Oxytocin

General characteristics. Structure:

Active ingredient: oxytocin synthetic 5 ME.

Excipients: water for injections.

Pharmacological properties:

Pharmacodynamics. Oxytocin – a synthetic polypeptide analog of hormone of a back share of a hypophysis – stimulates reduction of smooth muscles of a uterus (especially pregnant) and myoepithelial cells of a mammary gland. Under the influence of oxytocin permeability for potassium ions increases, potential goes down and excitability of membranes increases. With reduction of membrane potential the frequency, intensity and duration of reductions increases. Oxytocin stimulates milk secretion, strengthening development of a lactogenic anterior pituitary hormone (prolactin).

Oxytocin renders weak antidiuretic effect and in therapeutic doses significantly does not influence arterial pressure.

The effect occurs in 1-2 min. at hypodermic and intramuscular introduction, 20-30 min. last; at intravenous administration – in 0,5 - 1 min.

Pharmacokinetics. T ½-1-6 min. (decreases on late durations of gestation and in the period of a lactation). Communication with proteins of plasma low (30%).

It is metabolized in a liver and kidneys. During pregnancy in plasma, target organs, a placenta the maintenance of the oxytocinase inactivating endogenous and exogenous oxytocin increases. Removal generally kidneys in an invariable look.

Indications to use:

For excitement and stimulation of patrimonial activity; for prevention and treatment of hypotonic uterine bleedings in an early puerperal period and for acceleration of puerperal involution of a uterus: for strengthening of sokratitelny ability of a uterus at Cesarean section (after a removing the fetus).

Route of administration and doses:

Oxytocin is entered intravenously or intramusculary. For initiation of childbirth enter intramusculary 0,5-2,0 ME oxytocins. If necessary repeat injections each 30-60 minutes.

For intravenous drop administration part 1 ml of oxytocin (5 ME) in 500 ml of 5% of solution of glucose. Introduction there begin with 5-8 drops a minute, with the subsequent increase in speed depending on the nature of patrimonial activity, but no more than 40 drops a minute. For prevention of hypotonic uterine bleedings oxytocin is entered intramusculary on 3-5 ME 2-3 times a day daily within 2-3 days, and for treatment of hypotonic uterine bleedings entered 5-8 ME 2-3 times a day within 3 days.

At operation of Cesarean section (after removal of an afterbirth) oxytocin is entered into a uterus wall in a dose 3-5 ME.

Features of use:

Oxytocin is applied only under observation of the doctor in the conditions of a hospital under control of sokratitelny activity of a uterus, a condition of a fruit, arterial pressure and the general condition of the woman.

Side effects:

At use of oxytocin are possible: nausea, vomiting, arrhythmia and bradycardia (at mother and a fruit), allergic reactions, a bronchospasm, an ischuria and increase in arterial pressure, shock, subarachnoidal bleeding, neonatal jaundice, decrease in fibrinogen at a fruit, a water delay, and also excessively vigorous patrimonial activity that can cause a fruit hypoxia, premature amotio of normally located placenta, a hysterorrhesis. At manifestation of symptoms of these complications it is necessary to stop administration of drug immediately.

Interaction with other medicines:

With care apply oxytocin in a combination with sympathomimetics (potentsiirut pressor action of sympathomimetics). The halothane and cyclopropane strengthen risk of development of arterial hypotension. In combination with MAO inhibitors the risk of increase in arterial pressure increases.

Contraindications:

Use of oxytocin is contraindicated at hypersensitivity to drug, the increased arterial pressure, a renal failure, predisposition to a hysterorrhesis, discrepancy of the sizes of a basin of mother and the sizes of a fruit, the cross and slanting provision of a fruit, existence of hems on a uterus after the postponed kesarevy section or other uterus operations, suspicion on premature placental detachment, a pre-natal hypoxia of a fruit, at placental presentation.

Overdose:

Symptoms of hyper stimulation of a uterus that can lead to a hyper tone and tetanic reductions of a uterus which, in turn, can lead to a hysterorrhesis, puerperal bleeding, various changes from cordial activity of a fruit, a fruit death hypoxia: fruit prelum, fruit asphyxia, fruit bradycardia, uterine placental hypoperfusion, hypercapnia, birth trauma of a fruit, water intoxication, spasms.

Treatment: it is necessary to stop immediately introduction of oxytocin, to reduce administration of liquid, to force a diuresis, to administer the symptomatic drugs, hypertonic saline solutions (for the purpose of normalization of electrolytic balance), barbiturates (with care). Behind a placenta careful observation is necessary.

Storage conditions:

To store in the place protected from light at a temperature from 8 to 20 °C. To store in the place, unavailable to children.

Issue conditions:

According to the recipe

Packaging:

On 1 ml of the solution containing 5 ME oxytocins in ampoules from neutral glass.

5 or 10 ampoules with the application instruction, the ampoule scarificator are located in a pack from a cardboard with a corrugated insert.