Which of the following is NOT an adverse effect of morphine?

Appeared in: AIIMS BBSR SNO - 2019

Explanation

'Respiratory stimulation' because it is the opposite of morphine's actual effect on the respiratory system.
Morphine is a central nervous system (CNS) depressant that acts on the respiratory centers in the brainstem.
This action decreases the sensitivity of these centers to carbon dioxide, leading to a slower breathing rate and reduced depth of breathing, an effect known as respiratory depression.
Respiratory depression is the most dangerous adverse effect of morphine and can be fatal in cases of overdose.

Option A: Euphoria, a feeling of intense happiness or well-being, is a well-known psychological effect of morphine. This effect is a primary reason for its potential for abuse and addiction.
Option C: Nausea and vomiting are very common adverse effects of morphine. They occur due to the stimulation of the chemoreceptor trigger zone (CTZ) in the medulla of the brain.
Option D: Morphine can cause the release of histamine from mast cells. This leads to common side effects like itching (pruritus), skin flushing, hives (urticaria), and can contribute to hypotension (low blood pressure).

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Adverse effects of Morphine as background academic context rather than a clinical decision trigger.
A nurse's primary responsibility when administering morphine is to monitor for respiratory depression. This includes checking the respiratory rate, depth, and oxygen saturation before and after administration.
Any respiratory rate below 12 breaths per minute in an adult patient receiving morphine should be reported immediately, and further doses may be withheld.
What if? If a patient receiving morphine develops a respiratory rate of 8 breaths per minute and is difficult to arouse, the nurse's first action should be to attempt to stimulate the patient and, if unsuccessful, prepare to administer an opioid antagonist like naloxone and call for emergency assistance.

How to Approach the Question

First, identify the keyword 'NOT' in the question. This indicates you are looking for the option that is false or does not belong.
The question asks what is NOT an adverse effect of morphine.
Recall the pharmacological class of morphine: it is an opioid analgesic and a potent CNS depressant.
Evaluate each option based on this core knowledge:
Does morphine cause euphoria? Yes, it's a known CNS effect.
Does morphine cause respiratory stimulation? No, as a CNS depressant, it causes respiratory depression.

Concept Tested & Keywords

Concept Tested: Adverse effects of Morphine
Stem keywords: morphine, adverse effect
Lead-in keywords: NOT
Negative lead-in flag: The question asks to identify the option that is NOT an adverse effect of morphine.

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Practise the full AIIMS BBSR SNO - 2019

Attempt every question from this paper in a timed mock, then review the full solution for each one.