Which are the two generic formulations of oral CAIs?

• A. acetazolamide, methazolamide
• B. acetazolamide, dorzolamide
• C. timolol, latanoprost
• D. pilocarpine, brimonidine

Answer: (A)

The idea here is to know which glaucoma drugs are taken by mouth as carbonic anhydrase inhibitors. The two generic oral CAIs are acetazolamide and methazolamide. They work by inhibiting carbonic anhydrase in the ciliary body, which lowers bicarbonate formation and reduces the fluid pumped into the eye, thereby decreasing aqueous humor production and lowering intraocular pressure. This distinguishes them from other options: dorzolamide is a topical CAI, while timolol and latanoprost are a beta-blocker and a prostaglandin analogue, respectively. Pilocarpine and brimonidine are a cholinergic agent and an alpha-2 agonist, not CAIs. So acetazolamide and methazolamide are the correct pair because they are the two oral CAIs.