This section is from the book "Materia Medica And Therapeutics Inorganic Substances", by Charles D. F. Phillips. Also available from Amazon: Materia medica and therapeutics.
In this malady the sulphate of copper has been highly esteemed, especially by German and French physicians, since its first introduction by Hoffmann; he used it mainly as an emetic, but the question has arisen whether it does not exert a specific action upon the false membrane. Kissel, who reports successful cases from the use of non-emetic doses of the acetate, supports this view (Journal fur Pharmaco-dynamik.), and Missoux, who also speaks highly of the remedy, but who gave 5-gr. doses, argues in favor of specific action, because the false membrane, after becoming detached, either does not form again, or if it does so is no longer so plastic, tough, and adherent (Bulletin de Therapeutique, December, 1858, abstract in Medico- Chirur-gical Review, ii., 1859). In judging of the curative results, we must bear in mind the distinction between simple catarrhal laryngitis and the membranous form (true croup), since the former is more likely than the latter to have a favorable issue independently of treatment, but allowing for this, there can be no doubt that most of the cases of Godfrey and of Beringuier were of the more serious malady; these observers used emetic doses (2 to 4 gr.) and also depletion. Trousseau used it mainly as an emetic, in doses of 5 gr., twice repeated (Gazette des Hopitaux, No. 39). I do not ignore the six fatal cases recorded by Dr. Hannay (London Medical Gazette, July, 1840), nor the adverse opinion of Nothnagel, who fears its injurious effects on the intestinal tract, but still I consider the remedy of value. Dr. Crighton states (Edinburgh Medical Journal, May, 1868) that out of fifty cases of croup treated by him with the sulphate, only six died; he gave 1/2 gr. every ten to fifteen minutes till vomiting or marked relief occurred; but even these doses are rather large for children, and, in fact, he records that two of them had violent diarrhoea. I recommend doses of 1/8 to 1/4 gr. for children, to be given every quarter to half hour until vomiting is induced; then the dose should be diminished and given at longer intervals so as to avoid too severe effects, and later it may be increased again should it become necessary to produce emesis. This plan may be adopted in true croup during the stage of development of the membrane when there is a dry barking cough, and sense of constriction across the chest, with much difficulty of respiration: and it is also serviceable in cases where a loose catarrhal cough assumes a dry croupy character, when there is partial aphonia, and often some sanguineous discharge from the throat and nostril.
The following notes of an illustrative case have been furnished to me by Dr. Mackey: - E. S., a girl, aged three, was hoarse on April 7th; on the 9th became feverish and restless, with hurried, loud, and stridulous respiration, and clutching at the throat; there was no exudation on tonsils: has had castor-oil, poultices, and steaming, now ordered 6 min. of ipecacuanha and 6 of antimonial wine every hour: vomited after the third dose, but the oppression continuing, a teaspoonful of the ipecacuanha wine was given and caused freer vomiting.
On the 10th there was, however, no relief, the stridulous croupy breathing being more marked, the face flushed, not very dusky; pulse 120, respiration 36; drowsy, yet restless. (10 a.m.): to omit other treatment and take 1/2 gr. of copper sulphate every half-hour in water. (1.30 p.m.): has had four doses; vomited freely after the first two, and slept comfortably; is better, pulse 110, respiration 32. (6 p.m.): one dose since; vomited and moderately purged; pulse 110, respiration 28, temperature 100°; speaks better, and smiles. (11th, 9 a.m.): has slept fairly well, lying down; had two doses, and vomited after each; looks much better; respiration 32, temperature 98°; bowels moved once. 12th: Convalescent, though still some stridor when asleep; an occasional dose of the copper relieves sensibly. The child got quite well.