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Các tên gọi khác (4 ) :
  • Pitocin
  • SID29217903
  • SID50111741
  • Syntocinon
Thuốc có tác dụng thúc đẻ, cầm máu sau đẻ và chống đẻ non
Thuốc Gốc
CAS: 50-56-6
ATC: H01BB01, H01BB02
ĐG : APP Pharmaceuticals , http://www.apppharma.com
CTHH: C43H66N12O12S2
PTK: 1007.1870
Synthetic 9 residue cyclic peptide. The hormone is prepared synthetically to avoid possible contamination with vasopressin (ADH) and other small polypeptides with biologic activity.
Nhận Dạng Quốc Tế & Đặc Tính Hóa Học
Công thức hóa học
Phân tử khối
Độ kỵ nước
Điểm đẳng điện tích
Dược Lực Học : Indirectly stimulates contraction of uterine smooth muscle by increasing the sodium permeability of uterine myofibrils. Increases contraction amplitude and frequency, which tends to decrease cervical activity, produce dilation and effacement of the cervix, and transiently impede uterine blood flow; contractions produced by oxytocin at term are similar to those occurring during spontaneous labor. High estrogen concentrations lower the threshold for uterine response to oxytocin. Uterine response increases with the duration of pregnancy and is greater in labor than when not in labor; only very large doses elicit contractions in early pregnancy. Contracts myoepithelial cells surrounding the alveoli of the breasts, forcing milk from the alveoli into the larger ducts and facilitating milk ejection. Minimal antidiuretic activity relative to vasopressin; water intoxication possible at high doses and/or excessive electrolyte-free fluid.
Cơ Chế Tác Dụng : Synthetic 9 residue cyclic peptide. The hormone is prepared synthetically to avoid possible contamination with vasopressin (ADH) and other small polypeptides with biologic activity. Uterine motility depends on the formation of the contractile protein actomyosin under the influence of the Ca2+-dependent phosphorylating enzyme myosin light-chain kinase. Oxytocin promotes contractions by increasing the intracellular Ca2+, which in turn activates myosin's light chain kinase.. Oxytocin has specific receptors in the muscle lining of the uterus and the receptor concentration increases greatly during pregnancy, reaching a maximum in early labor at term.
Dược Động Học :
▧ Absorption :
Uterine response after IV administration is immediate and subsides after 1 hour. Uterine contractions occur 3-5mins after IM administration and decreases within 2-3 hours. When 100-200milliunits is administered IV, contractions of the myoepithelial tissue surrounding the alveoli of the breasts occur within minutes and last for about 20 mins.
▧ Volume of Distribution :
Distributes throughout the extracellular fluid and crosses the placenta. It is probable that it also distributes into milk in small amounts.
▧ Protein binding :
▧ Metabolism :
Oxytocin is rapidly metabolized in the liver and also in the plasma by oxytocinases. It is also metabolized to a smaller degree by the mammary glands.
▧ Route of Elimination :
Biliary and renal (excreted unchanged in the urine)
▧ Half Life :
1-6 min, this is decreased in late pregnancy and during lactation.
Độc Tính : Oxytocin can produce a severe water intoxication due to its antidiuretic effect. Prolonged IV infusions of more 40milliunits/min are usually the cause. Severe water intoxication with convulsions, coma, and death can occur. Some neonatal seizures have also been reported. Consider potential for water intoxication, particularly when administered by IV infusion and patient is receiving oral fluids. Uterine effects: High doses or hypersensitivity to oxytocin may cause uterine hypertonicity, spasm, tetanic contraction, or rupture of the uterus. There have also been reported allergic and anaphylactic reactions to oxytocin but they were rarely fatal.
Chỉ Định : Used for labor induction, augmentation of labor, postpartum abbreviation of third stage of labor, postpartum control of uterine bleeding, termination of pregnancy and for the evaluation of fetal respiratory capability. Oxytocin cannot be used for elective induction of labor, there must be a clear medical requirement.
Tương Tác Thuốc :
  • Carboprost Tromethamine Avoid combination due to enhanced oxytocic effects.
  • Dinoprostone Therapy modification should be considered because of enhanced oxytocic effects
  • Epinephrine Possible marked increase of arterial pressure
  • Mifepristone Consider therapy modification because of potential enhanced effect of Q-Tc prolongation
  • Misoprostol Avoid combination. Manufacturer advises not to administer concomitantly due to enhanced adverse effects of oxytocin, especially when given within 4 hours of oxytocin initiation.
  • Phenylephrine Possible marked increase of arterial pressure
Liều Lượng & Cách Dùng : Solution - Intramuscular
Solution - Intravenous
Dữ Kiện Thương Mại
Giá thị trường
Nhà Sản Xuất
  • Công ty : BAM Biotech
    Sản phẩm biệt dược : Oxytocin
  • Công ty : Parke-Davis
    Sản phẩm biệt dược : Pitocin
  • Công ty : Sandoz
    Sản phẩm biệt dược : Syntocinon
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