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Question 443
Pharmacology → General
Classification
Question
SSBAQuestion Header
A pregnant patient in the third trimester has prolonged exposure to an NSAID. Which combination best reflects the pharmacological consequences described for this drug class?
Question Stem
Select the single best answer.
Options
A
Increased renal prostaglandin synthesis with increased renal blood flow and delayed ductal closure
B
Reduced renal prostaglandin synthesis with sodium retention and risk of premature ductal closure
C
Increased renal prostaglandin synthesis with sodium loss and fetal tachycardia
D
Selective opioid receptor blockade with fetal respiratory stimulation
E
Reduced renal prostaglandin synthesis with increased renal blood flow and fetal vasodilatation
Explanation
NSAIDs inhibit renal prostaglandin synthesis. This can cause sodium retention, reduced renal blood flow and possible renal failure. A further concern, particularly in the third trimester, is premature closure of the ductus arteriosus.
Option Validity
A) NSAIDs inhibit rather than increase renal prostaglandin synthesis, and premature rather than delayed ductal closure is the concern.
C) The direction of the renal prostaglandin effect is incorrect and the expected effect is sodium retention rather than sodium loss.
D) NSAIDs do not act through opioid receptor blockade.
E) Although renal prostaglandin synthesis is reduced, renal blood flow is reduced rather than increased.
Further Reading
Saxena R. Textbook for MRCOG-1. Chapter 12: Pharmacology. Analgesics, pp.346–347.