Cakir Mehtap
Division of Endocrinology and Metabolism, Meram School of Medicine, Selcuk University, Konya, Turkey.
Blood Press. 2010 Dec;19(6):380-2. doi: 10.3109/08037051.2010.488056. Epub 2010 May 21.
The renin-angiotensin-aldosterone system (RAAS) has crucial importance in maintaining blood pressure; thus blockade of RAAS is an effective antihypertensive treatment choice. The final step in RAAS stimulation is aldosterone secretion by angiotensin II, which leads to increased renal tubular sodium absorption and potassium secretion. Angiotensin II receptor blockers (ARBs) allow blockade of RAAS by blocking binding of angiotensin II to the AT(1) receptors. There are several fixed-dose combinations of ARBs with hydrochlorothiazide in the market, providing antihypertensive therapies with complimentary mechanisms of action. With such combinations, while ARB inhibits the vasoconstricting action and aldosterone-secreting effects of angiotensin II, hydrochlorothiazide affects the renal tubular mechanisms of electrolyte reabsorption and directly increases excretion of sodium and chloride in the distal tubule, and promotes water excretion. Also, hypokalemia, which may be triggered by increased urinary potassium loss induced by hydrochlorothiazide, is opposed by ARB use and hence ARB/hydrochlorothiazide combination is known to be safe in terms of potassium imbalance. In this case report, significant hyperkalemia and hyponatremia related to telmisartan/hydrochlorothiazide use in a diabetic patient has been presented.
肾素-血管紧张素-醛固酮系统（RAAS）在维持血压方面至关重要；因此，阻断RAAS是一种有效的抗高血压治疗选择。RAAS激活的最后一步是血管紧张素II分泌醛固酮，这会导致肾小管钠重吸收增加和钾分泌增加。血管紧张素II受体阻滞剂（ARB）通过阻断血管紧张素II与AT(1)受体的结合来阻断RAAS。市场上有几种ARB与氢氯噻嗪的固定剂量组合，提供具有互补作用机制的抗高血压治疗。通过这种组合，ARB抑制血管紧张素II的血管收缩作用和醛固酮分泌作用，而氢氯噻嗪影响肾小管电解质重吸收机制，并直接增加远端小管中钠和氯的排泄，促进水排泄。此外，氢氯噻嗪引起的尿钾丢失增加可能引发的低钾血症，会因使用ARB而得到缓解，因此ARB/氢氯噻嗪组合在钾失衡方面被认为是安全的。在本病例报告中，呈现了一名糖尿病患者使用替米沙坦/氢氯噻嗪后出现显著高钾血症和低钠血症的情况。
