Nhận Dạng Quốc Tế & Đặc Tính Hóa Học
Công thức hóa học
Dược Lực Học :
Binding of thyrotropin alfa to TSH receptors on normal thyroid epithelial cells or on well-differentiated thyroid cancer tissue stimulates iodine uptake and organification. Thyrogen is an exogenous source of human TSH that offers an additional diagnostic tool in the follow-up of patients with a history of well-differentiated thyroid cancer.
Cơ Chế Tác Dụng :
Thyrotropin alfa is a recombinant form of thyroid stimulating hormone used in performing certain tests in patients who have or have had thyroid cancer. It is also used along with a radioactive agent to destroy remaining thyroid tissue in certain patients who have had their thyroid gland removed because of thyroid cancer. It is a heterodimeric glycoprotein comprised of two non-covalently linked subunits, an alpha subunit of 92 amino acid residues containing two N-linked glycosylation sites and a beta subunit of 112 residues containing one N-linked glycosylation site. The alpha subunit is nearly identical to that of human chorionic gonadotropin (hCG), luteinizing hormone (LH), and follicle-stimulating hormone (FSH). The alpha subunit is thought to be the effector region responsible for stimulation of adenylate cyclase (involved the generation of cAMP). The beta subunit (TSHB) is unique to TSH, and therefore determines its receptor specificity. The amino acid sequence of thyrotropin alfa is identical to that of human pituitary thyroid stimulating hormone.
Thyrotropin Alfa binds to the thyrotropin receptors found on any residual thyroid cells or tissues. This stimulates radioactive iodine uptake for better radiodiagnostic imaging.
Dược Động Học :
▧ Absorption :
Time to peak: Median: 10 hours (range: 3-24 hours)
After a single intramuscular injection of 0.9 mg of thyrotropin alfa: Cmax= 116+38mU/L, Tmax=22+8.5 hours. AUC=5088+1728 mU·hr/L.
▧ Route of Elimination :
kidney and liver
▧ Half Life :
25 ± 10 hours
Độc Tính :
No difference in efficacy and toxicity between adult and geriatric patients. No studies in lactating women, pregnant women and pediatrics. Cautionary administration is advised.
Chỉ Định :
For detection of residueal or recurrent thyroid cancer
Liều Lượng & Cách Dùng :
Powder, for solution - Intramuscular
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