Primary hypothyroidism

Reduced circulating thyroid hormone levels due to thyroid gland dysfunction. Presents with fatigue, cold intolerance, dry skin, bradycardia, and weight gain.

ICD-10 E031 drug

Also known as: Hypothyroidism, Underactive thyroid

Drugs used for this condition

ALevothyroxine sodiumFirst line · Thyroid hormonesReplacement therapy in primary hypothyroidism – first-line and sole therapy per ATA 2014 and NICE. Starting dose in young adults is 1.6 mcg/kg/day. In elderly and patients with ischemic heart disease, start at 12.5–25 mcg and titrate slowly. TSH target is 0.4–4.0 mU/L, with an upper limit up to 6 mU/L acceptable in the elderly. T4+T3 combinations are not routinely recommended.

How to read tiers A–F

Evidence tiers belong to the drug-indication pair, not to the drug as a whole: the same substance can be A for one condition and F for another.

AStrong evidence – first or second line in international guidelines
BRecommended in selected cases
CStudy data contradict each other
DBenefit not proven, no documented harm
FDocumented harm, or risk without benefit