Acetazolamide and Hypokalemia? Why? - koobcam - Printable Version +- USMLE Forum - Largest USMLE Community (https://www.usmleforum.com) +-- Forum: USMLE Forum (https://www.usmleforum.com/forumdisplay.php?fid=1) +--- Forum: Step 1 (https://www.usmleforum.com/forumdisplay.php?fid=2) +--- Thread: Acetazolamide and Hypokalemia? Why? - koobcam (/showthread.php?tid=561611) |
Acetazolamide and Hypokalemia? Why? - koobcam - ArchivalUser - 01-12-2011 Im having trouble understanding Acetazolamide I know it blocks Carbonic Anhydrase Resulting in: Increased Na Loss in urine Increased HCO3 Loss in urine Why is there a hypokalemia? 0 - ArchivalUser - 01-12-2011 Whenever you have increased urine output, it's like flushing the nephrons with water and thus K would be flushed as well. So K is lost in the urine. But remember you're losing HCO3 from the serum ==> acidemia ==> hyperkalemia as it's being shifted from inside the cells into the serum. In general, the total body K is less, but the serum K could be normal or elevated. 0 - ArchivalUser - 01-12-2011 I understand this, yet the literature always mentions a side effect as being Hypokalemia, and not Hyperkalemia... that's where im a little confused. 0 - ArchivalUser - 01-12-2011 MOST OF SODIUM EXCRETED IN PROX. TUBULE (LARGE CONC.)SHOULD BE REABSORB. IN DISTAL TUBUL,,,,THIS WILL BE IN EXCHANGE OF POTASIUM,,,, LEAD TO HYPOKALEMA,,,,,,BEST REGARDS 0 - ArchivalUser - 01-12-2011 look that's how I understand this, acetazolamide increases HCO3 excretion. your body get it as an approaching acidosis, so the kidney start increase H reabsorption which happens in exchange with K, who(;ie k) goes down in the toilet. hope its easier now 0 - ArchivalUser - 08-10-2021 Due to CA enzyme inhibition H+ is not buffered by Hco3- in PCT lumen and neither of them are generated inside the PCT cells. Upon reaching the collecting duct, due to increased load of H + in tubular lumen H+/K+ antiport is less functional. So there is reduced K+ absorption and therfore hypokalemia 0 - ArchivalUser - 08-24-2021 acetazolamide increases HCO3 excretion. your body get it as an approaching acidosis, so the kidney start increase H reabsorption which happens in exchange with K, |