How L-thyroxine works
The thyroid gland produces the hormones triiodothyronine (T3) and thyroxine (T4), which primarily regulate metabolic processes. In the case of a hormone deficiency, these processes can no longer run smoothly. This leads to complaints such as fatigue, tiredness or depressive moods.
L-thyroxine: effect
When is L-thyroxine used?
L-thyroxine is mainly used in the following cases:
- in hypothyroidism (underactive thyroid gland)
- @ in case of thyroid enlargement (goiter)
- after thyroid surgery
- @ in hyperthyroidism (hyperthyroidism) in combination with thyrostatic drugs (thyroid blockers)
L-thyroxine in hypothyroidism
Deficient hormone production in the thyroid gland can be congenital or acquired. Very often, hypothyroidism develops only in adults in the course of life. Usually the reason is an inflammation of the organ (thyroiditis such as Hashimoto’s thyroiditis). In addition, surgery or radioiodine therapy can also be the cause of hypothyroidism.
L-thyroxine for thyroid enlargement (goiter)
L-thyroxine interrupts this growth process. The hormone is often prescribed together with iodine to treat iodine-deficient goiter particularly effectively. This therapy can sometimes prevent the need for surgery to reduce the size of the enlarged thyroid gland.
L-thyroxine after thyroid surgery
Sometimes it is even necessary to remove the thyroid gland completely. Then the lifelong intake of artificial thyroxine is mandatory, since the body can no longer produce the important active ingredient itself.
In addition, L-thyroxine is used after the surgical removal of a thyroid tumor. After the operation, hormone production is also often reduced, which must be compensated for by taking L-thyroxine.
L-thyroxine for hyperthyroidism
Hyperthyroidism is treated with so-called thyrostatic drugs (thyroid blockers). Sometimes L-thyroxine is also prescribed.
L-thyroxine for weight loss?
People with hypothyroidism often gain weight unintentionally without changing their eating habits. L-thyroxine compensates for the hormone deficiency and thus combats the symptoms of hypothyroidism, which also means weight gain.
Never take L-thyroxine without a doctor’s recommendation. Above all, L-thyroxine is not suitable for preventing weight gain.
L-thyroxine: Alternative forms of treatment?
Properly dosed, L-thyroxine is very well tolerated. Some patients nevertheless look for an alternative, for example because of possible interactions with other medications.
Naturopaths see other possibilities of treatment such as Schüßler salts or homeopathic substances. However, their effect is not scientifically proven.
A deficiency of vital thyroid hormones must absolutely be treated by conventional medicine. Alternative healing methods such as homeopathy should only be used as an adjunct.
How L-thyroxine is used
L-thyroxine: Dosage
The optimal hormone level varies from person to person. Therefore, the necessary L-thyroxine dose is also individual. The treating physician determines the dose and also the duration of treatment.
Therapy usually starts with a low dose of L-thyroxine – 25 micrograms is common at the beginning. If this is not sufficient, the dose can be gradually increased to L-thyroxine 50, 75, 100 or L-thyroxine 125 micrograms. The maximum dose is 200 micrograms per day.
During therapy, the doctor regularly checks the blood values to track the thyroxine level in the blood. In this way, he can see whether the current dosage is sufficient or whether it is too high or too low and therefore needs to be adjusted. This phase of dose adjustment can take up to several months. However, once patients have been correctly adjusted, their symptoms usually improve rapidly.
L-thyroxine: intake
Doctors usually recommend taking L-thyroxine once a day in the morning, about 30 minutes before breakfast on an empty stomach. Swallow the medication with water only. In particular, avoid taking L-thyroxine with coffee or calcium-containing foods such as milk or yogurt! This is because these foods bind the active substance and thus delay its absorption in the intestine.
If you forget to take L-thyroxine once, you do not need to make up the dose. Then simply swallow – according to your treatment schedule – the next regular dose at the scheduled time.
Discontinue L-Thryroxine
This also applies to thyroiditis: Discontinuing L-thyroxine is usually not an option in Hashimoto’s thyroiditis. This is because the autoimmune disease destroys thyroid tissue in stages and irreversibly. The remaining tissue can only produce L-thyroxine to a limited extent, so the hormone must be supplied permanently.
What are the side effects of L-thyroxine?
Once the dosage is adjusted correctly, L-thyroxine is usually well tolerated. Nevertheless, as with any drug, side effects may occur with L-thyroxine, especially during the initial phase of therapy. For example, possible side effects include:
- palpitations/heart palpitations
- Insomnia
- Headache
- nervousness, restlessness
- Increased intracranial pressure (mainly in children)
- cardiac arrhythmia
- increased sweating
- skin rash
- Gastrointestinal complaints
- Tremor
- Menstrual cramps
- Weight loss
Another side effect of L-thyroxine affects menopausal women: In them, L-thyroxine increases the risk of osteoporosis. In addition, water retention may occur due to L-thyroxine. However, this happens relatively rarely.
L-thyroxine: overdose
In the event of an acute, significant overdose of L-thyroxine, follow these recommendations:
- do not force vomiting
- do not drink water
- contact poison control center, hospital outpatient clinic or attending physician
L-thyroxine: underdose
If the L-thyroxine is underdosed, the symptoms of thyroxine deficiency, such as tiredness and fatigue, remain at least in a weakened form.
If you notice that your symptoms do not (completely) disappear despite taking L-thyroxine, you should inform your doctor. He will then increase the dose if necessary.
When should L-thyroxine not be taken?
Patients who are allergic to the active substance must not use L-thyroxine. Other contraindications are:
- acute myocardial infarction, acute myocarditis, acute inflammation of the heart wall (panicarditis)
- untreated dysfunction of the pituitary gland
Pregnant women may and must continue to take prescribed L-thyroxine. However, the dose may need to be adjusted as hormone requirements may increase during pregnancy. It is not allowed to take L-thyroxine and thyroid blockers at the same time during pregnancy.
L-thyroxine: interactions
- Phenytoin (drug for epilepsy, cardiac arrhythmias and nerve pain)
- Salicylates (pain reliever and antipyretic)
- Dicumarol (anticoagulant)
- Furosemide (diuretic)
- Sertraline (antidepressant)
- Chloroquine and proguanil (antimalarials)
- Barbiturates (sleeping pills and sedatives)
- Amiodarone (antiarrhythmic agent)
In addition, the pill may increase the need for L-thyroxine.
Conversely, L-thyroxine can also slow down the effect of other drugs. The artificial hormone can, for example:
- reduce the blood sugar-lowering effect of metformin, insulin or glibenclamide
- @ increase the anticoagulant effect of certain drugs such as phenprocoumon
As a general rule, discuss the concomitant use of L-thyroxine and other medications or dietary supplements with a doctor or pharmacist first.
Where can you get medicines containing L-thyroxine?
L-thyroxine preparations require a prescription. You can get the medication at a pharmacy by presenting a doctor’s prescription.
