For diagnostic fundus examination requiring mydriasis without prolonged cycloplegia, which muscarinic antagonist has the shortest overall duration of action?
- A Atropine
- B Homatropine
- C Tropicamide ✓
- D Cyclopentolate
Correct answer: C. Tropicamide
Explanation
Tropicamide produces mydriasis lasting about 6 hours and cycloplegia for less than 6 hours, the shortest among routinely used ophthalmic antimuscarinics, making it ideal for brief fundoscopy. Cyclopentolate lasts around a day, homatropine several days, and atropine up to 7 to 10 days with cycloplegia lasting even longer, which is why atropine is reserved for uveitis and amblyopia therapy rather than quick examinations.
Reference: Katzung's Basic and Clinical Pharmacology, 15th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.