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.
The preceding description requires to be qualified, especially in cases of what is called "tolerance." If the giving of antimony be commenced in fractional doses, and continued with very gradual increase, it is possible to produce full sedative effects without gastric disturbance. Again, in certain forms of illness, with altered haematosis, such as pneumonia, or in some nerve-disorders, as chorea or delirium tremens, full doses may be given without any evidence of irritation, and then "tolerance" of the drug is said to be established. Further, in some instances, 1/2-dr. and 1-dr. doses have been taken without vomiting (Hicks: Lancet, ii., 1876, p. 38), and in other cases of poisoning from very large doses, the prominent symptoms have been those of collapse, and the patient has died without vomiting or purging, or complaint of pain. Indeed, not the least of the difficulties in studying the action of antimony, we find in the circumstance that sometimes there is no post-mortem evidence of irritation or inflammation to be found, either in stomach or intestine (Handfield Jones, Bellini, Bocker). As with other powerful drugs, there may also exist some idiosyncrasy in certain persons, leading to difference in result that we cannot otherwise explain, but the account I have given represents the effects as usually observed: as a rule, it acts with most intensity on the delicate, on women, and more especially on children, and in these subjects "tolerance" is less easily induced than in men, and lasts for a shorter time. When tolerance has once ceased, great care must be exercised in resuming the drug, for it will more readily excite gastric derangement (Trousseau).