Medication Description: Thyroid (Thyreoidinum)
A hormonal drug derived from dried, defatted thyroid glands of slaughter cattle.
Synonyms: Thyranon, Thyroid, Thyrotan.
Yellow-gray powder with a faint odor characteristic of dried animal tissue. Insoluble in water, alcohol and other solvents.
Possesses the biological activity of the thyroid hormone.
Standardized for the content of organically bound iodine (from 0.17 to 023%).
The action of thyroidin is associated with the presence of two hormones in it: thyroxine and triiodothyronine (in the body both are levorotatory isomers).
Chemically, thyroxin differs from triiodothyronine in the presence of one additional iodine atom in the molecule.
Both hormones have a similar multifaceted effect on the body, increase tissue oxygen demand, increase energy processes, stimulate tissue growth and differentiation, affect the functional state of the nervous and cardiovascular systems, liver, kidneys and other organs and systems, increase glucose absorption and its recycling. The effect of thyroid hormones may vary with the dose. Thus, small doses of thyroxin have an anabolic effect, while large doses lead to increased protein breakdown. In large doses, thyroid hormones inhibit the thyroid-stimulating activity of the pituitary gland.
Triiodothyronine is 3–5 times more effective than thyroxin, and acts faster because it binds less to blood proteins, is transported mostly free in the blood and penetrates cell membranes faster. The latent period of action of triiodothyronine is 4–8 hours, and that of thyroxin 24 is 48 hours.
Currently, triiodothyronine is obtained synthetically; it is used as an independent therapeutic drug (see Triiodothyronine hydrochloride).
Thyroidin and triiodothyronine is prescribed (in relatively small doses) with insufficient thyroid function and at higher doses (not causing hyperthyroidism, but sufficient to suppress thyrotropic activity) - with excessive thyroid stimulating function of the pituitary gland. The main indications for their use are primary hypothyroidism and myxedema, cretinism, cerebral-pituitary diseases occurring with hypothyroidism, obesity with signs of hypothyroidism, endemic and sporadic goiter, and thyroid cancer.
Thyroidine has a cholesterol-lowering effect in patients with atherosclerosis. The mechanism of action seems to be associated with the stimulation of cholesterol catabolism. The clinical use of thyroidin for this purpose, however, is limited due to the possible gain in patients with strokes.
Assign thyroidin inside. Doses should be carefully individualized, taking into account the age of the patient, the nature and course of the disease. Is ingested in the first half of the day after meals.