Perspiration is diminished under bromide of potassium. Various kinds of eruption, erythematous or acneiform in character, are commonly traced to this drug, and although several observers maintain that they are wholly due to some contained iodide, they seem in greater or less degree inseparable from bromide medication, and occur with almost equal frequency after the ammonium, sodium, or other compounds.

They affect mostly the face, the arms, the back, and the buttocks, but may be general. They present papules, vesicles containing sebaceous matter (seborrhoea - Fox), or pustules, and even crusted tubercles of car-buncular character, and have been termed "confluent acne" (Cholmeley) and "molluscoid acne" (Neumann). Voisin distinguishes five different kinds of "bromide rash" (Archives Generales, 186G-67). Usually there is a hard, red swelling, with a small point of suppuration in the centre; this may be quite small - a mere papule - or of large size. An eruption of this kind has occurred in a child at the breast, whose mother was taking the medicine and who was not herself affected (Lancet, ii., 1874, p. 657). A more rare, but still recognized form, is that of erythematous patches, which may be local or general (Veiel: Medical Times, ii., 1874, p. 152; i., 1878, p. 151).

Therapeutical Action (Internal)

In 1826, Barthez, Andral, and some few other (French) observers, ascertained that the bromide of potassium could relieve arthritic pain, and Pourche found it useful in bronchocele. Dr. Robert Williams (of St. Thomas' Hospital) reported such success with it in the treatment of enlarged spleen, as to contribute to its introduction into the London Pharmacopoeia of 1835, and yet it is instructive to remark, that so little clinical evidence of its value was obtained by others, that the medicine was omitted in that of 1851. Puche, however, found it to cause partial anaesthesia; and Thielman, a Russian physician, noted its sedative influence on the generative system; and from these suggestions Sir Charles Locock was led to use it in epileptic or epileptiform attacks, connected especially with ovarian or uterine excitement, and the mention of his successful results at the Medico-Chi-rurgical Society in 1857 was practically the commencement of general knowledge upon the subject.

Synergists

The sedative action of the alkaline bromides on the nervous system is assisted or modified favorably under certain conditions by chloral, cannabis, and opium; their regulating effect upon vaso-motor nerves, especially by quinine; their depressant effect upon the circulation is aided by aconite, gelseminum, veratrum viride, and digitalis, also by nitrate of potash and allied salts; their alterative power is increased by cod-liver oil, iodides, and alkalies, though iodides would interfere with sedative action.

Antagonists

True stimulants, such as alcohol, ether, and coffee, which tend to induce arterial congestions, oppose the action of bromides; thebaine and narcotine, strychnia, and nicotine, are also antidotal. Strychnia especially has an opposite effect on the cord and medulla oblongata, though without a direct action on the brain or the muscles. The difference in the capillaries of the spinal centres post-mortem, after using the two drugs, was especially noted by Saison; under bromide the vessels were scarcely visible, under strychnia intensely congested.

Atropia antagonizes in some degree bromal hydrate (Hughes Bennett: British Medical Journal, i., 1875), and ergot is opposed, in its full action, to bromides - although any of the above-named drugs may at times be usefully combined with them, and made to modify their ordinary action for certain therapeutical results. This is evidenced by clinical experience.

Dr. Bill argues that chloride of sodium is antagonistic to bromide of potassium, and that the latter remains longer in the system if the former salt be avoided (American Journal, 1868).

The value of arsenic in curing and preventing bromide rash has been asserted by several observers, and lately Dr. Gowers has published illustrative cases (Lancet, i., 1878).

Undue Reflex Action, Vomiting

In a number of cases, somewhat dissimilar in symptoms, but connected with exaggerated reflex action, whether spasmodic in character or exhibiting altered function or secretion, the bromides prove useful. In reflex vomiting, as that of pregnancy, or even in sea-sickness, and sometimes in cerebral vomiting, they give relief. Five to ten grain doses, if retained, are often sufficient; but, in obstinate cases connected with pregnancy, 1/2 to 2 dr. doses have been successfully given by injection (Lancet, i., 1874, p. 770). Laborde has seen it useful in the vomiting of various gastro-intestinal disorders.

Preparation And Dose

Potassii Bromidum: dose, 5 to 20 gr. and upwards (v. pp. 106, 107, 109). Ammonii Bromidum: dose, 2 to 20 gr. and upwards.

Concerning the different bromides, we may here briefly state that the potassium salt is in the most common use, but contains the least bromide of the alkaline salts (v. pp. 97, 98), and is more depressing to the circulation.

The sodium salt I consider rather more powerful as a bromide, though all observers are not agreed on this point. It is less depressing, and is more easily assimilated (Clymer: Medical Times, i., 1872, p. 238).

The ammonium salt possesses some of the stimulant characters of its base, which is liberated by decomposition. Its action is said to be more rapid, but also more evanescent (Begbie). The lithium salt has been found to relieve some epileptics better, and in smaller doses than the potassium salt, and to give sleep well (Gibb, 1864; Weir Mitchell: American Journal, ii., 1870). The calcium salt is said to be more active than that of potassium, 22 gr. of the former causing sleep when the latter failed (Hammond). The compound with camphor (monobromated camphor) reduces heart-action and lowers respiration and temperature like the other alkaline bromides; it is efficient as a sedative in less dose - 3 to 6 gr. In the compounds with morphia and quinine, Dr. Richardson expects to secure the sedative and tonic effects of these drugs without the unpleasant cerebral symptoms which sometimes accompany them (Medical Times, i., 1871, p. 413). I have found them useful. Bromhydric acid is said to produce most of the good effects of alkaline bromides with less depression, and to be more readily borne (C. Wade, M. Fothergill). Its real value is, however, not yet proved.

Therapeutical Action (External)