True or False: We often double-up within the same class of meds.

• A. True
• B. False
• C. Not applicable
• D. Sometimes

Answer: (B)

We don’t double up within the same class because medications in one class share the same mechanism, and adding a second drug with the same mechanism typically doesn’t provide much extra lowering of intraocular pressure. There’s a ceiling to how much a single mechanism can reduce IOP, so the incremental benefit of a second drug from the same class is small. At the same time, the total drug burden increases the risk of side effects—systemic effects like dizziness or bradycardia with certain classes, and local eye symptoms such as irritation or conjunctival redness—and makes adherence harder.

In practice, if a patient isn’t achieving target IOP, clinicians usually add a drug from a different class that works through a complementary mechanism—for example, a prostaglandin analog to increase outflow via the uveoscleral pathway or a carbonic anhydrase inhibitor to reduce production—thereby achieving a greater combined effect with a better safety/adherence profile.