Oxytocin

Pharmacological properties

Synthetic oxytocin has the same biological properties as natural hormone. the drug causes severe contractions in the muscles of the uterus, especially in the pregnant woman, due to the influence of the myometrium cells on the membranes. under the influence of oxytocin, the permeability of membranes for potassium ions increases, their potential decreases and excitability increases. oxytocin stimulates the secretion of milk, increases the production of lactogenic hormone of the anterior pituitary gland - prolactin. in addition, the drug contributes to the rapid release of milk from the mammary gland as a result of action on its contractile elements. oxytocin has a weak diuretic effect and does not significantly affect hell. a change in the secretion of oxytocin leads to a pathological course of childbirth and a violation of the activity of the mammary gland during lactation.

The plasma half-life is 3-5 minutes. This hormone is inactivated by the enzyme oxytocinase contained in the blood of pregnant women (the enzyme disappears from the body 10-14 days after birth), as well as by specific enzymes located in the kidneys, uterus, and retro-placental blood plasma. Due to the absence of proteins in the preparation, its introduction is safe from the point of view of the possibility of the development of anaphylactic shock and pyrogenic action.

Indications

For the induction of labor and their stimulation with weak labor (the drug is most effective for premature discharge of water). It is also prescribed for the prevention and treatment of hypotonic uterine bleeding in the early postpartum period (including to accelerate uterine involution), for the artificial induction of labor in pregnancy complications, to enhance the contractile activity of the uterus during cesarean section, and to enhance lactation.

Application

Introduced in / in, in / m, as well as in the cervix or wall of the uterus.

To stimulate labor, 0.5–2 IU of oxytocin is injected intramuscularly; if necessary, the injections are repeated every 30-60 minutes. In case of weak labor, a prolonged (throughout the entire labor process) iv drip of oxytocin at a dose of 5 IU is recommended. Before use, 1 ml (5 IU) of the drug is diluted in 500 ml of 5% glucose solution.

The introduction begins with a speed of 5-8 drops / min, gradually increasing it (every 5-10 minutes by 5 drops, but not more than 40 drops / min) until the establishment of vigorous labor. After its establishment, the amount of solution that is introduced can be reduced to a minimum support. Simultaneous iv administration of the drug in a dose of 0.2 ml (1 IU) in 20 ml of 40% glucose solution is allowed only with the full opening of the cervix and the conditions for rapid natural delivery.

To stimulate contractions, usually 0.25–1 IU of oxytocin is administered IM.

For the prevention of hypotonic uterine bleeding, oxytocin is administered IM 3–5 IU 2-3 times a day every day for 2-3 days; for bleeding, 5–8 IU is administered 2-3 times a day for 3 days. Depending on the clinical situation, you can also enter in / in or in the cervix. If necessary, both for prophylaxis and for treatment, the administration of the drug can be repeated after a 4–5-day break.

In cesarean section (after fetal extraction), oxytocin is injected iv or into the uterus muscle in a dose of 3-5 IU to prevent bleeding.

To enhance lactation, oxytocin is administered i / m at 1–2.5 IU 30–40 min before feeding for 3–5 days.

Contraindications

The use of oxytocin for the stimulation of labor is contraindicated if the size of the mother’s pelvis does not match the fetal head, the lateral and oblique position of the fetus, the presence of scars on the uterus after previous cesarean section or other operations on the uterus, with suspected premature detachment of the placenta, with intrauterine hypoxia of the fetus, placenta previa, menacing uterine rupture.

Side effects

When using oxytocin, nausea, vomiting, extrasystole, bradycardia, arrhythmia of the fetal cardiac activity are possible.allergic reactions in the form of bronchospasm are also possible (in patients with BA).

special instructions

Apply only under the supervision of a doctor, be sure to consider individual sensitivity to the drug. in some cases, after administration of oxytocin at a dose of 1 unit, sharp contractions can develop, as a result of which intrauterine hypoxia of the fetus occurs, in other cases, the total dose of the drug can be 4–5 IU. sometimes, oxytocin is prescribed in combination with prostaglandins to stimulate labor. with intravenous administration of the drug during childbirth from the beginning of drip administration, it is recommended to use antispasmodic and analgesic agents (promedol, aprofen, etc.). iv administration of the drug causes a rapid increase in contractions (after 1 / 2–1 min) - sluggish contractions become more intense, and in the absence of contractions they usually appear. v / m introduction has a less dramatic effect. oxytocin must be used under the control of contractile activity of the uterus, the condition of the fetus, hell and the general condition of the woman.

Overdose

It manifests itself as symptoms of uterine hyperstimulation (tetanic contractions of the uterine muscles), preeclampsia, urinary retention, increased hell, as well as excessively active labor, which can cause acute fetal hypoxia, premature detachment of a normally located placenta, and uterine rupture. if there are signs of complications, it is necessary to stop the administration of the drug and conduct symptomatic treatment (reduce the administration of fluid, use forced diuresis to remove oxytocin).

Storage conditions

In a dark place at a temperature of 8–20 ° C. do not freeze!