How betamethasone works
Betamethasone has anti-inflammatory, anti-allergic and immunosuppressive properties. It is 25 to 30 times more potent than its natural counterpart, cortisol.
In the human body, the natural hormone cortisol, also known as hydrocortisone, has multiple effects. Colloquially, the hormone is also called “cortisone”, but this is not correct, as it is the inactivated (ineffective) form of cortisol.
Cortisol has the following functions in the body:
- It increases the production of blood sugar (glucose) in the liver to provide the body with quick energy in stressful situations.
- It accelerates protein turnover – protein breakdown also provides energy.
- It has a depressant effect on the immune system.
Compared to cortisol, betamethasone is less rapidly broken down or inactivated in the body because it cannot be broken down to cortisone by the body’s own enzymes.
Absorption, degradation and excretion
Betamethasone is rapidly absorbed from the gastrointestinal tract after ingestion, reaching peak blood levels after one to two hours. The biological half-life, the time it takes for the effect to drop to half, averages seven hours.
By comparison, the half-life of cortisol is about 1.5 hours.
The liver converts betamethasone into a more soluble compound. This is then excreted in the stool via the bile.
When is betamethasone used?
Betamethasone is applied locally to the skin for skin diseases such as psoriasis, neurodermatitis, allergic or itchy skin reactions (hives). Betamethasone ointment, gel or cream containing the active ingredient as so-called esters are used.
The active ingredient is also combined with other drugs. Thus, the combination with salicylic acid helps to better dissolve existing skin scales, while betamethasone in combination with calcipotriol is often used for the external treatment of psoriasis.
If the betamethasone is to be administered as an injection or taken in liquid form, betamethasone hydrogen phosphate is used. It has much better water solubility than the pure active ingredient. The areas of application for this are even broader. Examples are:
- Fluid accumulation (with swelling) in the brain (cerebral edema)
- Initial treatment of severe skin diseases (see above)
- Rheumatoid arthritis
- Severe inflammatory reactions in the body
However, it is always important to make sure that these are not bacterial inflammations, as the dampening of the immune system by betamethasone could cause infections to flare up especially severely.
How betamethasone is used
The most common form of application of betamethasone is local treatment with the help of betamethasone ointment for skin diseases. Due to its long duration of action, the ointment often only needs to be applied once a day.
In addition, betamethasone tablets are often used, which must be taken according to a doctor’s therapy plan. The dose is generally increased rapidly at first, then kept constant (plateau phase) until the disease has subsided, and then slowly reduced to end the therapy.
The tablets are usually taken in the morning between six and eight o’clock, as the body’s cortisol levels are highest around this time. Taking them after meals improves tolerance in the gastrointestinal tract.
What are the side effects of betamethasone?
The side effects of betamethasone are dose-dependent. At high doses and/or long-term use, the following adverse reactions are possible:
- Diabetes
- Increased blood lipid and cholesterol levels
- Changes in blood electrolyte levels
- Muscle weakness
- Mood swings
- Dizziness
- Digestive problems
- changes in the number of certain blood cells
Many of these side effects can be effectively avoided by administering a dose that is as high as necessary but as low as possible.
What should I watch for when taking betamethasone?
Drug interactions
Betamethasone is broken down in the body by certain enzymes (mainly CYP3A4). Taking other drugs at the same time that stimulate these enzymes reduces the effect of betamethasone.
Such drugs include the antibiotic rifampicin and the epilepsy drugs phenytoin, carbamazepine and phenobarbital.
In combination with ACE inhibitors (antihypertensives such as ramipril, enalapril, lisinopril), blood count changes may occur. Betamethasone can also weaken the blood sugar-lowering effect of oral antidiabetics and insulin.
Non-steroidal anti-inflammatory drugs (e.g., ASA, ibuprofen, naproxen), which are often also taken as headache medications, can lead to increased gastrointestinal bleeding in combination with betamethasone.
Age restriction
Betamethasone is used from birth if necessary.
Pregnancy and lactation
Glucocorticoids such as betamethasone cross the placental barrier and pass into breast milk, which is why they should not be used during pregnancy and lactation.
In medically justified delivery before the actual due date, betamethasone is used to stimulate premature lung development in the unborn child. In this case, it is the drug of first choice.
For local therapy, for example in the form of an ointment, betamethasone can be used both during pregnancy and breastfeeding. However, it should not be applied directly to the breast or nipples during breastfeeding.
How to get medicines containing betamethasone
All medicines containing betamethasone are subject to medical prescription in Germany, Austria and Switzerland.
How long has betamethasone been known?
As early as 1855, the scientist Thomas Addison (after whom Addison’s disease was named, in which there is an underactivity of the cortisol-producing adrenal glands) described a disease that could be successfully treated with an adrenal extract.
The hormone cortisol contained in this extract was identified in 1936 by the research groups led by Kendall and Reichstein. In 1948, it was possible for the first time to produce cortisol in the laboratory.
