In which patients Methyl ergometrine is contraindicated?

AIIMS Raipur NO- 2019 (shift 3rd)

Pharmacology

Medium

Appeared in: AIIMS Raipur NO- 2019 (shift 3rd)

Explanation

Methylergometrine is an ergot alkaloid that causes potent, generalized vasoconstriction (narrowing of blood vessels).
This vasoconstriction leads to a rapid and significant increase in systemic blood pressure.
In a patient with pre-existing heart disease, this sudden increase in blood pressure and cardiac workload can precipitate severe complications like acute heart failure, myocardial infarction, or a hypertensive crisis.
Therefore, heart disease and hypertension are absolute contraindications for the use of methylergometrine.

Option B: While caution may be warranted in severe cases, lung disease is not a primary or absolute contraindication for methylergometrine. The drug's main action is on vascular and uterine smooth muscle, not directly on the bronchioles.
Option C: Methylergometrine is metabolized in the liver. While severe liver dysfunction might impair drug clearance, leading to prolonged effects, it is not considered an absolute contraindication compared to the immediate and dangerous cardiovascular effects.
Option D: The kidneys are involved in the excretion of the drug. In patients with severe kidney disease, dosage adjustments might be necessary to prevent accumulation. However, this is a precaution, not an absolute contraindication like heart disease.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Pharmacology: Contraindications of Uterotonic Drugs as background academic context rather than a clinical decision trigger.
A nurse's primary safety check before administering methylergometrine is to assess the patient's blood pressure and review their history for any cardiac conditions or hypertension.
Administering methylergometrine to a hypertensive or cardiac patient is a serious medication error that can lead to life-threatening events.
What if? If a patient with a history of hypertension is experiencing postpartum hemorrhage, the nurse should anticipate an order for Oxytocin or a prostaglandin like Carboprost (with caution if asthmatic), and question any order for methylergometrine.

How to Approach the Question

First, identify the drug in the question: Methyl ergometrine.
Recall its drug class (ergot alkaloid) and primary mechanism of action (potent vasoconstrictor and uterine stimulant).
Think about the main physiological effect of vasoconstriction: it increases blood pressure.
Consider which patient population would be most endangered by a sudden, sharp rise in blood pressure.
Evaluate the options: A patient with heart disease is directly at risk from increased blood pressure and cardiac workload. Lung, liver, and kidney disease are less directly and immediately impacted by this specific mechanism.
Conclude that heart disease is the most critical contraindication.

Concept Tested & Keywords

Q6R2ja-X-4-hydFDVIRmd

E6 Pharmacology Katzung 16e pp. 461-463, 460-462