Topiramate is known to cause what type of metabolic acidosis?

Topiramate is known to cause a specific type of metabolic acidosis called hyperchloremic metabolic acidosis, which is characterized by a normal anion gap. This occurs primarily due to increased bicarbonate (HCO3) excretion in the kidneys, leading to a relative increase in chloride concentrations.

The mechanism involves topiramate's effect on carbonic anhydrase, which can inhibit the enzyme and cause decreased bicarbonate reabsorption in the proximal renal tubule. As bicarbonate levels drop, there is a compensatory rise in serum chloride, resulting in hyperchloremic metabolic acidosis. This type of metabolic acidosis is often seen in clinical practice with prolonged use of topiramate, especially in patients who are also using carbonic anhydrase inhibitors or have concurrent conditions that may influence bicarbonate balance.

Understanding this mechanism is essential for healthcare professionals managing patients on topiramate, as they should monitor for potential changes in acid-base status and adjust treatment accordingly to prevent complications associated with metabolic acidosis.