Pharmacology A.N.S. 5e81504e Which is the shortest acting mydriatic? A Atropine B Tropicamide C Cyclopentolate D Homatropine High-Yield Explanation Ans. (B) Tropicamide(Ref: Katzung 11/e p124)Atropine is longest acting (5-6 days) whereas tropicamide is the shortest acting (15-60 min) mydriatic.