BETAMETHASONE: MECHANISM OF ACTION, INDICATIONS, SIDE EFFECTS - MEDICINE - 2024

The betamethasone is a drug of the group of corticosteroids used in humans since the 1960s Despite the development of other glucocorticoids and nonsteroidal antiinflammatory drugs (NSAIDs), betamethasone still is used for various diseases because of its power, effectiveness and safety profile.

It is 300 times more potent than hydrocortisone, a reference drug in the group of corticosteroids. Betamethasone can be used orally, injected and topically both on the skin (creams) and in the eyes (eye drops), and even in the nose through a nasal spray.

Mechanism of action

Betamethasone is a powerful drug with anti-inflammatory and immunosuppressive action with little mineralocorticoid action.

Its main mechanism of action is the activation of a group of proteins known as lipocortins, which in turn inhibit phospholipase A2, responsible for the synthesis of leukotrienes from arachidonic acid, thus blocking the inflammatory cascade.

On the other hand, betamethasone acts directly on leukocytes, which are the white blood cells, inhibiting the release of a series of chemical mediators such as acid hydrolases and interleukins.

Consequences of inhibition of leukocyte acid hydrolases

Leukocyte acid hydrolases are a powerful chemical mediator that recruits white blood cells to the site of inflammation.

By blocking the release of this mediator, betamethasone prevents the accumulation of macrophages in the area and reduces the adhesion of leukocytes to the capillary wall while reducing the permeability of this, thus reducing inflammation.

The goal is to prevent inflammatory cells from accumulating in the area, which will subsequently release more and more chemical mediators, increasing capillary permeability and attracting more cells, ultimately causing edema (fluid accumulation) and inflammation.

Consequences of interleukin inhibition

Inflammation is the product of a series of complex chemical interactions between cells and blood vessels.

These communicate through very specific chemical mediators that "recruit" more inflammatory cells in the area of ​​inflammation and favor the permeability of blood vessels, so that both the fluid and the cells and the same chemical mediators reach the affected area.

Of the wide variety of chemical messengers involved in this process, the main responsible for vascular permeability are histamine, interleukin 1 (IL-1), interleukin 6 (IL-6) and tumor necrosis factor alpha (TNF- alpha).

In this sense, betamethasone acts by inhibiting the secretion of these compounds by inflammatory cells, thus reducing their ability to migrate to the area where the inflammation occurs, as well as the extravasation or leakage of fluid into the compromised area.

Indications for use

Betamethasone has a wide variety of medical indications: from common skin inflammation to the treatment of serious autoimmune diseases such as systemic lupus erythematosus.

The dose, route of administration and duration of treatment will depend on each particular case. Here is a summary of the most common indications:

For skin diseases

Betamethasone is indicated for the treatment of atopic dermatitis, fungal dermatitis, pemphigus, eczema and psoriasis, among other conditions.

In these cases, a compound of betamethasone dipropionate or betamethasone benzoate cream is administered topically, applying a thin layer once or twice a day while massaging the affected area.

For eye diseases

The main indication for ophthalmic drops whose active ingredient is betamethasone is severe allergic conjunctivitis that does not respond to other treatments. However, the list of potential indications is long.

Betamethasone eye drops have application in a wide range of eye diseases, such as uveitis, chorioretinitis, endophthalmitis, Graves' ophthalmopathy, and keratitis, among others.

The treatment interval, duration and combination with other drugs will depend on the clinical conditions of each patient. In all these cases, treatment is delicate and must be supervised by an ophthalmologist at all times.

For diseases of the upper respiratory tract

While there are many treatments available, betamethasone has a place in the management of chronic inflammatory conditions of the upper respiratory tract, such as turbinate hypertrophy, chronic allergic rhinosinusitis, seasonal rhinosinusitis, and in some cases small nasal polyps.

In these cases the route of administration is usually a nasal spray that is applied using a pyramidal scheme; that is to say, it is started 3 or 4 times a day for a week, then the dose is reduced to 2 times a day for 7 more days and thus it is successively reduced until reaching zero.

Treatment with betamethasone for diseases of the upper respiratory tract is always prolonged and should be supervised by a specialist in the area to detect the development of eventual complications.

For autoimmune-immunoreumatological diseases

The main indication for the use of steroids in general, and betamethasone in particular, is for the control of autoimmune and immunoreumatological diseases.

The drug is usually administered orally in the treatment of conditions such as polymyositis, rheumatoid arthritis, systemic lupus erythematosus, exacerbations of multiple sclerosis, polyarteritis nodosa, mixed collagen disease, non-suppurative thyroiditis, and vasculitis, to name just the most common. common.

When oral treatment is not sufficient, betamethasone can be given parenterally (injected), usually intramuscularly. This is the route of choice in certain pathologies, such as graft-versus-host disease.

Again, betamethasone is a delicate drug that should only be administered under strict medical supervision. It is important never to self-medicate because of the health risks that this implies due to inadequate control of the disease or side effects of the medication.

For adrenal insufficiency

Betamethasone can also be used in the treatment of adrenal insufficiency, which is when the adrenal gland does not produce enough hormones.

However, due to its low mineralocorticoid effect, it must be combined with a drug from this group to provide complete treatment.

Other indications

In general, any acute or chronic inflammatory disorder where effective and immediate control of symptoms is required can be treated with betamethasone. For this reason, betamethasone is indicated in crises of bronchial asthma, anaphylactic shock, and chronic bronchitis and urticaria.

Likewise, in those cases where it is sought to prevent inflammation after the administration of a treatment aimed at destroying a tumor or parasite -chemotherapy, treatment of hydatid cysts, etc.- betamethasone can be used as prophylaxis in order to avoid secondary inflammation to treatment even before it occurs.

Finally, betamethasone can be used for fetal lung maturation in cases where there is a risk of premature delivery.

Side effects of betamethasone

Betamethasone is a powerful drug and very effective in treating the conditions for which it is indicated. However, it is not without adverse effects, some mild and others more serious.

There are basically two types of side effects: local and systemic.

Local side effects

When administered topically, especially to the skin and for a long time, there have been reports of:

- Contact dermatitis.

- Hypertrichosis (increase in the amount of hair in the treated area).

- Folliculitis.

- Miliaria.

- Skin atrophy.

- Dryness.

- Hypopigmentation.

Since absorption from local administration sites is minimal, it is uncommon for systemic adverse reactions to occur when the drug is administered locally, as opposed to when the route of administration is oral or parenteral.

Systemic side effects

Brief treatments for acute illnesses - such as bronchial asthma, anaphylactic shock, or hives - are generally not associated with severe or long-lasting side effects.

The most frequent in these situations is gastrointestinal intolerance, which is manifested by the appearance of nausea and vomiting.

However, when the treatment is for a long time, more serious side effects may occur:

- Depression.

- Arterial hypertension.

- Suprarrenal insufficiency.

- Appearance of petechiae (red spots on the skin).

- Tendency to bruise formation.

Likewise, in patients with a history of peptic ulcer disease there is a risk of upper gastrointestinal bleeding, while in those with sensitivity to the drug, allergic reactions may occur.

Betamethasone in children

In children, the use of corticosteroids for a long time is contraindicated unless the benefits ostensibly outweigh the risks, since its administration inhibits the formation of growth plate, negatively influencing the final height of the child.

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