PPT_Chapter_34.ppt - Uterine Drugs Chapter 34 Copyright \u00a9 2013 Wolters Kluwer Health | Lippincott Williams Wilkins Actions of Oxytocic Drugs Oxytocin

PPT_Chapter_34.ppt - Uterine Drugs Chapter 34 Copyright...

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Unformatted text preview: Uterine Drugs Chapter 34 Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Actions of Oxytocic Drugs Oxytocin Endogenous hormone produced by the posterior pituitary gland Uterine-stimulating properties, especially in a pregnant uterus Sensitivity of the uterus to oxytocin increases as pregnancy progresses Also has antidiuretic and vasopressor effects Exact mechanism of action is not known Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Actions of Oxytocic Drugs Ergonovine and methylergonovine Increase strength, duration, and frequency of uterine contractions Decrease the incidence of uterine bleeding Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Actions of Oxytocic Drugs Carboprost Similar to naturally occurring prostaglandin F2 Stimulates uterine smooth muscle, resulting in contractions Dinoprostone Synthetic preparation of prostaglandin F2 Increases uterine contractions by stimulating the smooth muscle of the uterus Promotes cervical ripening by direction action on the local receptors and relaxing the smooth muscles of the uterus Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Actions of Oxytocic Drugs Mifepristone Once widely known as RU-486 Synthetic steroid that has both antiprogesterone and antiglucocorticoid activity Action depends on when given If given within 72 hours of unprotected intercourse, prevents implantation and acts like an emergency contraceptive In abortion, ultimately causes menstrual bleeding and termination of the pregnancy Also ripens the cervix Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Uses of Oxytocic Drugs Oxytocin IV to start or improve labor contraction for an early vaginal delivery of the fetus Management of inevitable or incomplete abortion IM during the third stage of labor to produce uterine contraction and control postpartum bleeding and hemorrhage Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Uses of Oxytocic Drugs Ergonovine and methylergonovine After delivery of the placenta Used to prevent postpartum and postabortal hemorrhage caused by uterine atony Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Uses of Oxytocic Drugs Carboprost Terminate a pregnancy between gestational weeks 13 and 20 Also used for postpartum uterine hemorrhage Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Uses of Oxytocic Drugs Dinoprostone Suppository used to terminate a pregnancy from week 12 through 20 Evacuate the uterine contents in the event of a missed abortion or intrauterine fetal death up to 28 weeks Cervical gel and vaginal insert to ripen the cervix Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Uses of Oxytocic Drugs Mifepristone In combination with misoprostol to terminate an intrauterine pregnancy through day 49 of pregnancy Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Adverse Reactions of Oxytocic Drugs Oxytocin Fetal bradycardia Uterine rupture Uterine hypertonicity Nausea and vomiting Cardiac arrhythmias Anaphylactic reactions Continuous IV infusion may cause water intoxication if patient is also receiving fluids by mouth Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Adverse Reactions of Oxytocic Drugs Oxytocin Managing adverse reactions Stop infusion if contractions are frequent, prolonged, or excessive Patient may be placed on her side and given supplemental oxygen Fluid intake and output are measured Monitor patient for signs of fluid overload Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Adverse Reactions of Oxytocic Drugs • Ergonovine – Nausea and vomiting – Elevated blood pressure “Ergotism” — Severe overdose of ergonovine • Methylergonovine – Nausea and vomiting – Hypertension associated with seizure or headache Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Adverse Reactions of Oxytocic Drugs Carboprost Vomiting Diarrhea Nausea Temperature elevation Flushing Occasionally, endometriosis If retain bits of the placenta, uterine bleeding Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Adverse Reactions of Oxytocic Drugs Dinoprostone Depend on the dosage form Suppository: vomiting, temperature elevations, diarrhea, nausea, headache, shivering and chills, drop in diastolic blood pressure Gel: uterine contractile abnormalities, GI disturbances, fetal heart rate abnormalities Insert: uterine hyperstimulation, fetal distress Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Adverse Reactions of Oxytocic Drugs Mifepristone Dizziness Fatigue Headache Abdominal cramping or pain Diarrhea Nausea Vomiting Back pain Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Contraindications, Precautions, and Interactions of Oxytocics Oxytocin Contraindications: Known hypersensitivity Cephalopelvic disproportion Unfavorable fetal position or presentation Obstetric emergencies Fetal distress when delivery is not imminent Severe toxemia Hypertonic uterus Total placenta previa While inducing labor when vaginal delivery is contraindicated Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Contraindications, Precautions, and Interactions of Oxytocics Oxytocin Not ordinarily a risk to the fetus when administered as indicated Interactions: vasopressor Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Contraindications, Precautions, and Interactions of Oxytocics Ergonovine and methylergonovine Contraindications: Known hypersensitivity Hypertension Before delivery of the placenta Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Contraindications, Precautions, and Interactions of Oxytocics Ergonovine and methylergonovine Contraindications: Ergonovine: serotonin receptor agonists, vasoconstrictors, beta-blockers, antiangina drugs, antiretrovirals, SSRIs, SNRIs, inhibitors of CYP3A4 Methylergonovine: known hypersensitivity, hypertension, preeclampsia, to induce labor Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Contraindications, Precautions, and Interactions of Oxytocics Ergonovine and methylergonovine Precautions: Ergonovine: heart disease, obliterative vascular disease, liver or kidney disease, lactation Methylergonovine: renal or hepatic impairment Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Contraindications, Precautions, and Interactions of Oxytocics Ergonovine and methylergonovine Interactions: Should not be administered with each other or other ergot alkaloids Methylergonovine: vasopressors, heavy cigarette smokers Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Contraindications, Precautions, and Interactions of Oxytocics Carboprost Contraindications: Known hypersensitivity to drug or prostaglandins; acute pelvic inflammatory disease; active cardiac, pulmonary, renal, or hepatic disease Precautions: Hypotension Interactions: Other oxytocic drugs Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Contraindications, Precautions, and Interactions of Oxytocics Dinoprostone Contraindications: Known hypersensitivity to drug or prostaglandins; acute pelvic inflammatory disease; active cardiac, pulmonary, renal, or hepatic disease Cervical gel and vaginal insert: patients in whom prolonged contractions of the uterine are inappropriate Vaginal insert: when delivery is not imminent and there is suspected or definite evidence of fetal distress, unexplained vaginal bleeding Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Contraindications, Precautions, and Interactions of Oxytocics Dinoprostone Interactions: Other oxytocic drugs Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Contraindications, Precautions, and Interactions of Oxytocics • Mifepristone – Contraindications: ectopic pregnancy; undiagnosed adnexal mass; IUD in place; chronic adrenal failure; concurrent long-term corticosteroid use; hemorrhagic disorders; concurrent anticoagulant therapy; history of allergy to mifepristone, misoprostol, or prostaglandins – Interactions: medications that induce or inhibit cytochrome P450 3A4 Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Patient Management Issues with Oxytocics Oxytocin Monitor blood pressure, pulse, and respiratory rate frequently Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Patient Management Issues with Oxytocics Ergonovine and methylergonovine Monitor vital signs Note character and amount of vaginal bleeding Notify health care provider if abdominal cramping is moderate to severe Ergonovine: usually given IM, but may be given IV Methylergonovine: IM; if given IV, then must be over 1 minute or more while monitoring blood pressure Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Patient Management Issues with Oxytocics Carboprost Only administered in a hospital that can provide immediate intensive medical and surgical care Dinoprostone Suppository should be inserted high in the vagina After insert has been put in place, may remain in supine position for 2 hours Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Patient Management Issues with Oxytocics Mifepristone Follow-up visit approximately 14 days after dose to ensure that pregnancy has been terminated Must follow treatment schedule and keep followup appointments Vaginal bleeding and cramping will occur If treatment fails, risk of fetal malformation and a surgical termination may be necessary Patient can get pregnant after the termination and even prior to menses returning Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Educating the Patient and Family About Oxytocic Drugs Treatment regimen should be explained Educate to report adverse reactions Drugs will cause uterine cramping or vaginal bleeding If taken to end a pregnancy, prolonged heavy bleeding is not proof of a complete abortion, and follow-up appointments should be kept Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins ...
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