TYK150: Difference between revisions
m 1 revision imported |
m Text replacement - "<p style="text-align: center;"> About Test Your Knowledge</p>" to "<p style="text-align: center;"> About Test Your Knowledge</p> Category:TYK" |
||
| Line 42: | Line 42: | ||
<p style="text-align: center;">[[TYK149|<Prev Question]] --- [[TYK151|Next Question>]]</p> | <p style="text-align: center;">[[TYK149|<Prev Question]] --- [[TYK151|Next Question>]]</p> | ||
<p style="text-align: center;">[[TYK About | About Test Your Knowledge]]</p> | <p style="text-align: center;">[[TYK About | About Test Your Knowledge]]</p> | ||
[[Category:TYK]] | |||
Latest revision as of 02:38, 25 September 2026
Postoperative hypotension following pheochromocytoma resection may be refractory to α-agonists in patients who have been treated with phenoxybenzamine because:
a) Phenoxybenzamine has a prolonged half-life
b) Renal clearance of phenoxybenzamine is significantly reduced in these patients
c) Adrenoreceptor blockade is permanent and new receptors must be generated
d) Residual catecholamines compete with α-agonists at the nerve terminals
e) Volatile agents induce receptor destruction in the presence of phenoxybenzamine
Answer
Answer c.
Phenoxybenzamine is an irreversible, noncompetitive blocker of α- adrenoreceptors. Thus, effects outlast the pharmacokinetic half-life. Postoperative hypotension may be refractory to α-agonists until new receptors are generated.
Notes
- This question originally printed in the Pediatric Anesthesiology Review Topics kindle book series, and appears courtesy of Naerthwyn Press, LLC.
Keywords