SBA — Single Best Answer · Review
Question 439
Pharmacology → General
Classification
Question
SSBAQuestion Header
Following administration of diazepam, a patient develops clinically important respiratory depression. The pharmacological effect of diazepam involves increased neuronal chloride conductance. Which drug most specifically antagonises this benzodiazepine effect?
Question Stem
Select the single best answer.
Options
A
Naloxone
B
Phentolamine
C
Propranolol
D
Clonidine
E
Flumazenil
Explanation
Diazepam is a benzodiazepine with hypnotic, amnesic and anticonvulsant actions mediated through GABA receptors, increasing neuronal chloride conductance. Respiratory depression due to benzodiazepine action can be antagonised by flumazenil.
Option Validity
A) Naloxone reverses opioid effects rather than benzodiazepine effects.
B) Phentolamine is an alpha-adrenoceptor blocker and does not antagonise benzodiazepine effects.
C) Propranolol is a non-selective beta-adrenoceptor antagonist.
D) Clonidine is a centrally acting alpha-2 receptor agonist and does not antagonise benzodiazepine effects.
Further Reading
Saxena R. Textbook for MRCOG-1. Chapter 12: Pharmacology. Hypnotics, Sedatives and Anxiolytics, p.345.