All of the following options suppress lactation, except for which one?

MP CHO-2020

Pharmacology

Medium

Appeared in: MP CHO-2020

Explanation

Injection Methergin (Methylergometrine) is an ergot alkaloid, classified as a uterotonic agent.
Its primary medical use is to cause uterine contractions to prevent and treat postpartum hemorrhage (PPH) by constricting uterine blood vessels after childbirth.
Methergin does not act on the dopamine-prolactin pathway and therefore has no physiological mechanism to suppress lactation.
It is commonly administered in the third stage of labor, a period when lactation is naturally beginning, without interfering with the process.

Option A: Cabergoline is a potent dopamine D2 receptor agonist and is considered a first-line drug for suppressing lactation by inhibiting prolactin secretion.
Option B: High doses of Pyridoxine (Vitamin B6) are used to suppress lactation. It is thought to work by increasing dopamine production, which in turn inhibits prolactin.
Option C: Mixogen contains an estrogen component. Estrogens suppress lactation by directly inhibiting the milk-producing effects of prolactin on the breast tissue.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Pharmacological agents affecting lactation as background academic context rather than a clinical decision trigger.
Nurses must differentiate between drugs used for postpartum hemorrhage (like Methergin) and those for lactation suppression, as their indications and contraindications are distinct.
Administering a lactation suppressant to a mother who wishes to breastfeed can cause distress and interfere with bonding. Conversely, failing to provide suppression when medically indicated or desired can lead to painful breast engorgement and mastitis.
It is crucial to assess a patient's desire to breastfeed before administering any medication that could affect lactation.

How to Approach the Question

First, identify the core of the question. It asks for the medication that is an exception to the rule of 'suppressing lactation'. This means you need to find the one drug that does NOT stop milk production.
Review each option and recall its primary pharmacological action.
Evaluate Option A (Cabergoline): This is a well-known dopamine agonist used specifically to stop lactation by inhibiting prolactin.
Evaluate Option B (Pyridoxine): Recall that Vitamin B6 is linked to dopamine synthesis and is used for lactation suppression.
Evaluate Option C (Mixogen): Identify this as a hormonal preparation containing estrogen, which is known to inhibit lactation.
Evaluate Option D (Methergin): Recognize this as a uterotonic, a drug used to contract the uterus and control bleeding, not to affect lactation.

Concept Tested & Keywords

QiEZFkXGLy_L-zH2VqmYwU

E6 Midwifery Obstetrics and Gynecology Nursing Sandeep Kaur p. 7-12

E6 Pharmacology KD Tripathi Essentials 9e Part 1 p. 288-290