The Iodide of Potassium, or Kali hydriodicum, does not, like the Bromide of Potassium, act on the higher tissues of the body. It seems to affect more the lowest tissues, as the fibrous, acting particularly on the periosteum and the connective tissue wherever they may be found. It attacks the nervous tissues ultimately, probably by involving the neuroglia. The tendency of the drug is to produce infiltration, so that when it is thoroughly indicated you will almost always find an oedematous or infiltrated state of the part affected. Some of the symptoms produced by Iodide of Potassium are due directly to the Iodine which it contains. For instance, what is known as iodine intoxication may be developed by the drug. The patient exhibits a great deal of anxiety about the heart, the face is flushed, the head is hot, and the patient very talkative; in fact, he acts pretty much the same as would a man under the partial influence of liquor.
The headache which Kali hydriodicum causes is one of the external head, probably from the action of the drug on the aponeurosis of the occipito-frontalis muscle, because there appear hard lumps like nodes on the scalp and these pain excessively. This may be a remote symptom of syphilis or of mercurialization, or it may appear in a patient with the rheumatic diathesis.
In affections of the eyes Kali hydriodicum is called for principally by the violence of the symptoms, especially in syphilitic iritis after the abuse of mercury. Now, if mercury has not been abused, I do not consider the Iodide of Potassium to be the best remedy. If there is any best remedy for iritis it is MERCURIUS CORROSIVUS. We may also use Kali hydriodicum for inflammation involving both choroid and iris, the result of syphilis. More externally we find pustular keratitis, with chemosis, especially after the abuse of mercury.
Coming next to the nose, we have the following indications for the Iodide of Potassium : Coryza or catarrh, occurring repeatedly in patients who have been mercurialized; every little cold or exposure, or every damp day causes the nose to become red and swollen; an acrid watery discharge flows from it, and the eyes smart and lachrymate, and become puffed. The patient is alternately chilly and hot, the urine is high-colored (as the patient expresses it) and scanty, and there is usually some sore throat. Every exposure provokes a return of these symptoms.
Kali hydriodicum also cures this thin excoriating nasal discharge when it appears as an inheritance from syphilitic parents. The ozaena which it cures is either scrofulous, syphilitic, or mercurial, or a combination of all of these. The discharge may be either thin and acrid, or else thick, green, and offensive, and attended with burning sensation in the nose and even perforation of the nasal bones.
Next, the action of Iodide of Potassium on the lungs and heart: It is not a little singular that all the preparations of Mercurius produce sharp, stitching pains through the lungs (through either the right or left lung, and shooting in different directions), and that the very best antidote to mercury also produces stitching pains through the lungs, particularly through the sternum to the back; worse from any motion. Now, there are two exactly opposite conditions in which Iodide of Potassium is to be here thought of. One of these is in pneumonia, in which disease it is an excellent remedy when hepatization has commenced, when the disease localizes itself, and infiltration begins. In such cases, in the absence of other symptoms calling distinctively for Bryonia, Phosphorus, or Sulphur, I would advise you to select either Iodine or Iodide of Potassium. It is also called for when the hepatization is so extensive that we have cerebral congestion or even an effusion into the brain as the result of this congestion. Now, the symptoms in these cases are as follows: First, they begin with very red face, the pupils are more or less dilated, and the patient is drowsy; in fact, showing a picture very much like that of Belladonna. You will, in all probability, give that remedy, but it does no good. The patient grows worse, the breathing becomes more heavy, and the pupils inactive to light, and you know then that you have a serious serous effusion into the brain, which must be checked in a short time or the patient dies. Why did not Belladonna cure? He who would prescribe by the symptoms alone in this case would fail, because he has not taken the totality of the case. The trouble did not start in the brain. The cerebral symptoms are secondary to others. What, then, is the primary trouble? You put your ear to the patient’s chest, and you find one or both lungs consolidated ; hence, the blood cannot circulate through the lungs as it should, and the different organs in the body become congested. So until you have proved that Belladonna has produced such a condition you cannot expect it to do any good.
Another condition in which we may use Iodide of Potassium is in pulmonary oedema, thus again showing you the infiltration producible by the drug. This is almost always, as you know, a secondary trouble. The expectoration looks just like soapsuds, only it is apt to be a little greenish.
We may also have Kali hydriodicum indicated in phthisis pulmonalis, particularly if there is present this same sort of frothy expectoration, night-sweats, and loose stools in the morning. The cough is of a violent racking, tearing character, and is worse in the morning, thus keeping up the character of the potash salts, to have aggravation of chest symptoms from two to five o’clock in the morning. I may say that these symptoms of the lungs are often consecutive to Bright’s disease, in which disease Kali hydriodicum may be the remedy.
YERBA SANTA is used by eclectics for phthisis of catarrhal origin. It is used empirically. There is a gentleman who has a tendency to catarrhal asthma, with thickening of the bronchial tubes and constant oppression of breathing. I treated him for a year. Sulphur seemed to be indicated, but was given with only partial relief. Finally, I gave him Yerba santa in the tincture. It so far relieved him that every morning he coughed up a quantity of sputum, and there then followed a freedom of breathing he had not had for years.
The action of Kali hydriodicum on the heart is also characteristic. It produces a horrible smothering feeling about the heart, awakening the patient from sleep and compelling him to get out of bed. This symptom is also found under LACHESIS, KALI BICHROMICUM, LACTUCA, EUPHRASIA, GRAPHITES, and some others.
It is also useful for repeated attacks of endocarditis or pericarditis of rheumatic origin. There are sharp, darting pains in the heart, worse from any motion, and particularly bad from walking.
In diseases of the spine, you will find Kali hydriodicum indicated by these symptoms: Feeling as if the small of the back were being squeezed in a vice; bruised pain in the lumbar region and difficulty in walking; spinal meningitis with oedema or exudation, particularly when of syphilitic origin.
When gummatous tumors involve the nervous tissues, Iodide of Potassium is your only hope.
It may also be of use when rheumatism involves the spine and paraplegia results. In these cases I think that it is the neuroglia that is attacked.
It may still further be used in rheumatism of the joints, particularly of the knee. The knee-joint is swollen and has a doughy feel; here again you see the tendency of the remedy to produce infiltration of tissue. There is no fluctuation to be detected. The skin about the inflamed joint is apt to be spotted, and the pains are of a gnawing, boring character, and are worse at night.
In sciatica, you may give Kali hydriodicum when the pains are worse at night, and from lying on the affected side, and when the trouble is of mercurial or syphilitic origin.
You will find that the Iodide of Potassium will help you in the treatment of the so-called contracted kidney, especially when of mercurial origin.
Iodide of Potassium, like all the potash preparations, produces an eruption of a papular or of a pustular character. Especially do these appear on the scalp and down the back; when they heal they leave a cicatrix.
You may also remember Iodide of Potassium as a remedy for tertiary syphilis, particularly rupia.
The best antidote to Iodide of Potassium is HEPAR.