levothyroxine sodium

Levothyroxine sodium is a synthetic version of the thyroid hormone thyroxine (T4) used primarily to treat hypothyroidism, a condition where the thyroid gland doesn't produce enough thyroid hormone. It's also used in the management of thyroid cancer alongside surgery and radioactive iodine therapy[1][2][3]. The medication works by replacing the thyroid hormone that would normally be produced by the body[1][2]. Without adequate thyroid hormone, the body cannot function properly, leading to symptoms such as poor growth, slow speech, lack of energy, excessive tiredness, constipation, weight gain, hair loss, dry skin, increased cold sensitivity, joint and muscle pain, irregular menstrual periods, and depression[1][2]. Levothyroxine sodium is available in multiple formulations including tablets, soft gel capsules, and oral solutions[9]. In the United States, there are several brand-name products including Synthroid, Levoxyl, Levo-T, Unithroid, Tirosint, Euthyrox, and Levothroid[2][6][9]. Generic versions are also widely available, with generic prescriptions accounting for 84.9% of thyroid hormone prescription fills as of 2016[9]. The medication has a narrow therapeutic index, meaning the effective dose is close to the toxic dose, so careful dosing and monitoring are essential[8]. Treatment is typically monitored through blood tests measuring thyroid stimulating hormone (TSH) levels, with the goal of maintaining TSH within a therapeutic range of 0.4-4.0 mIU/L[8]. Levothyroxine sodium should not be used for weight loss or obesity treatment, as doses beyond the range of daily hormonal requirements can produce serious or even life-threatening toxicity[5][1].

Brand names

SynthroidLevoxylLevo-TUnithroidTirosintTirosint-SolEuthyroxLevothroidErmeza

Other names

levothyroxine