Side effect of morphine includes?

Appeared in: VSSC Nursing Officer - 2021

Explanation

Morphine is a potent opioid analgesic that acts as a central nervous system (CNS) depressant.
Its primary and most dangerous side effect is respiratory depression, which is caused by reducing the sensitivity of the brainstem's respiratory centers to carbon dioxide.
This action results in a dose-dependent decrease in both the rate and depth of breathing.
Death in acute morphine poisoning is most commonly due to respiratory failure.

Option A: This is incorrect. Morphine typically causes hypotension (a decrease in blood pressure), not an increase. This effect is due to the depression of the vasomotor center in the brainstem and the release of histamine, which causes vasodilation.
Option C: This is the opposite of morphine's effect. As a CNS depressant, morphine slows down respiratory function.
Option D: This option is incorrect because a significant and well-documented side effect of morphine is listed among the choices.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Pharmacological side effects of opioid analgesics (Morphine) as background academic context rather than a clinical decision trigger.
Nurses must assess a patient's respiratory rate, depth, and oxygen saturation before and after administering morphine to detect respiratory depression early.
A respiratory rate below 12 breaths/minute is a critical finding that requires immediate intervention, such as withholding the dose, stimulating the patient, and notifying the provider.
The triad of opioid overdose—coma, pinpoint pupils, and respiratory depression—is a medical emergency requiring immediate administration of naloxone.

How to Approach the Question

First, identify the drug class of the medication in the question. Morphine is a classic opioid analgesic.
Recall the primary mechanism of action for this drug class. Opioids are central nervous system (CNS) depressants.
Analyze the options in the context of CNS depression. A depressant effect would slow down bodily functions, not speed them up.
Evaluate each option: 'Increased blood pressure' and 'Increased respiratory rate' are stimulant effects and are inconsistent with a CNS depressant.
'Decreased respiratory rate' is a classic depressive effect and a well-known, major side effect of opioids.
Based on this reasoning, select the option that reflects a depressive action on the respiratory system.

Concept Tested & Keywords

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E6 Pharmacology Nurses Shanbhag 3e p. 160-162

E6 Pharmacology KD Tripathi Essentials 9e Part 2 pp. 136-138, 135-137

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