OXYTOCIN

General characteristics. Structure:

Active ingredient: 1 ml of solution contains 5 ME oxytocins;

excipients: chlorbutanol гемигидрат, water for injections.

Main physical and chemical properties: transparent, colourless liquid with a specific smell.

Pharmacological properties:

Synthetic oxytocin has all biological properties inherent in the natural hormone emitted by a back share of a hypophysis.

Pharmacodynamics. Being peptide hormone (octapeptide) of a back share of a hypophysis, consists of an octapeptide cycle and a side chain from the remains of three amino acids (proline, a leucine, glycine). Oxytocin belongs to the means stimulating uterus muscles. Causes especially strong reductions of muscles of a uterus in pregnant women that is caused by its influence on membranes of cells of a myometrium. Use of oxytocin increases permeability of a membrane for potassium ions, reduces its potential and increases excitability. Oxytocin stimulates milk secretion, strengthening production of prolactin – a lactogenic anterior pituitary hormone. Besides, activates release of milk from a mammary gland owing to impact on its reducible elements. Oxytocin has weak antidiuretic effect and significantly does not influence the level of arterial pressure.

Pharmacokinetics. Oxytocin in digestive tract collapses under the influence of enzymes (pepsin, trypsin) in this connection it is applied parenterally. Does not contact proteins of a blood plasma, it is metabolized by a liver, removed by kidneys. The elimination half-life makes 5 minutes.

Indications to use:

Induction of childbirth, stimulation of patrimonial activity at primary and secondary patrimonial weakness, and also with care in the first and in the second the periods of childbirth. Prevention and treatment of placental bleedings and atonichny uterine bleedings (in case of carrying out operation of kesarevy section Oxytocin is entered directly into a uterus muscle). Insufficient involution of a uterus in a puerperal period (for control of subinvolution and bleeding). Incomplete or septic abortion. At gynecologic bleedings (after establishment of the histologic diagnosis).

Route of administration and doses:

The drug is administered intravenously, intramusculary, subcutaneously, and also in a neck or a wall of a uterus.

To induction or stimulation of patrimonial activity oxytocin is applied only in the form of intravenous drop infusion. Observance of the specified speed of infusion is obligatory. Safe use of oxytocin requires use of an infusional pomp or other similar adaptation, and also carrying out monitoring of uterine reductions and cordial activity of a fruit. In case of excessive strengthening of a sokratitelny deyalnost of a uterus it is necessary to stop at once infusion, as a result the excessive uterine uterine activity will quickly decrease.

For preparation of standard infusion of oxytocin in 500 ml of solvent (0,9% solution of sodium of chloride or 5% glucose solution) it is necessary to dissolve 1 ml (5 ME) of oxytocin and to mix. Rate of administering of an initial dose should not exceed 5-8 drops a minute. Each 20-40 minutes it can be increased by 5 drops, but not Bol, than before achievement of 40 drops in a minute, desirable degree of a sokratitelny deyalnost of a uterus will not be reached yet. At achievement of extent of uterine reductions, the corresponding normal patrimonial deyalnost, disclosure of a pharynx of a uterus on 4-6 cm, in the absence of signs of a fetalis distress it is possible to reduce gradually infusion speed at speed, to its similar acceleration. In the terminal period of pregnancy oxytocin can be entered quicker, however at the same time it is necessary to be careful as the infusion speed reaching 40 drops a minute only occasionally can be necessary. It is necessary to control heartbeat of a fruit, a uterus tone at rest, the frequency, duration and force of its reductions. In case of excessive uterine reductions or a distress of a fruit it is necessary to stop immediately introduction of oxytocin and to provide to the woman in labor oxygen therapy, at the same time the woman in labor and a fruit have to be under observation of the specialist doctor.

For a stop of uterine bleeding in a puerperal period:

1) Intravenous drop infusion: in 1000 ml (0,9% solution of sodium of chloride, 5% glucose solution) to dissolve 10-40 ME oxytocins.

2) Intramusculary: 1 ml (5 ME) of oxytocin after department of a placenta.

For prevention of atonichny uterine bleedings:

Oxytocin is entered intramusculary on 3-5 ME 2-3 times a day daily on an extent of 2-3 days.

As adjuvant therapy at incomplete abortion:

10 ME oxytocins in 500 ml of 0,9% of solution of sodium of chloride or mix of 5% of a dextrose from 0,9% chloride sodium solution. Speed of intravenous infusion – 20-40 drops a minute.

At Cesarean section – oxytocin is entered into a uterus muscle in a dose 5 ME.

At gynecologic indications – subcutaneously or intramusculary in a dose 5-10 ME.

Features of use:

Drug use contraindicated in the presence in the anamnesis of hypersensitivity to oxytocin.

Except for special cases, use of oxytocin is not recommended at premature births; at considerable extent of narrowing of a basin; earlier undergone uterus or neck of uterus operation, including after kesarevy section; excessive increase in a tone of a uterus; polycarpous pregnancy; invasive stages of a carcinoma of a neck of uterus. By the time of formation of a head or a basin of a fruit in an entrance of a basin it is impossible to apply oxytocin to induction of childbirth. Identification of the so-called special cases caused by connections of various factors is a task of the doctor. Before starting use of oxytocin, it is necessary to compare the expected positive effects of therapy with risks (though it is rare, but the hyper tone and a tetany of a uterus are possible).

For the purpose of induction of childbirth and strengthening of a sokratitelny deyalnost of a uterus oxytocin is applied exclusively intravenously, in a hospital, and under medical observation. Each patient who receives infusion of oxytocin has to be under constant observation of the doctor well familiar with drug and its side effects. The specialist doctor who had special training has to be on a case of development of side effects nearby.

To avoid complications, it is necessary to control constantly reductions of a uterus, cordial activity of the woman in labor and a fruit, arterial pressure of the woman in labor. At the first signs of a hyperactivity of a uterus it is necessary to stop introduction of oxytocin immediately; as a result of it the uterine reductions caused by drug, as a rule, soon disappear.

At adequate use oxytocin causes uterine reductions, similar to normal childbirth. Excessive stimulation which arises at the wrong use of drug is dangerous both to the woman in labor, and to a fruit.

It must be kept in mind that in hypersensitivity cases to drug hypertensive reductions are possible also at adequate use of drug. It is necessary to consider a possibility of strengthening of bleeding and development of an afibrinogenemiya.

Antidiuretic effect of drug favors to a water delay in an organism. On a possibility of an overhydratation it is necessary to pay special attention at use of continuous infusion of oxytocin and reception of liquid inside.

At parenteral administration drug is used either only intravenously, or only intramusculary.

Cases of death of women in labor as a result of hypersensitivity reactions, subarachnoidal hemorrhage, a hysterorrhesis, and also fruit death cases are known for various reasons at parenteral use of drug for the purpose of induction of childbirth and stimulation of uterine reductions.

Side effects:

At women in labor:

From a reproductive system: high doses or hypersensitivity to drug can cause arterial hypertension, spasms, a tetany and a hysterorrhesis; strengthening of bleeding in a puerperal period in a consequence of thrombocytopenia, an afibrinogenemiya and prothrombinopenia. The hematoma of a small pelvis is sometimes possible. It is possible to reach decrease in risk of bleeding in a puerperal period, exercising systematic control of the course of childbirth.

From cardiovascular system: use of high doses of oxytocin can cause arrhythmia, premature ventrikulyarny reductions, arterial hypertension after arterial hypotension, reflex tachycardia, bradycardia.

From the alimentary system: nausea, vomiting.

From water and electrolytic exchange: thanks to antidiuretic action of oxytocin at its bystry intravenous administration (more than 40 thaws/min.) along with a large amount of liquid the heavy overhydratation is possible. A condition of a heavy overhydratation with sudorga and a coma can develop also at slow, more than

24-hour infusional introduction of oxytocin.

From immune system: the anafilaktichesaky reactions connected with dispny, hypotension or shock; anaphylaxis and other allergic reactions; occasionally – a lethal outcome.

From a nervous system: headache.

From skin: enanthesis.

At a fruit or newborn: the low number of points on a scale Apgar when determining in 5 min. after the birth, jaundice of newborns, an eye retinal apoplexy at newborns.

Sinus bradycardia, tachycardia, premature ventrikulyarny reductions and other arrhythmias, residual injuries of the central nervous system and brain, fruit death because of asphyxia, as a result – strengthening of a kontraktilny uterine activity.

Interaction with other medicines:

At introduction of oxytocin in 3-4 h after simultaneous use of vasoconstrictors and against the background of caudal anesthesia heavy arterial hypertension is possible.

Anesthesia using cyclopropane can change cardiovascular effect of oxytocin – arterial hypotension is possible.

The case when simultaneous use of oxytocin and cyclopropane caused sinus bradycardia and an atrio-ventricular rhythm in the patient is known.

Prostaglandins can potentsiirovat ulcerogenic effect of oxytocin.

Contraindications:

Hypersensitivity to oxytocin; discrepancy of the sizes of a fruit and woman in labor basin, narrow basin (heavy extent of narrowing); the adverse provision of a fruit (slanting and cross) disturbing a spontaneous razrozhdeniye; the emergency situations caused by a condition of the woman in labor or a fruit which demand surgical intervention; a condition of a distress of a fruit long before terminal durations of gestation; uterus hyper tone; existence of contraindications for vaginal childbirth (for example, presentation or a prolapse of the umbilical cord, the central placental presentation and regional placental presentation).

In cases of a heavy toxaemia or a weak sokratitelny patrimonial uterine activity prolonged use of oxytocin is contraindicated.

Overdose:

Symptoms of overdose depend, mainly, from degree of sensitivity of a uterus to oxytocin and are not connected with existence of hypersensitivity to active component of drug. Hyper stimulation can lead to strong (hypertensive) and long (tetanic) reductions, or to rapid childbirth with a characteristic basic tone in 15-20 mm водн. the Art. also more which are measured between two reductions and also can cause a rupture of a body or neck of uterus, vagina, bleeding in a puerperal period, utero-placental hypoperfusion, delay of a cordial deyalnost of a fruit, a hypoxia, a hypercapnia and death of a fruit.

Prolonged use of drug in high doses (40-50 ml/min.) can be followed by heavy side effect – an overhydratation that is caused by antidiuretic effect of oxytocin.

Treatment consists in the termination of infusion of oxytocin, liquid reception restriction, use of diuretics, intravenous administration of hypertonic saline solution, correction of electrolytic balance, stopping of spasms with barbiturates and ensuring professional care of the patient who is in a coma.

Storage conditions:

To store in the place protected from light at a temperature from 8 °C to 15 °C.

Issue conditions:

According to the recipe

Packaging:

On 1 ml in ampoules No. 10.