What is the primary reason apraclonidine is not used for long-term therapy?

• A. Low efficacy
• B. Allergy rate and tachyphylaxis
• C. Significant systemic hypotension
• D. Interacts with contact lenses

Answer: (B)

Apraclonidine is used to lower IOP by stimulating alpha-2 receptors to reduce aqueous humor production, which makes it useful for short-term needs such as around procedures. The main reason it isn’t used for long-term therapy is that the eye commonly develops tachyphylaxis, so the IOP-lowering effect diminishes with continued use as receptors become desensitized. In addition, there is a relatively high rate of allergic conjunctivitis and conjunctival hyperemia with prolonged use, which often forces discontinuation. Because of these two factors—diminishing efficacy and ocular allergic reactions—apraclonidine isn’t suited for chronic management. The other issues mentioned, like systemic hypotension or lens interactions, are less central to its long-term use.