Euthyrox refers to levothyroxine sodium tablets, and taking too many levothyroxine sodium tablets may make total thyroxine high. Levothyroxine Sodium Tablet belongs to the class of thyroid hormone medications that can be used to treat hypothyroidism. The drug is a thyroid hormone replacement therapy, and when taken appropriately, it can help to maintain the body’s thyroid hormone levels in a relatively normal range, while overdose may cause the total thyroxine to be higher than normal. Overdose may lead to arrhythmia, tachycardia, angina and other adverse reactions. Contraindications to taking levothyroxine sodium tablets include hypersensitivity to the product and its excipients; untreated hypoadrenalism, pituitary insufficiency, and thyrotoxicosis; acute myocardial infarction, acute myocarditis, and acute total carditis. Patients should take levothyroxine sodium tablets correctly under the guidance of a doctor, and should not change the dosage on their own.