Also Known As: Cytomel, Tertroxin, Liothyronine
Liothyronine sodium is the L-isomer of triiodothyronine (T3), a form of thyroid hormone used to treat hypothyroidism and myxedema coma. It is marketed under the brand name Cytomel (or Tertroxin in Australia).
Liothyronine is the most potent form of thyroid hormone. As such, it acts on the body to increase the basal metabolic rate, effect protein synthesis and increase the body's sensitivity to catecholamines (such as adrenaline) by permissiveness. The thyroid hormones are essential to proper development and differentiation of all cells of the human body. These hormones also regulate protein, fat, and carbohydrate metabolism, affecting how human cells use energetic compounds.
In comparison to levothyroxine (T4), liothyronine has a faster onset of action as well as a shorter biological half-life, which may be due to less plasma protein binding to thyroxine-binding globulin and transthyretin.