Autonomic Pharmacology USMLE Step 1 Practice Question
A 24-year-old man with allergic rhinitis uses an over-the-counter nasal spray containing oxymetazoline, a selective α1-agonist, three times daily for 5 days and develops rebound nasal congestion. On examination, he is hypertensive (BP 148/92 mmHg) and tachycardic (HR 108 bpm). Pupils measure 6 mm bilaterally with intact accommodation. He denies chest pain or dyspnea. Urinalysis shows no glycosuria, and serum electrolytes are within normal limits. Which of the following additional physiologic effects is most likely produced by this drug?
Answer choices
- AIncreased gastrointestinal motility
- BDetrusor contraction
- CDecreased peripheral vascular resistance
- DBronchoconstriction
- EMydriasis without cycloplegiaCorrect answer
- FIncreased salivary and lacrimal secretion
See the full explanation
Get the correct-answer rationale, why each distractor is wrong, the underlying mechanism, and high-yield associations — plus adaptive practice that targets your weak areas — with a free MedBoardPRO account.