What are the two fixed combinations with beta blockers?

• A. Dorzolamide 2% - Timolol 0.5% (Cosopt, Cosopt PF), Brimonidine 0.2% - Timolol 0.5% (Combigan)
• B. Dorzolamide 2% - Timolol 0.5% (Cosopt, Cosopt PF), Latanoprost 0.005% (Xalatan)
• C. Brimonidine 0.2% - Timolol 0.5% (Combigan), Latanoprost 0.005% (Xalatan)
• D. Dorzolamide 2% - Brimonidine 0.2% (Cosopt Brimonidine)

Answer: (A)

Fixed combinations with a beta blocker are bottles that pair timolol with another antiglaucoma drug, combining two mechanisms to lower intraocular pressure in one drop. The two products that fit this description are the dorzolamide-timolol combination (Cosopt, with Cosopt PF as the preservative-free version) and the brimonidine-timolol combination (Combigan). Dorzolamide is a carbonic anhydrase inhibitor and timolol is a beta blocker; together they provide additional IOP reduction. Brimonidine is an alpha-2 agonist that also reduces aqueous production (and can modestly affect outflow) when paired with timolol. These two are the standard fixed combinations that include a beta blocker. The other options mix in a prostaglandin (latanoprost) or involve a non–timolol pairing, so they don’t meet the criterion of two fixed combinations with a beta blocker.