Oxytocin - instructions for use, dose, side effects, contraindications

Oxytocin is a synthetic polypeptide analogue of the hormone of the posterior lobe of the pituitary gland. Has a stimulating effect on the smooth muscles of the uterus, increases the contractile activity and tone of the myometrium.Promotes the reduction of myoepithelial cells surrounding the alveoli of the mammary glands, which leads to the release of milk. It has weak antidiuretic and pressor activity. With rapid intravenous injection oxytocin has a relaxing effect on the smooth muscles of the vessels, which leads to temporary arterial hypotension and reflex tachycardia. Does not cause contraction of the muscles of the bladder and intestines.

Pharmacokinetics:

Ingestion oxytocin it breaks down in the gastrointestinal tract, in connection with which it is administered parenterally. The connection with proteins is low - no more than 30%. Metabolized by the liver, excreted by the kidneys. The half-life on average is 5 minutes.

Under the influence of oxytocin, the permeability of cell membranes for ions Ca²⁺, the resting potential decreases and their excitability increases (a decrease in the membrane potential leads to an increase in the frequency, intensity, and duration of contractions). The effect occurs in 1-2 minutes with subcutaneous and intramuscular injection, lasts for 20-30 minutes; at intravenous introduction - through 0,5-1 minutes.

Indications:

- Induction and stimulation of labor;

- prevention and treatment of hypotonic uterine bleeding in the early postpartum period (with caesarean section the drug is injected into the uterus muscle) and after abortion;

- subinvolution of the postpartum uterus.

Contraindications:

- HCorrespondence of fetal and pelvic maternity size (clinical or anatomical narrow pelvis);

- transverse or oblique position of the fetus;

- facial presentation of the fetus;

- excessive stretching of the uterus, threat of rupture of the uterus;

- hypertension of the uterus (which did not occur during labor);

- presence of scars on the uterus after a previous cesarean section or other operations on the uterus;

- placenta previa;

- suspicion of premature placental abruption;

- premature delivery;

- intrauterine fetal hypoxia;

- compression of the fetus;

- multiple births in anamnesis;

- arterial hypertension;

- kidney failure;

- uterine septicemia;

- invasive cervical carcinoma;

- hypersensitivity to oxytocin.

Dosing and Administration:

Oxytocin is administered intravenously or intramuscularly, intravenously - slowly.

For induction: intramuscularly 0.5-2.0 ME oxytocin; if necessary, repeat the injection every 30-60 minutes.With intravenous drip introduction, dilute 1 ml of synthetic oxytocin (5 ME) in 500 ml of a 5% solution of glucose. Introduction begins with 5-8 drops per minute, followed by an increase in speed, depending on the nature of labor, but not more than 40 drops per minute. During the infusion, constant monitoring of uterine activity and fetal heart rate is necessary.

For the prevention of hypotonic uterine bleeding oxytocin administered intramuscularly for 3-5 ME 2-3 times daily for 2-3 days, and for the treatment of hypotonic uterine bleeding, 5-8 ME 2-3 times a day for 3 days.

In cesarean section (after removing the afterburn) oxytocin injected into the wall of the uterus at a dose of 3-5 ME.

Side effects:

Possible: nausea, vomiting, arrhythmia and bradycardia (in the mother and fetus), allergic reactions, bronchospasm, urinary retention, increase / decrease in blood pressure (BP), shock, subarachnoid hemorrhage, excessively active labor, premature placental abruption, postpartum bleeding, rupture of the uterus, compression and acute hypoxia of the fetus, birth injuries of the fetus, neonatal jaundice, fetal hypofibrinogenemia.

If such symptoms appear, stop the injection immediately.

Overdose:Hyperstimulation of the uterus, which can lead to hypertonia and tetanic contractions of the uterus, which in turn can lead to rupture of the uterus, postpartum hemorrhage, various changes in cardiac fetal activity, hypoxia and fetal death. With long-term use of oxytocin in large doses by infusion (40-50 ml / min), symptoms associated with the antidiuretic effect of oxytocin may appear.

When an overdose should immediately stop the introduction of oxytocin, force diuresis, enter symptomatic drugs and hypertensive saline solutions (in order to normalize the electrolyte balance).

Interaction:

Use with caution oxytocin in combination with sympathomimetics (potentiates pressor action of sympathomimetics).

In combination with MAO inhibitors, the risk of increasing blood pressure increases.

Halothane and cyclopropane increase the risk of developing arterial hypotension.

Special instructions:

Apply only under the supervision of a doctor in a hospital environment under the control of the contractile activity of the uterus, fetal condition, blood pressure and the general condition of the woman.

Form release / dosage:

Solution for injection, 5 IU / ml.

Packaging:

1 ml of the drug into neutral glass ampoules with a notch and a colored break point.

10 ampoules are placed in a contour mesh package made of a polyvinyl chloride film.

1 circuit cell pack together with the instruction for use is placed in a cardboard box.

Storage conditions:

Store in a dark place at a temperature of 8 to 20 ° C.

Keep out of the reach of children.

Shelf life:

2 years.

Do not use after expiry date.

Terms of leave from pharmacies:On prescription

Registration number:LSR-001494/08

Date of registration:14.03.2008 / 17.03.2015

Expiration Date:Unlimited

The owner of the registration certificate: Mapichem AG Mapichem AG Switzerland

Manufacturer: & nbsp

SHANDONG SHENGLU PHARMACEUTICAL, Co.Ltd China

Representation: & nbspMapichem AGMapichem AG

Information update date: & nbsp25.05.2017

Illustrated instructions

Instructions

Oxytocin (Oxytocinum)