the effect of heightened peristalsis was simply to drive down a portion of gut from above, and increase the obstruction, besides in all likelihood producing adhesive inflammation. To the late Dr. Brin-ton was chiefly due the method of treatment by large and repeated doses of opium, the singular results of which are well described in his little treatise on Intestinal Obstruction.2 Not merely does the steady persistence in the use of such quantities as 1/2 grain, given every four hours for two or three days or longer, arrest the most dangerous symptoms, such as stercoraceous vomiting, but it positively brings about a painless purgation, large quantities of semi-fluid and dark-colored faeces being expelled, to the immense relief of the patient. It will be remembered that belladonna may often be successfully employed in the treatment of these cases of intestinal obstruction.
The effect of opium in allaying irritation and hypersecretion of mucous membranes is often remarkable. The commonest example of this is found in the case of catarrhal irritation of the mucous membrane of the nares, the larynx, and the bronchial tubes. It ought carefully to be remembered, however, that it is to the early stages of these affections that opium is specially applicable, and that its employment at more advanced periods is often hurtful. This is particularly the case in fully developed bronchitis, more especially when the secretion is copious, and the expul-sory power is feeble. Here it is quite possible to do even fatal mischief by the use of opium. And in general it may be laid down as a maxim, that moderate doses only are useful in the irritative affections of the air-passages. True spasmodic asthma stands in a somewhat peculiar position, and full doses of opium have sometimes in this complaint produced good effects; but it is now known that other narcotics, especially belladonna and stramonium, are more efficacious and less dangerous. (Fothergill3 in reference to this use of opium and its derivatives says: "It is useful in the hacking cough of phthisis, when cough is excited by the presence of diseased masses in the hangs; and where the cough is distressing and yet useless, and incapable of getting rid of the source of irritation. Here it is necessary to stop the reflex mechanism of cough. This morphia does most effectually. It is noted, however, that morphia is not an unalloyed good in such cases. In addition to its action in destroying the appetite and locking up the bowels, it lowers the respiration while checking the cough. When under the influence of morphia, the patient sweats profusely, and to the extent of producing much exhaustion. I have combined belladonna with morphia, and found that this checks the sweats, while the morphia allays the cough: .... The effect of the belladonna is not confined to the skin, but it influences the respiration favor-ably.")