Which option represents a combination that includes a carbonic anhydrase inhibitor with a beta blocker?

Which option represents a combination that includes a carbonic anhydrase inhibitor with a beta blocker?

• A. Dorzolamide 2% with Timolol
• B. Pilocarpine 2%
• C. Dorzolamide 2% alone
• D. Brinzolamide 1%

Answer: (A)

A dual mechanism to lower aqueous humor production is most effective for reducing intraocular pressure. A carbonic anhydrase inhibitor like dorzolamide cuts fluid formation in the ciliary processes by blocking carbonic anhydrase, while a beta blocker like timolol lowers production further by reducing cAMP in the same tissue. Together, they provide an additive effect in a single drop when given as a fixed combination. So, the option that includes both dorzolamide and timolol fits this requirement, giving both a carbonic anhydrase inhibitor and a beta blocker. The other choices do not combine these two actions: pilocarpine is a cholinergic agent that mainly increases outflow, not a CAI or beta blocker; dorzolamide 2% alone is just the CAI without a beta blocker; brinzolamide 1% is another CAI given alone.

A dual mechanism to lower aqueous humor production is most effective for reducing intraocular pressure. A carbonic anhydrase inhibitor like dorzolamide cuts fluid formation in the ciliary processes by blocking carbonic anhydrase, while a beta blocker like timolol lowers production further by reducing cAMP in the same tissue. Together, they provide an additive effect in a single drop when given as a fixed combination.

So, the option that includes both dorzolamide and timolol fits this requirement, giving both a carbonic anhydrase inhibitor and a beta blocker. The other choices do not combine these two actions: pilocarpine is a cholinergic agent that mainly increases outflow, not a CAI or beta blocker; dorzolamide 2% alone is just the CAI without a beta blocker; brinzolamide 1% is another CAI given alone.