Euthyrox: what is it, indications and side effects - medical - 2023



The thyroid gland is a vital part of the endocrine system and, therefore, of the entire body. Located in the neck, this small structure of about 5 centimeters and just 30 grams, produces thyroid hormones, which are essential for the metabolism to go at the proper speed.

Thyroxine (T4) and triiodothyronine (T3) are the main thyroid hormones and are needed in just the right amounts to regulate energy levels (high during the day and low at night), build muscle, repair tissues, absorb nutrients, limit cholesterol levels, keep skin healthy And a long etcetera.

Unfortunately, thyroid disorders, generally due to genetic causes, cause a dysregulation in the synthesis of these hormones. Hypothyroidism is the most common disorder and develops when not enough T4 and T3 hormones are produced, causing symptoms that threaten a person's quality of life (and health).

As this hypothyroidism is generally due to genetic disorders, there is no cure as such. Fortunately, pharmacology has allowed the development of hormonal replacements through medications that, once in the body, take on the role of the hormones that we lack. In this sense, Euthyrox is one of the main treatment options for hypothyroidism and other thyroid problems. And today we will learn everything there is to know about him.

  • We recommend you read: "The 6 differences between hyperthyroidism and hypothyroidism"

What is Euthyrox?

Euthyrox is a drug whose active ingredient, levothyroxine, is a synthetic form of thyroxine, one of the most important thyroid hormones. In this sense, levothyroxine, once it has entered the body through the drug, has exactly the same effect as natural thyroxine.

In fact, the body is unable to distinguish between synthetic levothyroxine and T4, that is, thyroxine. In addition, in the different organs of the body, this active principle is also transformed into T3, so we end up recovering the hormones we need.

Absorbed in a few hours in the intestine, Euthyrox remains in the bloodstream in adequate amounts for up to 9-10 days, during which time it performs the same functions as thyroid hormones, which is why it receives the title of "hormone replacement."

In this sense, Euthyrox is a drug that can only be obtained with a prescription and that is used to treat mainly hypothyroidism, although it is indicated for other situations that we will discuss below.

Chemical structure of levothyroxine, the active principle in Euthyrox.

When is its use indicated?

Its use is especially indicated in patients suffering from hypothyroidism or other health problems related to the thyroid gland. If there is no problem in the thyroid gland, it should not be taken under any circumstances, as an excess in the amount of thyroid hormones leads to the development of another equally serious disease, which is hyperthyroidism.

For this reason it should only be taken under the express indication of a doctor after it has been diagnosed hypothyroidism. In people with this endocrine disorder, which, as we have mentioned, usually has a genetic origin, Euthyrox is one of the best options to restore normal thyroid hormone values.

When T4 and T3 values ​​are too low, the risk of developing the following symptoms and complications increases: muscle stiffness, sensitivity to cold, increased predisposition to have high cholesterol levels (hypercholesterolemia), weight gain, decreased heart rate ( affects cardiovascular health), drowsiness, tiredness and weakness, sleeping more hours than normal, joint pain, constipation, swelling of the face, hoarseness and even greater chances of suffering from depression.

In this sense, Euthyrox is useful to recover endocrine health and restore hormonal values ​​in people with hypothyroidism, which is usually due to the fact that, due to genetic factors, the immune system attacks the thyroid, preventing it from synthesizing the necessary amounts. of hormones to properly regulate metabolism.

Beyond this hypothyroidism, Euthyrox is indicated for other thyroid problems (but never for hyperthyroidism, as there would be too high amounts of thyroid hormones), such as to treat goiter (enlargement of the thyroid gland due to lack of iodine in the diet, which does not usually happen since we eat with salt), prevent the development of goiter after surgery (since diets are followed almost without salt) or to stop growth of tumor in patients with thyroid cancer, which, with its 567,000 new cases diagnosed annually in the world, is the 10th most common cancer. With proper treatment (including Euthyrox), his survival is almost 100%.

  • We recommend you read: "Survival rates for the 20 most common cancers"

In summary, the main indication for the use of Euthyrox is to treat hypothyroidism, an endocrine disorder that affects between 4% and 8% of the world population, which means that in the world there could be up to 560 million people that, at some point, they might need this medicine.

Similarly, but to a lesser extent, Euthyrox can be prescribed both to prevent and treat goiter, which is an enlarged thyroid due to a lack of iodine (the precursor of thyroid hormones), and to improve the prognosis of patients with thyroid cancer.

What side effects can it generate?

While taken only when and as directed, Euthyrox has few side effects. The problem comes if we take it when there is no problem in the thyroid gland, as this extra supply of hormones can cause hyperthyroidism, a disorder that consists of too many thyroid hormones flowing through the circulatory system.

  • To know more: "The 10 most common endocrine diseases (causes, symptoms and treatment)"

This situation can lead to the following symptoms: weight loss, tachycardia (heart rate accelerates), difficulty falling asleep, tendency to anxiety, irritability, color sensitivity, skin that is too thin, tremors, stress, hair fragility ( with a tendency to fall) and nervousness, fever, menstrual disturbances, sweating, diarrhea, headache, chest pressure, muscle weakness, cramps ...

Therefore, the adverse effects come if Euthyrox is taken when there is actually no thyroid problem or when the doses are not respected and it is consumed more than necessary. As it is a hormonal replacement and does not alter the normal physiology of the body (as do analgesics, anti-inflammatories, antidepressants ...), its consumption, as long as it is in the doses indicated by the doctor, does not have adverse effects.

Therefore, beyond a possible allergic reaction, the consumption of Euthyrox does not cause significant side effects. A small percentage of people show rejection or low tolerance, so they can develop the symptoms that we have seen even respecting the doses, but this only happens in isolated cases.

In the vast majority of people who take it only if there is a problem of hypothyroidism (or goiter or thyroid cancer) and respect the doses, Euthyrox does not cause physical or psychological problems. In short, the side effects they do not come from the Euthyrox itself, but the possible excess of thyroid hormones that its irresponsible consumption can lead to.

Euthyrox 100 micrograms in tablet form is the most prescribed.

Euthyrox questions and answers

Having understood its method of action, in which cases it is indicated (and in which not) and that as long as the doses are respected it does not present important side effects, we already almost know everything there is to know about this drug. Anyway, as it is understandable that doubts remain, we have prepared a selection of the most frequently asked questions with their respective answers.

1. What is the dose to take?

Euthyrox is sold in tablet form, although it comes in more than ten different doses, ranging from 25 micrograms to 200 micrograms. Depending on the degree of hypothyroidism, the doctor will prescribe a higher or lower dose. The important thing is that it should be taken a single tablet a day, that is, the daily intakes should be administered in a single dose.

2. How long does the treatment last?

In hypothyroidism, treatment lasts for lifetime, because you always have to maintain adequate hormonal levels. In the case of goiter or thyroid cancer, until the disease resolves. The first 2-4 weeks will be given a low dose, between 25 and 50 micrograms. Afterwards, the maintenance dose will be between 100 and 200 micrograms.

3. Does it generate dependency?

There is no evidence that the consumption of Euthyrox, even if it is taken for the whole life, generates neither physical nor psychological dependence. It is a medicine no addictive power.

4. Can I become tolerant of its effect?

Similarly, there is no evidence that, no matter how long the treatment lasts, the body gets used to it. Euthyrox maintains its effectiveness intact throughout life.

5. Can I be allergic?

As with all medicines, yes, there is a possibility that you are allergic, either to the active ingredient or to the other compounds. For this reason, in the event of skin or respiratory reactions, a doctor should be consulted immediately.

6. Can older people take it?

Yes but the starting dose will be lower. In other words, during the first four weeks, a dose of about 12.5 micrograms will be taken, which will be gradually increased, at the rate of 12.5 more micrograms per day every two weeks. As soon as the maintenance dose is reached, they can take it under the same conditions as other adults, although always trying to make it the lowest possible dose.

7. Can children take it?

It is not common for babies and children under 15 years of age to express hypothyroidism, but if so, it can be taken, but always adjusting the dose depending on the weight. To do this, you will have to consult a pediatrician and always review the prospectus.

8. In what cases is it contraindicated?

In addition to, obviously, people who do not have hypothyroidism (what to say that those who have hyperthyroidism cannot take it under any circumstances), Euthyrox is contraindicated in people who have hypothyroidism but also suffer from adrenal insufficiency (the adrenal glands stop producing hormones ), pituitary insufficiency (the pituitary stops producing hormones), thyrotoxicosis (very high levels of thyroid hormones in the blood), have recently had a heart attack or inflammation or have an allergy to any of the components of the medicine.

Beyond this, it has no major contraindications. In any case, it will be the doctor who, after reviewing the medical history, prescribes or not Euthyrox. So there is nothing to worry about.

9. How and when should it be taken?

Euthyrox should be taken in a single dose in the morning on an empty stomach, at least 30 minutes before breakfast. It is preferable to take it with half a glass of water to promote absorption.

10. Does it interact with other medications?

Yes, with several and in different ways. It does not interact with most analgesics and anti-inflammatories, so in this aspect there is nothing to worry about. Anyway, it does, for example, with antidiabetics. Therefore, it is always important not to self-medicate if you are taking Euthyrox and to always consult a doctor before combining medications.

11. Can it be consumed during pregnancy? And during breastfeeding?

As long as the marked daily doses are respected, there is no problem (neither for the mother nor for the fetus or the baby) in taking Euthyrox during pregnancy or breastfeeding.

12. Can I drive if I am undergoing treatment?

No scientific studies have been done to show whether it affects driving ability. Anyway, considering that it is a hormone replacement, it is not expected to do so. So, yes, there is no problem. You can drive and operate heavy machinery.

13. Are overdoses dangerous?

If you have taken more Euthyrox than you should, you may experience symptoms similar to hyperthyroidism. But beyond this, which goes on for a few hours, It's not dangerous. Of course, you have to watch. Nothing happens as long as it is an isolated incident.

Overdoses are only dangerous and you should consult your doctor quickly if you suffer from a neurological disease or psychotic disorder.

14. What happens if I miss a dose?

As long as it is a punctual forgetfulness, nothing happens. Yes, it is much better skipping the missed dose than make up for it with a double dose. You just have to take the normal dose the next morning.

15. Can I drink alcohol if I am in treatment?

Yes. Euthyrox does not irritate the gastrointestinal tract, so alcohol can be drunk while undergoing treatment. It neither interferes with its action nor increases the risk of side effects. Of course, obviously, you have to make a responsible consumption.