Drugs 2

Question 1

Progesterone

Answer 1

• Prevention of preterm labor; used to reduce the risk of spontaneous preterm birth in selected women
• Tocolytic therapy: inhibiting uterine contractions

Question 2

Tocolytic agents

Answer 2

• adrenergic receptor agonists
• MgSO4
• Ca channel blockers
• COX inhibitors
• oxytocin-receptor antagonists
• NO donors

Question 3

Adrenergic B receptor agonists

Answer 3

• may delay births but only for the 1st 48 hours of treatment
• adverse maternal effects: tachycardia, hypotension, pulmonary edema

Question 4

Calcium Channel blocker

Answer 4

• Nifedipine

- used most commonly to delay contractions

Question 5

COX inhibitors

Answer 5

• Indomethacin
• Used off label to prevent preterm labor
• Also inhibit platelet functions and induce ductus ateriosus closure in utero; should not be used in term pregnancies

Question 6

Dinoprostone

Answer 6

• Prostaglandin
• Use: facilitate labor by promoting ripening and dilation of the cervix.
• Major adverse effect: uterine hyperstimulation

Question 7

Misprostol

Answer 7

• Prostaglandin, synthetic derivative of PGE1
• Use: cervical ripening and labor induction, postpartum hemorrhage, treatment of incomplete or missed abortion
• Adverse effects: uterine hyperstimulation, uterine rupture

Question 8

Oxytocin

Answer 8

• Drug of choice for labor induction
• Use: induce labor, augment slow moving labor, dyfunctional labor, or prophylaxis of postpartum hemorrhage (given immediately after delivery to maintain uterine contractions)
• Adverse effects: uterine hyperstimulation or development of uterine tetany
• Short T1/2
• Structurally similar to vasopresisn–at high doses, will also act as antidiuretic–>convulsions, coma, death

Question 9

Ergonovine

Answer 9

Use: prevention and treatment of postpartum and post abortion hemorrhage
Mechanism: affects uterine smooth muscle to produce sustained contraction
Side effects: nausea and vomiting, elevated BP, decreased pain threshold