版主你好Thiazides 主要作用於腎元遠端小管，藉由抑制Na+/Cl- co-transporter 而減少Na+和Cl-的再吸收，同時導致K+排出，阻礙尿液濃縮機制，造成尿液排除增加。有幾種機制，Thiazides引起低血鉀（血清鉀濃度下降）： Increased delivery of sodium to the collecting ducts causes increased cellular uptake of Na from the lumen by apical Epithelial Na Channels (ENaCs).交付增加鈉的原因增加集合管細胞攝取的鈉從管腔上皮鈉通道的頂（ENaCs）。 This then causes the basolateral Na/K exchanger to more actively exchange Na for K, which is then passively secreted into the lumen through apical channels, resulting in K loss.這進而導致基底鈉 / K的交換，更加積極地交換鈉為 K，這是被動的分泌到管腔通過根尖渠道，在K造成的損失。 (Moreover, the increased delivery of K to the collecting ducts facilitates the exchange of K for H by the H/K exchangers on the intercalated alpha cells, resulting in loss of H [metabolic alkalosis].) （此外，增加K到交付的交流有利於集合管的K為 H由H / K的交換機上插α細胞，造成損失的H [代謝性鹼中毒]。） Activation of renin-angiotensin-aldosterone system by the diuretic hypovolemia: body responds to hypovolemia by opposing diuresis, one effect of which is to produce aldosterone which stimulates the Na/K exchanger, resulting in further loss of potassium.激活腎素血管緊張素醛固酮系統的利尿低血容量：身體對低血容量利尿的反對，其中一個效果是產生醛酮固能刺激鈉/ K的交換，從而導致進一步損失鉀。 For this reason, ACE inhibitors , which inhibit angiotensin II production and therefore aldosterone activation, are frequently used in combination with thiazides to combat hypokalemia. Flow rate in nephron is increased under diuresis, reducing potassium concentration in the lumen, thus increasing the potassium gradient.流率下，增加腎利尿，鉀濃度減少，管腔，從而增加了鉀梯度。 Potassium loss through the many potassium channels, such as ROMK.鉀流失的渠道很多，如ROMK。 These are not exchangers; they allow facilitated diffusion, so the increased gradient is directly responsible for increased diffusion.這些都不是交換，他們讓利於擴散，因此，增加直接負責的梯度增加擴散。 資料來源http://140.116.253.135/NewHomePage/manager/form/pe...
· 2011-05-29
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當飲食中攝取過多的鈉離子，使腎臟必需排出更多的鈉，進而產生更高的促鉀離子排出的電化學梯度，造成大量鉀流失。 利尿劑最常見的副作用為低血鉀症。當血鉀為3.5mEq/L時就屬於輕度血鉀過低，若低於2.5 -3m Eq/L為中低血鉀、低於2.5mEq/L即為嚴重低血鉀。臨床上， 輕度低血鉀並沒有明顯症狀，中度低血鉀就會出現抽筋、虛弱、肌肉疼動的症狀。而嚴重低血鉀則會出現低血壓、心電圖改變、心律不整，甚至有致命的可能。因此，使用利尿劑的患者還是需要調整飲食，限制鈉的攝取量以避免低血鉀的發生。 資料來源：thejournal of Taiwan pharmacy 臨床藥學 第25卷 第四期 應用藥理學 徐雅博編著