What is the mechanism of the 'itching' or pruritus often felt by patients after an injection of Morphine?
Show answer and explanation
Correct answer: Non-immunologic histamine release from mast cells
Morphine can cause direct, non-immunologic degranulation of mast cells, releasing histamine. This results in vasodilation (hypotension), bronchodilation (rarely), and significant itching, which can often be managed with antihistamines.
Keep practicing
More Opioids questions
- Why is Codeine often considered a 'prodrug'?
- Which of the following is a mixed agonist-antagonist that can precipitate withdrawal in a patient already physically dependent on a full Mu…
- Which opioid is commonly used in the form of a transdermal patch for the management of chronic, severe pain?
- Opioid-induced 'chest wall rigidity' is a potential complication most commonly associated with the rapid IV administration of which drug?
- Methylnaltrexone is specifically indicated for which of the following conditions?
- Which opioid has an extremely short half-life (approx. 3-4 minutes) because it is rapidly metabolized by non-specific tissue and plasma est…