Table 1.

The approved indications and off-label uses of levothyroxine

Overt or subclinical hypothyroidism

ȃCongenital

ȃIodine deficiency

ȃThyroiditis: Hashimoto, subacute granulomatous, postpartum.

ȃSecondary: pituitary tumor and treatments used for this pathology (surgery, radiotherapy), Sheehan syndrome, empty sella syndrome, etc.

ȃIatrogenic: thyroidectomy, radioiodine therapy, antithyroid drugs, etc.

ȃNonantithyroid drug: iodinated contrast mediaa, lithium, tyrosine kinase inhibitors, interferons

Myxedema coma

Off-label uses

ȃSimple goiter

ȃFemale infertility with elevated thyroid antibodies

ȃCardiovascular diseases: chronic congestive heart failure, myocardial ischemia, coronary artery bypass

ȃNeurological disorders: Alzheimer's disease, multiple sclerosis, chorea

ȃOrgan transplantation

ȃProlonged critical illness

ȃHypercholesterolemia

ȃObesity

ȃUnexplained fatigue

ȃDepression

ȃCosmetic use (creams)b

Examples include iohexol, iopamidol, iopromide, ioversol, iobitridol, iomeprol, iodixanol, etc. Oil-soluble media increase the risk of contrast media-induced hypothyroidism compared with water-soluble ones.

Levothyroxine is added into some creams to accelerate the metabolism of epithelium and to reduce subcutaneous adipose tissues.