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

The synthetic hormonal agent, by its pharmacological and clinical properties, is similar to the endogenous oxytocin of the posterior lobe of the pituitary gland.Interacts with oxytocin-specific receptors of uterine myometrium, belonging to the superfamily G-proteins. The number of receptors and reaction to the action of oxytocin increases with the progression of pregnancy and reach a maximum at the end of it. Stimulates the labor of the uterus by increasing the permeability of cell membranes for Ca²⁺ and an increase in intracellular ion concentration, a subsequent decrease in the resting potential of the membrane and an increase in its excitability. Causes contractions, like normal spontaneous labor, temporarily worsening the blood supply of the uterus. With an increase in the amplitude and duration of muscle contractions, the uterine pharynx extends and smooths. In appropriate quantities it is able to strengthen the contractile capacity of the uterus from moderate in strength and frequency, characteristic of spontaneous motor activity, to the level of prolonged tetanic contractions. It causes a reduction in myoepithelial cells adjacent to the breast alveoli, improving the excretion of breast milk.

Influencing the smooth muscles of the vessels, causes vasodilation and increases blood flow in the kidneys, coronary vessels and vessels of the brain.Typically, blood pressure remains unchanged, however, with intravenous administration of large doses or a concentrated solution of oxytocin, blood pressure may temporarily decrease with the development of reflex tachycardia and a reflex increase in cardiac output. Following the initial decrease in blood pressure, there should be a prolonged, albeit small, increase.

Unlike vasopressin, oxytocin has a minimal antidiuretic effect, however, hyperhydration is possible when oxytocin is administered with large amounts of electrolyte-free liquids and / or when they are administered too quickly. Does not cause contraction of the muscles of the bladder and intestines.

Pharmacokinetics:

With intravenous administration, the effect of oxytocin on the uterus appears almost instantaneously and lasts for 1 hour. With intramuscular injection, the myotonic effect occurs in the first 3-7 minutes and lasts for 2-3 hours.

Like vasopressin oxytocin is distributed throughout the extracellular space. Small amounts of oxytocin appear to enter the fetal circulation. The half-life is 1-6 minutes, it is shorter in the late period of pregnancy and during lactation.Most of the drug is rapidly metabolized in the liver and kidneys. In the process of enzymatic hydrolysis, it is inactivated primarily by tissue oxytokinase (oxytokinase is also in the placenta and plasma). Only a small amount of oxytocin is excreted by the kidneys unchanged.

Indications:Oxytocin is intended for induction and stimulation of labor (primary and secondary weakness of labor, the need for early delivery in connection with gestosis, rhesus-conflict, intrauterine fetal death, premature pregnancy, premature amniotic fluid withdrawal, management of breech delivery).

For the prevention and treatment of hypotonic uterine bleeding after abortion (including during long periods of pregnancy), in the early postpartum period to accelerate the postpartum involution of the uterus; for contraction of the uterus in cesarean section (after removal of the afterbirth).

Contraindications:

Hypersensitivity; a narrow basin (anatomical and clinical), transverse and obliqueposition of the fetus, facial presentation of the fetus, premature birth, threatening rupture of the uterus,scars on the uterus (after a previous cesarean section, operations on the uterus), excessive uterine stretching, uterus after multiple births, partial placenta previa, uterine sepsis, invasive cervical carcinoma; hypertension of the uterus (not due to birth), fetal compression, arterial hypertension, chronic renal failure (CRF).

Pregnancy and lactation:

In the first trimester of pregnancy oxytocin apply only with spontaneous or induced abortion. Numerous data on the use of oxytocin, its chemical structure and pharmacological properties indicate that, if the recommendations for use are observed, the likelihood of oxytocin influence on increasing the frequency of fetal malformations is low.

In small amounts penetrates into breast milk.

When using the drug to stop uterine bleeding for breast-feeding, you can proceed only after the course of treatment with oxytocin.

Dosing and Administration:

Intravenous or intramuscular.

With the aim of induction and strengthening of labor activity oxytocin used exclusively intravenously, in a hospital,with appropriate medical supervision.

The simultaneous use of the drug intravenously and intramuscularly is contraindicated.

The dose is selected taking into account the individual sensitivity of the pregnant and fetus.

For induction and stimulation of labor Oxytocin is used exclusively as an intravenous drip infusion. Strict monitoring of the prescribed rate of infusion is mandatory. For the safe use of oxytocin during induction. and strengthening of labor, it is necessary to use an infusion pump or other similar device, as well as monitoring the strength of uterine contractions and cardiac activity of the fetus. In case of excessive strengthening of the contractile activity of the uterus, the infusion should be stopped immediately, as a result, the excess muscular activity of the uterus rapidly decreases.

1) Before proceeding with the introduction of the drug, you should start to enter the physiological - a solution that does not contain oxytocin.

2) To prepare a standard infusion of oxytocin in 1000 ml of non-hydrating fluid, dissolve 1 ml (5 ME) oxytocin and mix thoroughly by rotating the vial.In 1 ml of the infusion so prepared, 5 DM of oxytocin are contained. To accurately dispense the infusion solution, an infusion pump or other similar device should be used.

3) The rate of administration of the initial dose should not exceed 0.5-4 milliunits per minute (medmin) (corresponds to 2-16 cap / min, since 1 drop of infusion contains 0.25 MED oxytocin).

Every 20-40 minutes it can be increased by 1-2 mU / min until it is reached the desired degree of contractile activity of the uterus. When the desired frequency is reached uterine contractions, the corresponding spontaneous labor, and the opening of the pharynx of the uterus to 4-6 cm in the absence of signs of fetal distress can gradually reduce the infusion rate at a rate similar to its acceleration.

In later pregnancy, infusion with greater speed requires caution, only in rare cases it may take a speed exceeding 8-9 medmin. In the case of preterm delivery, a higher rate may be required, which in some cases may exceed 20 mdmin (80 cap / min).

1) It is necessary to control the fetal heart rate, the tone of the uterus at rest, the frequency, duration and force of its contractions.

2) In the case of uterine hyperactivity or fetal distress, oxytocin should be discontinued immediately and oxygen therapy provided to the mother. The condition of the mother and fetus must be checked again by a specialist doctor.

Prevention and treatment of hypotonic bleeding in the postpartum period:

1) Intravenous drip infusion: in 1000 ml of non-hydrating fluid dissolve 10-40 ME oxytocin; for the prevention of uterine atony usually requires 20-40 pm / min oxytocin.

2) Intramuscular injection: 5 IU / ml oxytocin after placenta separation.

Incomplete or failed abortion:

10 IU of oxytocin is added to 500 ml of saline or a mixture of 5% dextrose with saline. The rate of intravenous infusion is 20-40 drops / min.

Side effects:

At parturient women:

From the genitourinary system: with high doses or hypersensitivity - hypertension of the uterus, spasm, tetany, rupture of the uterus; increased bleeding in the postpartum period as a result of oxytocin induced thrombocytopenia, afibrinogenemii and gipoprotrombinemii, sometimes hemorrhages in the pelvic organs.With careful medical supervision of childbirth, the risk of bleeding in the postpartum period is reduced.

From the side of the cardiovascular system: when using large doses, arrhythmia; ventricular extrasystole; severe hypertension (in the case of vasopressor drugs); hypotension (with simultaneous use with anesthetic cyclopropane); reflex tachycardia; shock. At too fast introduction: a bradycardia, a subarachnoidal bleeding.

From the digestive system: nausea, vomiting.

From the side of water-electrolyte exchange: with prolonged intravenous administration (usually at 40-50 pm / min) with a large amount of fluid (antidiuretic effect of oxytocin), it is possible to develop severe hyperhydration, which occurs with seizures and coma. This condition can occur with a 24-hour, slow infusion of oxytocin. Rarely - lethal outcome.

Allergic reactions: anaphylaxis and other allergic reactions, with too rapid introduction of bronchospasm; rare - lethal outcome.

In a fetus or newborn:

As a result of the administration of oxytocin to the mother - within 5 minutes a low score on the Apgar scale, jaundice of newborns,at too fast introduction - decrease in a fibrinogen in a fetal blood, a hemorrhage in a retina of an eye; as a result of increased contractile activity of the uterus - sinus bradycardia, tachycardia, ventricular extrasystole and other arrhythmias, residual changes in the central nervous system, fetal death due to asphyxia due to increased contractile activity of the uterus.

Overdose:

Symptoms depend mainly on the degree of uterine hyperactivity, regardless of the presence of hypersensitivity to the drug. Hyperstimulation with hypertonic and tetanic contractions or with a basic tone ≥15-20 mm aq. Art. between two contractions leads to erratic labor, rupture of the body or cervix, vagina, postnatal bleeding, utero-placental insufficiency, fetal bradycardia, its hypoxia, hypercapnia, compression, birth trauma or death.

Hyperhydration with seizures as a result of the antidiuretic effect of oxytocin is a serious complication and develops with prolonged administration of large doses (40-50 ml / min).

Treatment of hyperhydration: elimination of oxytocin, restriction of fluid intake, use of diuretics to force diuresis, intravenous hypertonic saline, correction of electrolyte imbalance, arresting seizures with appropriate doses of barbiturates and providing professional care for the patient in a coma.

Interaction:

When oxytocin is administered 3-4 hours after using vasoconstrictors in combination with caudal anesthesia, severe arterial hypertension is possible.

With anesthesia with cyclopropane, halothane, cardiovascular action of oxytocin may change, with unforeseen development of arterial hypotension, sinus bradycardia, and atrioventricular rhythm in the parturient woman during anesthesia.

Special instructions:

Before inserting the fetal head into the pelvic inlet, apply oxytocin to stimulate childbirth can not. Before proceeding with the use of oxytocin, the expected beneficial effect of therapy should be compared with the possibility, albeit rare, of the development of hypertension and tetanus of the uterus. Each patient receiving oxytocin intravenously, should be in a hospital under the constant supervision of experienced specialists who are well acquainted with the drug and recognized as qualified in recognition of complications. It should be provided immediately, if necessary, the assistance of a specialist doctor. During the use of the drug should be constantly monitored uterine contractions, cardiac activity of the parturient woman and fetus, the arterial blood pressure of the parturient woman in order to avoid complications. If signs of hyperactivity in the uterus should immediately stop the introduction of oxytocin; as a result of this, uterine contractions caused by the drug, usually, soon subsided.

With adequate application oxytocin causes uterine contractions similar to spontaneous childbirth. Excessive stimulation of the uterus with improper application of the drug is dangerous for the woman in labor, and for the fetus. Even with adequate application of the drug and appropriate observation, hypertensive contractions of the uterus occur with increased sensitivity of the uterus to oxytocin.

It is necessary to consider the risk of development of afibrinogenemia and increased blood loss.There are known cases of maternity death as a result of hypersensitivity reactions, subarachnoid hemorrhage, uterine rupture, and fetal death for various reasons associated with parenteral administration of the drug for the induction of labor and stimulation in the first and second periods of labor.

As a result of the antidiuretic effect of oxytocin, the development of hyperhydration is possible, especially with the use of a continuous infusion of oxytocin and the use of fluid inside.

The drug can be diluted in solutions of sodium lactate, sodium chloride and glucose. The finished solution should be used within the first 8 hours after preparation. Compatibility studies were performed with infusions of 500 ml.

Effect on the ability to drive transp. cf. and fur:

Oxytocin does not affect the ability to drive a car and mechanisms that are associated with an increased risk of injury.

Form release / dosage:

Solution for infusion and intramuscular injection, 5 IU / ml.

Packaging:

1 ml of the drug in a vial of colorless glass (I hydrolytic class) with a point for fracture.

5 ampoules in contour plastic packaging.

On 1 contour plastic packing together with instructions for use in a cardboard bundle.

Storage conditions:

Store at a temperature of 2 to 15 ° C, in a place protected from light.

Keep out of the reach of children.

Shelf life:

3 years.

Do not use the drug after the expiration date.

Terms of leave from pharmacies:On prescription

Registration number:P N 013027/01

Date of registration:02.08.2011 / 15.02.2017

Expiration Date:Unlimited

The owner of the registration certificate:GEDEON RICHTER, OJSC GEDEON RICHTER, OJSC Hungary

Manufacturer: & nbsp

GEDEON RICHTER, Ltd. Hungary

Representation: & nbspGEDEON RICHTER OJSC GEDEON RICHTER OJSC Hungary

Information update date: & nbsp25.05.2017

Illustrated instructions

Instructions

Oxytocin Richter (Oxytocin-Richter)