Drugs_affecting_myometrium_ pharmacology.pptx

Drugs affecting myometrium

1. DRUGS AFFECTING MIOMETRIUM 1

2. Anatomical and physiological features of the structure of the uterus The uterus is a hollow smooth muscle organ capable of tonic and rhythmic (phase) contractions. Their occurrence is regulated by the nervous and endocrine systems . 2

3. Anatomical and physiological features of the structure of the uterus Estrogens activate uterine contractions, ↑ number of receptors for oxytocin, ↑ α- adrenergic receptors, ↓ activity of β- adrenoreceptors . Estrogens increase the synthesis of prostaglandins. 3

4. Anatomical and physiological features of the structure of the uterus Gestagens formation of intermuscular connections in myometrium , ↓ number of receptors for estradiol , oxytocin , ↓ activity of α- adrenoceptors and ↑activity of β- adrenoceptors, synthesis of prostaglandins . The agents affecting the contractility and tone of the uterus are subdivided into the following groups. 4

5. Classification I  Drugs predominantly affecting the contractile activity of myometrium Agents increasing the contractile activity of the myometrium (myometrial stimulants ) Hormones and drugs of the posterior lobe of the pituitary Oxytocin Pituitrinum Prostaglandin drugs Dinoprost (prostaglandin F 2 α ) Dinoprostone (prostaglandin E 2 ) 5

6. Classification Agents decreasing the contractile activity of the myometrium ( tocolytic drugs; myometrial relaxants)   Predominantly stimulating  β 2 - adrenoceptors Fenoterol Salbutamol Hexoprenaline ( ginipral )   Drugs used for general anesthesia Sodium hydroxybutyrate Other agents Magnesium sulphate 6

7. Classification II  Drugs predominantly increasing the tone of the myometrium  Agents of plant origin (alkaloids and ergot preparations) Ergometrine Ergotamine Ergot extract Ergotalum Synthetic drugs Cotarninum 7

8. Classification III  Drugs decreasing the tone of the cervix Atropine Dinoprost Dinoprostone 8

9. I Drugs predominantly affecting the contractile activity of myometrium Agents increasing the contractile activity of the myometrium (myometrial stimulants) Hormones and drugs of the posterior lobe of the pituitary Oxytocin Under the influence of oxytocin, the permeability of cell membranes to calcium ions Ca2+ increases, 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). 9

10. I Drugs predominantly affecting the contractile activity of myometrium Agents increasing the contractile activity of the myometrium (myometrial stimulants) Hormones and drugs of the posterior lobe of the pituitary Oxytocin 1 – causes uterine contraction during childbirth. 2 – facilitates the excretion of milk. Administration of high doses of oxytocin causes tonic contractions of the myometrium . Indications for use: stimulation of labor activity . In the postpartum period: with delayed placental discharge, atonic bleeding, slowing of uterine involution, to stimulate the separation of milk.

11. I Drugs predominantly affecting the contractile activity of myometrium Agents increasing the contractile activity of the myometrium (myometrial stimulants) Hormones and drugs of the posterior lobe of the pituitary Oxytocin Side effects: fluid retention, phlebitis, blood pressure. The child has: ↑ bilirubin in the blood plasma, hemorrhages in the retina . Contraindications: discrepancy between the size of the pelvis and the fetus, oblique and transverse position of the fetus, the presence of damage to the uterine wall, threatening rupture of the uterus. 11

12. I Drugs predominantly affecting the contractile activity of myometrium Agents increasing the contractile activity of the myometrium (myometrial stimulants) Hormones and drugs of the posterior lobe of the pituitary Oxytocin Ways of introduction : injected intravenously, theeffect develops after 0.5-1 min. Does not bind to plasma proteins blood . With intravenous administration, the effect occurs after 3-7 minutes and lasts 30min - 3 hours. Doses are selected individually. 12

13. I Drugs predominantly affecting the contractile activity of myometrium Agents increasing the contractile activity of the myometrium (myometrial stimulants) Prostaglandin drugs Dinoprost (prostaglandin F 2 α ) Dinoprostone (prostaglandin E 2 ) The main effects are: ↑ myometrial tone , " maturation" of the cervix; ↓ the number of β - adrenoreceptors and ↓ sensitivity to β - adrenomimetics . They have their effect on both a pregnant or non-pregnant uterus. 13

14.   Drugs predominantly affecting the contractile activity of myometrium Agents increasing the contractile activity of the myometrium (myometrial stimulants) Prostaglandin drugs Indications for use: stimulation of labor activity, opening of the uterine pharynx, termination of pregnancy at any time . Pharmacokinetics : administered intravenously, extra- intraamniotically , intravaginally , transbuccally . With local administration , they are more effective and cause fewer undesirable effects . Prostaglandins F2a and E are metabolized in the vessels of the lungs, kidneys, spleen, adipose tissue and intestines. 14

15. Drugs predominantly affecting the contractile activity of myometrium Agents increasing the contractile activity of the myometrium (myometrial stimulants) Prostaglandin drugs Dinoprost It is used for medical abortions ( for gestation periods up to 15 weeks. They are administered extramnially , and after 15 weeks intraamnially ). In case of weakness of labor activity, it is administered intravenously . Side effects: bronchospasm, ↑ motor skills Gastrointestinal tract and causes diarrhea, arrhythmias, fluctuations in blood pressure. Children have retinal hemorrhages (40%). 15

16. Drugs predominantly affecting the contractile activity of myometrium Agents increasing the contractile activity of the myometrium (myometrial stimulants) Prostaglandin drugs Dinoprost Unlike dinoprost↓ bronchial tone, ↓ AD. It is used to stimulate labor , administered orally and intravenously , it is possible to use a vaginal gel ( prostin E2). For medical termination of pregnancy, the drug is administered intravenously Side effects: nausea, vomiting, diarrhea, body temperature, headache, chills, blood pressure . Prostaglandins can also cause excessive stimulation of myometrial contractions with impaired blood supply to the uterus and placenta . 16 Contraindications • discrepancy between the size of the pelvis and the fetus, • in the transverse and oblique position of the fetus, • in the presence of postoperative scars on the uterus and malformations of the uterus.

17. Agents decreasing the contractile activity of the myometrium ( tocolytic drugs; myometrial relaxants)   Predominantly stimulating  β 2 - adrenoceptors Fenoterol Salbutamol Hexoprenaline ( ginipral ) Drugs that decrease the contractile activity of the myometrium   include agents that stimulate β 2 -adrenoceptors of the uterus, such as  fenoterol   ( partusisten ) and  salbutamol.  These drugs are indicated to delay or prevent premature labor. These drugs are highly effective. But their effect is not limited to the myometrium. 17

18. Agents decreasing the contractile activity of the myometrium ( tocolytic drugs; myometrial relaxants)   Predominantly stimulating  β 2 - adrenoceptors Hexoprenaline ( ginipral ) has a long-lasting effect . Effects : decreased myometrial tone, improved blood circulation, ↓ diastolic pressure . β2-adrenomimetics are ineffective when opening the cervix by more than 2 cm and with strong and frequent contractions of the uterus. 18 Indications for use: premature birth (before 37 weeks), improvement of fetoplacental blood flow, to eliminate Intrauterine fetal hypoxia in women with late toxicosis , reduction of diastolic pressure. Side effects: tremor (hands), skeletal muscle tone, vasodilation, headache , tachycardia, allergic reactions, diuresis .

19. Agents decreasing the contractile activity of the myometrium ( tocolytic drugs; myometrial relaxants) Drugs used for general anesthesia Sodium hydroxybutyrate they are used to weaken excessive contractions, drug-induced sleep in order to rest the woman in labor . Other agents The contractile activity of the myometrium can also be reduced with parenteral administration of Magnesium sulfate . This is due to the fact that magnesium sulfate prevents the penetration of calcium ions necessary for contraction into the cells of the myometrium. It is also believed that magnesium sulfate has a direct suppressive effect on the myometrium. 19

20. II Drugs predominantly increasing the tone of the myometrium  Agents of plant origin (alkaloids and ergot preparations) Ergometrine Ergotamine Ergot extract Ergotalum They are contained in the dormant form of the fungus Claviceps purpurea , which parasitizes rye . 20 Effects: reduce pulse fluctuations of cerebral vessels (effective for migraines ); cause prolonged tonic contraction muscles of the uterus. With parenteral administration , all drugs act instantly. Ergot alkaloids are excreted by the mammary glands. Side effects: Nausea, vomiting, diarrhea, headache , hallucinations.

21. II Drugs predominantly increasing the tone of the myometrium  Agents of plant origin (alkaloids and ergot preparations) Overdose: Acute poisoning: motor excitement, convulsions ("angry convulsions"), epigastric pain, tachycardia . Chronic poisoning ( ergotism ): a violation of the nutrition of tissues (especially limbs) with the development of gangrene - " Antonov fire", also mental disorders. 21

22. 22 Alkaloid Increase in the myometrium tone α- Adrenoblocking properties Peripheral vascular spasm (endothelial damage) Ergometrine High activity; rapid development of the effect; effective after oral administration Not found Low activity Ergotamine Ergosine Ergocriptine Ergocornine High activity (especially ergotamine); significant latent period; not effective if administered orally Marked High activity (especially ergotamine) Comparative characteristics of ergot alkaloids

23. II Drugs predominantly increasing the tone of the myometrium Synthetic drugs Cotarninum 23 Synthetic drugs used to increase the tone of the myometrium include  cotarninum   ( stipticine ). According to its structure, it is the derivative of dihydroisoquinoline . This agent is used for the treatment of uterine bleeding. It is administered orally and parenterally.

24. Different medicines Myotropic antispasmodics – drotaverine Prostaglandins – dinoprost 24