Thyroxine tablets should be taken from “small” doses, adjusted once every 1-2 weeks, and thyroid function should be reviewed every 3 months. People with low thyroid function need to take thyroxine tablets to supplement the lack of thyroxine secretion. Xu Chun, deputy chief physician of the endocrinology department of the General Hospital of the Armed Police, pointed out that thyroxine tablets must be taken in small doses to start with. Thyroxine tablets are hormonal drugs and overdose may cause accelerated heart rhythm and even heart failure. Therefore, an electrocardiogram should be done before taking thyroxine tablets. Whether you are a child or an adult, you should start with a small dose of thyroxine tablets and gradually increase the dosage thereafter until you meet your body’s needs. In addition, the dose of thyroxine tablets is related to body weight, and the general human body needs a dose of 1.7 mcg/kg. Children’s light weight and poor drug resistance make it even more important to control the dose. In general, the dose of thyroxine tablets should be adjusted once in 1-2 weeks. If, after taking the drug, the patient’s appetite improves, constipation disappears, abdominal distension is reduced without pallor, palpitations, excessive sweating, weakness and other symptoms of hyperthyroidism, and thyroid function is tested to be normal, then the dose can be taken as a maintenance dose and taken for a long time at this dose. Thereafter, patients should have their thyroid function checked every 3 months or 6 months in order to adjust the dose. If symptoms such as irritability, excessive sweating, abdominal pain, diarrhea, or significant weight loss occur during the course of medication, the dose may be too high and the thyroid function should be checked at the hospital and the dose reduced as appropriate. If a child with hypothyroidism has accelerated growth and development after taking thyroxine tablets, protein and various vitamins and minerals should be supplemented. There are two main types of drugs that replace thyroid function: one is thyroid tablets, which are extracted from the thyroid tissue of pigs and are cheap but contain more impurities. The other is levothyroxine tablets, which are synthesized through genetic engineering and are more commonly used clinically.