Dosing of fixed combinations without beta blockers when used as an adjunct is:

• A. QID
• B. BID
• C. QD
• D. QHS

Answer: (B)

When a fixed combination that does not contain a beta blocker is used as an adjunct, dosing it twice daily is typically chosen. The components in these mixes (for example, brinzolamide with brimonidine) have a duration of effect that benefits from two administrations per day to maintain consistent intraocular pressure lowering throughout the 24-hour period. Using once daily often leaves daytime IOP fluctuations insufficiently controlled, while four times daily adds unnecessary burden and increases chances of local side effects without a meaningful gain in control. Dosing twice daily strikes a balance between effective IOP management and patient adherence.