The drug used for induction of labour is ?

RRB Nsg. Superintendent-21 July 2019 (Shift-2nd)

Pharmacology

Easy

Appeared in: RRB Nsg. Superintendent-21 July 2019 (Shift-2nd)

Explanation

Oxytocin is the drug of choice for inducing labor as it is a hormone that stimulates rhythmic contractions of the pregnant uterus, mimicking the natural process.
It has a short half-life, which allows its effects to be precisely controlled by adjusting the intravenous infusion rate and can be quickly stopped if uterine hyperstimulation or fetal distress occurs.
Unlike ergot alkaloids, low-dose oxytocin allows for periods of complete uterine relaxation between contractions, which is crucial for maintaining blood flow to the placenta and preventing fetal asphyxia.

Option A: It is an ergot alkaloid that causes sustained, tetanic uterine contractions without a relaxation phase, which can lead to fetal asphyxia and uterine rupture.
Option C: This hormone inhibits uterine contractions and helps maintain pregnancy. Its levels naturally fall before labor begins.
Option D: This is a brand name for methylergometrine, an ergot alkaloid similar to ergometrine. It causes powerful, sustained contractions and is contraindicated for labor induction.

Visual 1: Diagram: Mechanism of Oxytocin. Illustrating how oxytocin binds to myometrial receptors to initiate uterine contractions.
Visual 2: Comparison Table: Oxytocin vs. Ergot Alkaloids. Highlighting the differences in their effects on uterine contractions, primary uses (labor induction vs. PPH), and contraindications.

Clinical Relevance

Nursing practice connection: Knowing Pharmacology of Uterine Stimulants (Oxytocics) helps nurses interpret findings accurately and avoid errors in routine assessment, medication administration, and patient teaching.
Administering oxytocin requires continuous electronic fetal monitoring and uterine activity monitoring to immediately detect signs of fetal distress or uterine tachysystole (more than five contractions in 10 minutes).
Nurses must use an infusion pump for precise dose titration and have an emergency plan to stop the infusion and provide supportive care if adverse effects occur.
What if? If a patient develops uterine hyperstimulation (tachysystole with fetal heart rate changes), the first nursing action is to stop the oxytocin infusion immediately, turn the patient to her side, and administer oxygen if prescribed.

How to Approach the Question

First, understand the question's core concept: identifying a drug that starts or induces labor.
Recall the key hormones and drugs related to pregnancy. Oxytocin is the primary hormone for contractions, while progesterone maintains pregnancy.
Differentiate between drugs used for labor induction versus those for postpartum complications. Ergometrine and Methergine are known for controlling bleeding after birth.
Eliminate Progesterone because it prevents contractions.
Eliminate Ergometrine and Methergine because they are used for postpartum hemorrhage and their contraction pattern is unsafe for a fetus during labor.
This leaves Oxytocin as the only logical and correct choice for safely inducing labor.

Concept Tested & Keywords

QS4zzoQruh3xNDwB8KaYbu