What are the effects of hypothyroidism and long-term use of levothyroxine on the body?

A friend left a message to Hua Zi, asking about hypothyroidism (hypothyroidism), and he needs to take levothyroxine for life without interruption. He was worried that taking the medicine for so long would have other effects on the body. Is it really okay?

Hua Zi said that people with hypothyroidism mean that the thyroid function is insufficient and cannot secrete enough thyroxine for the body to use, which will affect the nervous, cardiovascular, blood lipid, metabolism and other systems. At this time, continuous exogenous thyroxine supplementation is required to maintain the normal operation of the body’s various systems, which is also called replacement therapy.

One, completely consistent with human thyroxine

In substitution therapy, the more similar the drugs used are to the substances produced by the body, the fewer adverse reactions. And levothyroxine is exactly the same as tetraiodothyronine (T4) produced by the human thyroid gland, so long as the dose is reasonable, it will not cause adverse effects on the body.

Most causes of hypothyroidism are permanent and cannot be reversed, so levothyroxine needs to be taken continuously. After taking levothyroxine, it can completely replace the role of human endogenous T4, and it will be converted into triiodothyronine (T3) to exert physiological activity. Good security.

Second, the dose of levothyroxine should be controlled reasonably

The biggest problem you can encounter while taking levothyroxine is an inaccurate dose. Because thyroid hormone is related to the growth, development and metabolism of the human body, when taking levothyroxine, try to simulate the secretion of normal human thyroid hormone, neither more nor less.

Excessive doses can cause symptoms of hyperthyroidism (hyperthyroidism) such as tachycardia, flushing, heavy sweating, headache, and insomnia. If the dose is insufficient, the symptoms of hypothyroidism, such as chills and fatigue, low mood, elevated blood lipids, dry skin, and slow response, will not be relieved.

Each person’s physical condition is different, and the residual thyroid function is also different. Individualized medication is required, and thyroid function is regularly reviewed for dose adjustment.

Third, why some patients with hyperthyroidism also use it

A patient with hyperthyroidism has asked Hua Zi why the doctor’s medication regimen for him also contains levothyroxine, will it cause the symptoms of hyperthyroidism to worsen? Hua Zi said, Levothyroxine does not directly treat hyperthyroidism in patients with hyperthyroidism, but should be combined with antithyroid drugs for adjuvant therapy.

For example, when patients with hyperthyroidism use methimazole, propylthiouracil and other drugs for antithyroid therapy, they may experience symptoms of hypothyroidism after the drug, but the drugs are not easy to remove Divided into smaller doses, at this time, a small amount of levothyroxine can be used together to adjust thyroid function to a normal state.

4. Precautions when taking medicine

The secretion rule of human thyroid hormone is high during the day and low at night, so taking levothyroxine in the morning is closest to the natural law. Levothyroxine needs to be taken on an empty stomach and at least 30 minutes after taking a meal. However, many people need to rush to work in the morning and may not be able to leave enough time for an empty stomach. They can also take the medicine on an empty stomach before going to bed.

Levothyroxine needs to be taken on a daily basis without interruption, If a dose is missed, it is recommended to take a double dose at the next dose. If you miss a dose for several days in a row, you must take double the dose on consecutive days until the missed dose is made up. In the process of making up the double dose, if you have symptoms of hyperthyroidism, you should consult your doctor in time to adjust the dose.

To sum up, people with hypothyroidism need to take levothyroxine regularly for a long time, and most people need lifelong maintenance treatment. Levothyroxine is exactly the same as T4 produced by the human body, and as long as the dose is reasonable, there are usually no adverse reactions.

It is recommended to re-examine once every two weeks in the initial stage of medication, once in 1 month after the condition is stable, and once in 2-3 months after lasting for half a year. The medicine should be used under the guidance of a doctor. If you have any doubts about the medicine, please consult your doctor or pharmacist. I am Huazi, a pharmacist. Welcome to follow me and share more health knowledge.