Which of the following side effects would you not expect from carbonic anhydrase inhibitors?

Carbonic anhydrase inhibitors, used primarily to lower intraocular pressure in conditions like glaucoma, can lead to a variety of side effects due to their systemic action. The correct answer identifies a side effect that is not associated with the medication's pharmacological effects.

Drowsiness is a possible effect, as carbonic anhydrase inhibitors can impact the central nervous system. A change in taste is also recognized as a potential side effect, particularly with oral formulations, as these drugs affect the electrolyte balance and can also alter the body's normal sensory perceptions. Frequent urination is another expected outcome since these medications can have a diuretic effect, leading to increased urination.

In contrast, changing the color of the iris is not a recognized side effect of carbonic anhydrase inhibitors. The color of the iris is primarily determined by genetics and melanin concentration, and while some medications like prostaglandin analogs can indeed cause changes in iris color, carbonic anhydrase inhibitors do not exert this effect. Thus, the correct option highlights a side effect that is unrelated to the action of carbonic anhydrase inhibitors, reinforcing the understanding that this class of drugs does not influence iris pigmentation.