Flashcards in Obstetric & Gynaecology Deck (21):
Use of Dinoprostone
Prostaglandin E2 stimulates myometrium to contract similarly to the contraction during labour hence stimulates labour
Contraindication of dinoprostone
Active cardiac/pulmonary disease
History of c-section or difficult/traumatic labour
Routes of delivery for dinoprostone
Gel 1ml, 2ml (Prostin)
Vaginal pessary 10mg (Propess)
Advantages of dinoprostone pessary over gel
Less Vaginal examinations required
Reduced hospital costs
Oxytocin mode of action
Oxytocin promotes contractions by increasing the intracellular Ca2+, which in turn activates myosin's light chain kinase.. Oxytocin has specific receptors in the muscle lining of the uterus and the receptor concentration increases greatly during pregnancy, reaching a maximum in early labor at term.
Contraindication of oxytocin
1. Disproportion that is more than borderline.
2. Where the lie is other than longitudinal
3. In cases of previous caesarean section for contracted pelvis or who have failed in a previous trail of labor for disproportion.
4. Where a tumor occupies the pelvis.
5. When vaginal delivery is contraindicated in conditions like major degree placenta previa, vasa previa, cord presentation and prolapse, invasive carcinoma of cervix and infections like active herpes genitalis.
6. Previous classical caesarean section.
7. Regular contractions.
8. Unification surgery for uterine didelphis.
Side effects of oxytocin
Nausea & Vomiting
Drugs for induction or augmentation of labour
Drugs for prevention and treatment of hemorrhage
Carboprost (Deep IM 250ug)
Oxytocin with ergometrine (Syntometrine)
Mechanism of action of carboprost
Carboprost is a synthetic prostaglandin. It binds the prostaglandin E2 receptor, causing myometrial contractions, casuing the induction of labour or the expulsion of the placenta. Prostaglandins occur naturally in the body and act at several sites in the body including the womb (uterus). They act on the muscles of the womb, causing them to contract.
Contraindications of carboprost
Untreated pelvic disease
Side effects of carboprost
erythema at injection site
Prophylaxis of PPH at caesarian section
Carbetocin 100mcg/ml (Pabal)
Mode of action of ergometrine
Ergonovine directly stimulates the uterine muscle to increase force and frequency of contractions. With usual doses, these contractions precede periods of relaxation; with larger doses, basal uterine tone is elevated and these relaxation periods will be decreased. Contraction of the uterine wall around bleeding vessels at the placental site produces hemostasis. Ergonovine also induces cervical contractions. The sensitivity of the uterus to the oxytocic effect is much greater toward the end of pregnancy. The oxytocic actions of ergonovine are greater than its vascular effects.
Syntometrine consists of:
Oxytocin 5 unit per 1 ml
Ergometrine maleate 500 microgram per 1 ml
Mode of action of carbetocin
Oxytocin receptor agonist
Side effects of carbetocin
anaemia; back pain
Contraindications of carbetocin
Induction of abortion
Methotrexate in conjunction with misoprostol
What is misoprostol
Prostaglandin E1 analogue works in this case via selective binding to the EP-2/EP-3 prostanoid receptors.