1 / 17

Chapter 64

Chapter 64. Drugs That Affect Uterine Function. Drugs That Affect Uterine Function. Three main categories: Uterine relaxants (tocolytics) Uterine relaxation Suppression of preterm labor Uterine stimulants (oxytocics) Uterine contraction Induction/augmentation of labor

kanan
Download Presentation

Chapter 64

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Chapter 64 Drugs That Affect Uterine Function

  2. Drugs That Affect Uterine Function • Three main categories: • Uterine relaxants (tocolytics) • Uterine relaxation • Suppression of preterm labor • Uterine stimulants (oxytocics) • Uterine contraction • Induction/augmentation of labor • Control of postpartum bleeding • Induction of abortion • Drugs used to decrease menorrhagia (heavy menstrual bleeding)

  3. Preterm Birth • Before 37 weeks’ gestation • Leading cause of infant morbidity and neonatal mortality • United States: 12.5% of all live births • Premature births account for 75% of all neonatal mortalities and 50% of congenital neurologic deficits • Most common neonatal respiratory distress syndrome

  4. Uterine Relaxants (Tocolytics) • Used to delay delivery • Average delay: only 48 hours • If used with glucocorticoids, the glucocorticoids can accelerate lung development • Also used to buy time to treat infection

  5. Control of Myometrial Contraction • Regulated by multiple mediators • Beta-adrenergic agonists • Oxytocin • Prostaglandins • Four classes of drugs: all decrease the availability of phosphorylated light chain • Beta-adrenergic antagonists, calcium channel blockers, cyclooxygenase (COX) inhibitors, and oxytocin-receptor antagonists

  6. Uterine Relaxants (Tocolytics) • Beta2-selective adrenergic agonist • Terbutaline (Brethine) • Beta2-selective adrenergic agonist • Not approved by FDA for this use • Nifedipine (Procardia, Adalat, Nifedical) • Can suppress labor for up to 48 hours • Efficacy equals that of terbutaline, and safety is superior

  7. Uterine Relaxants (Tocolytics) • Indomethacin (Indocin) • Second-line tocolytic • Higher risk for neonatal complications • Prolonged renal insufficiency, bronchopulmonary dysplasia, necrotizing enterocolitis, and periventricular leukomalacia • Nitroglycerin, a nitric oxide donor

  8. Uterine Relaxants (Tocolytics) • Atosiban • Oxytocin: receptor antagonist • Magnesium sulfate • High dose does not prevent or delay preterm birth but does increase infant mortality • Was previously used readily • Low-dose magnesium sulfate may reduce the risk of cerebral palsy without increasing mortality

  9. Drugs Used to Promote Cervical Ripening • Dinoprostone (Prepidil, Cervidil) • Dinoprostone gel • Dinoprostone vaginal inserts (Cervidil) • Misoprostol (Cytotec) • Not approved for this use

  10. Uterine Stimulants (Oxytocics) Prostaglandins: Dinoprostone and Misoprostol (can also induce labor) • Dinoprostone • Most widely used for cervical ripening • Shortens duration of labor, allows reduced dosage of oxytocin, decreases need for cesarean section • Can also induce abortion • Misoprostol • Not approved for cervical ripening • More convenient and less expensive than dinoprostone • Higher incidence of uterine tachysystone

  11. Uterine Stimulants (Oxytocics) • Three groups of uterine stimulants • Oxytocin • Ergot alkaloids • Prostaglandins

  12. Uterine Stimulants (Oxytocics) • Oxytocin (Pitocin) • Peptide hormone produced by the posterior pituitary • Increases the force, frequency, and duration of uterine contractions • Uterus becomes progressively more responsive to oxytocin throughout pregnancy • Facilitates labor, but unclear whether it can initiate labor

  13. Uterine Stimulants (Oxytocics) • Oxytocin (Pitocin) (cont’d) • Physiologic and pharmacologic effects • Uterine stimulation • Milk ejection • Water retention • Precautions and contraindications • Uterine rupture may occur • Women with active genital herpes • Adverse effect:water retention/intoxication

  14. Uterine Stimulants (Oxytocics) • Ergot alkaloids: ergonovine and methylergonovine • Dried preparation of Claviceps purpurea • Stimulate adrenergic, dopaminergic, and serotonergic receptors • Not used to induce labor (sustained contractions) • Can cause constriction of arterioles and veins and risk of severe hypertension • Used to control postpartum bleeding

  15. Uterine Stimulants (Oxytocics) • Ergot alkaloids: ergonovine and methylergonovine (cont’d) • Therapeutic uses • Postpartum bleeding (not responsive to oxytocin and carboprost tromethamine) • Augmentation of labor • Migraine • Adverse effects (IV administration) • Hypertension

  16. Uterine Stimulants (Oxytocics) • Carboprost tromethamine (Hemabate) • Preferred agent for controlling postpartum hemorrhage • Causes intense uterine contractions • Adverse effects • GI reactions • Vomiting and diarrhea • Fever • Vasoconstriction • Constriction of the bronchi

  17. Drugs for Menorrhagia • Tranexamic acid • Menorrhagia • Trauma patients • Adverse effects and interactions • NSAIDs • Combination oral contraceptives • Levonorgestrel-releasing intrauterine system

More Related