How fludrocortisone works
Fludrocortisone is a man-made mineral corticoid.
Mineral corticoids are naturally occurring hormones in the body. They are produced by the adrenal cortex (cortex glandulae suprarenalis) and regulate mineral balance – hence the name mineral corticoids.
Fludrocortisone also acts primarily like the natural mineral corticoids.
The most important endogenous mineral corticoid is aldosterone.
How quickly does fludrocortisone take effect?
The effect of fludrocortisone usually starts after two to three days. It lasts for several days after the end of therapy.
Fludrocortisone: What dosage forms are available?
Fludrocortisone is available in Germany, Austria and Switzerland in tablet form. In Germany, there are also oral drops. In Switzerland, ear drops containing fludrocortisone are also available.
How is fludrocortisone used?
Tablets
Tablets are the most commonly used dosage form of fludrocortisone. The dosage depends on how severely ill patients are and how well they respond to the active ingredient.
The dose can vary from 0.1 milligram once a week to 0.2 milligram once a day. However, dosages of 0.1 milligrams per day for adults and adolescents over twelve years of age are common.
If you develop high blood pressure while taking fludrocortisone, your doctor will probably reduce the dosage to 0.05 milligrams daily.
Solution
The fludrocortisone solution available in Germany contains 0.1 milligrams of active ingredient per milliliter. As with tablets, treating physicians choose a dosage that is individually tailored to the patient. However, the general dose recommendations for children, adolescents and adults remain unchanged.
Ear drops containing fludrocortisone are only available in Switzerland. They contain other active ingredients: Neomycin (antibiotic), Polymyxin (antibiotic) and Lidocaine (local anesthetic). This makes the ear drops suitable for the treatment of inflammatory ear diseases.
You should not use the ear drops for more than ten days.
While instilling the drops into the ear, keep your head tilted to the side. Afterwards, remain in this position for a few minutes so that the drops do not run out of the ear again.
What are the side effects of fludrocortisone?
If fludrocortisone is taken to compensate for missing adrenal hormones, there are usually no side effects.
Other possible side effects of fludrocortisone tablets and solution include headache, high blood pressure, and blurred vision.
Ear drops with fludrocortisone occasionally cause itching and local irritation. However, these are most likely not due to fludrocortisone but to neomycin, which is also included. Aminoglycoside antibiotics such as neomycin are known to cause hypersensitivity reactions.
When is fludrocortisone used?
Fludrocortisone (tablets, solution) is approved for the following indications:
- compensation of missing hormones (substitution therapy) in primary adrenal insufficiency (Addison’s disease)
- Compensation of missing hormones (substitution therapy) in salt wasting syndrome due to adrenogenital syndrome (congenital disorder of hormone formation in the adrenal cortex)
Possible applications of the ear drops available in Switzerland are:
- Acute inflammation of the external auditory canal
- Acute inflammation of the middle ear
- Ear canal furunculosis (purulent inflammation of a hair follicle)
- Allergic skin symptoms in the area of the ear
When should fludrocortisone not be used?
Fludrocortisone as a tablet or solution should generally not be used in the following cases:
- age over 65 years (except for substitution therapy)
- too low blood pressure due to organic heart disease
- high blood pressure
- potassium deficiency
- too high (basic) pH-value of the blood (alkalosis)
- diseases favoring an increase in blood pressure or water accumulation in the tissues (edema) (including coronary heart disease, heart failure, valvular heart disease)
Fludrocortisone ear drops must not be used:
- in case of rupture of the eardrum (perforation of the eardrum)
These drug interactions may occur with fludrocortisone
Fludrocortisone increases the likelihood of potassium deficiency. Too low potassium levels can increase the effect of cardiac glycosides (heart failure medications), leading to side effects.
Like fludrocortisone, laxatives (laxatives) such as bisacodyl and sodium picosulfate increase potassium excretion. Concomitant use therefore increases the risk of potassium deficiency.
Some medicines and foods enhance the effects of fludrocortisone. These include:
- Estrogens (e.g. the contraceptive pill)
- Painkillers from the group of non-steroidal anti-inflammatory drugs (such as ibuprofen, diclofenac and naproxen)
- Glycyrrhizic acid-containing medicines and foods (such as licorice root extract and licorice)
- Cobicistat-containing medicines (cobocistat is an enhancer for HIV medicines)
Conversely, some medicines may decrease the effect of fludrocortisone. These include:
- Rifampicin (antibiotic)
Fludrocortisone during pregnancy and lactation
Pregnant and breastfeeding women may take fludrocortisone for substitution therapy. For other indications, the treating physician must carefully weigh the benefits of the treatment against the possible risks beforehand.
