Xipamide

Xipamide is an orally active carbonic anhydrase (CA) inhibitor and Na⁺/Cl^--potassium transporter inhibitor with diuretic and antihypertensive effects. Xipamide reduces NaCl reabsorption by inhibiting the Cl^-/NaCO₃^- anion exchanger, and increases calcium reabsorption while promoting potassium and magnesium excretion. Xipamide is mainly cleared via the renal pathway and causes a temporary decrease in glomerular filtration rate under specific conditions. Xipamide does not affect Ca²⁺ signaling induced by endothelin-1 and other factors, nor does it inhibit various ion cotransport or pump activities in red blood cells. Xipamide can be used in researches related to cardiovascular diseases, hypertension (especially with left ventricular hypertrophy), advanced renal failure, and liver cirrhosis with ascites^[1][2][3]. In Vitro:Xipamide (0.1-100 μM; 3-15 min) maximally inhibits amiloride-induced cell acidification by 50% at 1 μM (after 15 min preincubation) in rat heart myogenic H9c2 cells, an effect that is dependent on extracellular HCO₃⁻ and sensitive to DIDS^[2].
Xipamide (10^-5-10^-3 M; 90 min) potently inhibits the (NaCO₃⁻/Cl⁻) anion exchanger in fresh human red blood cells with an IC₅₀ of 2.5 × 10^-5 M, making it the most active anion carrier inhibitor among the tested diuretics^[3].