True regarding acetazolamide is :
**Core Concept**
Acetazolamide is a carbonic anhydrase inhibitor used in the management of glaucoma, epilepsy, and altitude sickness. It works by inhibiting the enzyme carbonic anhydrase, which is involved in the regulation of pH and bicarbonate levels in the body.
**Why the Correct Answer is Right**
Carbonic anhydrase is an enzyme found in many tissues, including the kidneys, eyes, and brain. By inhibiting this enzyme, acetazolamide reduces the reabsorption of bicarbonate in the kidneys, leading to increased excretion of bicarbonate in the urine. This results in a decrease in blood pH, which is beneficial in conditions like glaucoma and epilepsy. Additionally, acetazolamide's ability to reduce bicarbonate levels helps to alleviate symptoms of altitude sickness by reducing the risk of acidosis.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect as acetazolamide is not a diuretic in the classical sense, although it does increase urine production. Its primary mechanism of action is through carbonic anhydrase inhibition, not through direct action on the kidneys' sodium or water reabsorption pathways.
**Option B:** This option is incorrect as acetazolamide does not have a significant effect on the renin-angiotensin-aldosterone system (RAAS). Its effects on blood pressure are indirect and result from its ability to decrease bicarbonate levels.
**Option C:** This option is incorrect as acetazolamide is not a direct inhibitor of the sodium-potassium pump (Na+/K+ ATPase). Its effects on electrolyte balance are indirect and result from its ability to increase potassium excretion in the urine.
**Clinical Pearl / High-Yield Fact**
Acetazolamide can cause a rare but serious side effect known as aseptic meningitis, particularly in patients with a history of sulfa allergy. This is a classic exam trap, and students should be aware of the potential risks associated with this medication.
**Correct Answer:** D.