Promethazine Flashcards
What is Promethazine and its primary uses in anesthesia?
Promethazine is a first-generation antihistamine with antiemetic, sedative, and anticholinergic properties, used for the prevention and treatment of PONV, preoperative sedation, enhancing opioid analgesia, alleviating pruritus, and managing mild allergic reactions.
How does Promethazine work as an antiemetic?
Promethazine blocks H1 and possibly dopamine receptors, reducing nausea and preventing vomiting by inhibiting emetic signals transmission to the brain’s vomiting center.
What are the sedative properties of Promethazine?
By crossing the blood-brain barrier and antagonizing H1 receptors in the brain, Promethazine induces sedation, aiding in preoperative sedation and anxiety relief.
Explain how Promethazine potentiates opioid analgesia.
Promethazine enhances the analgesic effects of opioids, potentially reducing opioid doses and associated side effects like respiratory depression.
How does Promethazine provide antipruritic relief?
Its antihistaminic action alleviates itching associated with medications or allergic reactions, enhancing patient comfort.
Describe the mechanism of action of Promethazine.
Promethazine blocks H1 histamine receptors and muscarinic acetylcholine receptors, leading to its antiemetic, sedative, and antipruritic effects, with weak α-adrenergic blocking properties potentially lowering blood pressure.
What are Promethazine’s key pharmacological properties?
As a phenothiazine derivative, Promethazine has antidopaminergic, antihistamine, and anticholinergic properties, useful for treating PONV, with alpha-adrenergic blocking properties and potential extrapyramidal symptoms.
What side effects are associated with Promethazine?
Side effects can include sedation, confusion, vision changes, anticholinergic effects like dry mouth, and extrapyramidal symptoms, with serious tissue injury possible on injection.
