This section is from the book "Materia Medica And Therapeutics: An Introduction to the National Treatment of Disease", by John Mitchell Bruce. Also available from Amazon: The pharmacology and therapeutics of the materia medica.
A liquid non-metallic element.
Source. - Obtained from Bitter, and from some Saline Springs.
Characters. - A dark brownish-red very volatile liquid, with a strong disagreeable odour; solubility, 1 in 30 of water.
Impurity. - Iodine; detected by starch test.
Not given internally.
From Bromum are made:
Potassii Bromidum. See Potassium. Dose, 5 to 30 gr.
Externally bromine is a powerful irritant and escharotic. Its local use is confined to the treatment of cancer of the cervix uteri (1 in 5 parts of rectified spirit). The bromides have no such irritant action unless in highly concentrated solution; nor are they absorbed from the unbroken skin.
The bromides taken continuously for a time in full doses, or applied in strong solution to the throat, are said to reduce the sensibility of the fauces, so that the reflex movements of the parts, such as swallowing, vomiting, cough, etc., are not easily excited; and they may therefore be employed previous to important examinations or operations in connection with the larynx, or in excessive irritability of the parts. The bromides have but little effect of an irritant kind on the stomach or bowels, so that large doses (20 grains thrice a-day for years) may be readily borne. The greatest care must always be taken, however, to preserve the digestion and regularity of the bowels, in cases where bromides are continuously taken.
Bromide of potassium enters the blood unchanged, where it is probably converted into the sodium salt by double decomposition with the chloride of sodium. For a moment it may be free in the blood, but no special action or therapeutic application can be referred to this circumstance.
The bromides pass through the organs as such or as bromide of sodium, and have a very definite specific action upon them, which, speaking generally, is one of depression.
The nervous system is specially affected. Loss of reflex excitability in connection with all the sentient surfaces of the body follows the administration of full medicinal doses. This result is due partly to depression of the peripheral (sensory) nervous filaments, but -chiefly to reduced activity of the nervous centres in the brain and cord. At the same time the motor nerves are also soothed, and the muscular power (which we may conveniently consider along with the nervous), is much weakened. The phenomena of this general nervo-muscular depression are as follows, beginning with the highest centres: (1) The bromides lessen mental activity, readiness to react to emotional stimuli, and sensibility and irritability of mind generally, thus inducing a condition of brain favourable to the advent of sleep. They are thus indirect hypnotics, not acting like opium and chloral, but so reducing the patient's sensibility of his surroundings, bodily condition, or circumstances, as to prevent distraction, and allow natural sleep to intervene. It is uncertain whether the bromides act upon the nerve cells directly, or upon the cerebral blood-vessels. The soothing and hypnotic effects of the bromides are very extensively employed in restlessness and sleeplessness from mental strain, whether emotional or intellectual, in the acute specific fevers when similar symptoms are urgent, in acute alcoholism, and in mania. In the three last conditions a certain amount of chloral or opium may be advantageously combined with the bromides. Bromide of lithium, the most active hypnotic of the bromides, will sometimes remove the insomnia of gout. The most important application of the soothing action of the bromides is in epilepsy, which is now almost exclusively treated with these salts, unless they be contra-indicated. Hysteria, infantile convulsions, whooping-cough, general "nervousness," hypochondriasis, and the low despondent condition so common in women with uterine irregularities, are also relieved by bromides, although not with the success obtained in epilepsy.
The great vital centres of the medulla are depressed by bromides. Respiration becomes slower and is weakened, whence possibly part of the value of the drug in whooping-cough. The heart is also slower and weakened in its action; chiefly, however, by depression of its nervo-muscular substance, not of the cardiac centre. Bromides are of much service, therefore, in nervous disorder of the heart, especially in hysterical, dyspeptic, and alcoholic subjects. The direct effect of these drugs on the vessels is unsettled; as a whole, the tension is reduced.
The spinal centres, and spinal nerves and muscles, are all depressed by the bromides, the former so much so that the convulsions of strychnia poisoning cannot be induced, and the two drugs are so far physiological antagonists. In such a case and in tetanus the bromides may be given, but are neither rapid nor powerful enough to be trusted to alone.
The temperature is lowered by bromides, but not to an extent of much practical value.
The ovarian and uterine functions are quieted, and monorrhagia relieved, by the same drugs.
The bromides appear in the secretions within a few minutes after their administration, being eliminated by the kidneys chiefly, by the salivary glands, mammas, skin, and all mucous surfaces. In passing through these excreting organs, the bromides break up and set free bromine, which exerts a remote stimulant effect on the parts. The composition of the urine is irregularly disordered; but not in a manner that can be turned to therapeutical account. The skin is markedly affected, a characteristic acne-like eruption appearing, or other forms of skin disease, which are familiar in epileptics consuming large quantities of the drug. Cough is occasionally set up, and conjunctivitis may also occur. The interest to the therapeutist of all these remote effects of the bromides lies in their pre-vention, if possible, in cases where the drugs have to be steadily taken for an indefinite time, an end which may sometimes be secured by combining them with arsenic.