SBA — Single Best Answer · Review
Question 483
Pharmacology → General
Classification
Question
SSBAQuestion Header
A patient receives morphine for severe pain. Which combination of physiological effects is most characteristic?
Question Stem
Select the single best answer.
Options
A
Direct myocardial depression, reduced ADH production and increased systemic vascular resistance
B
Tachycardia, reduced histamine release and reduced ADH production
C
No direct myocardial depression, possible bradycardia, reduced systemic vascular resistance and increased ADH production
D
Increased systemic vascular resistance, bronchodilatation and reduced ADH production
E
Direct myocardial depression, bronchodilatation and increased systemic vascular resistance
Explanation
Morphine does not directly depress the myocardium, although bradycardia may occur. It can produce hypotension by reducing systemic vascular resistance, partly through histamine release, and it increases antidiuretic hormone production.
Option Validity
A) Morphine does not cause direct myocardial depression; systemic vascular resistance falls and ADH production increases.
B) Morphine may cause bradycardia, histamine release contributes to its vascular effects, and ADH production increases.
D) Morphine reduces rather than increases systemic vascular resistance, histamine release may cause bronchospasm, and ADH production increases.
E) Morphine does not directly depress the myocardium and does not characteristically increase systemic vascular resistance or cause bronchodilatation.
Further Reading
Saxena R. Textbook for MRCOG-1. Chapter 12: Pharmacology. Analgesics, p.347.