October 8, 2009 — 根據一項於9月28日內科醫學誌發表的研究結果，相較於其他降血壓藥物，血管張力素轉化酵素抑制劑（ACEIs）更可能造成高血鉀。然而，非糖尿病與高血壓慢性腎臟疾病（CKD）接受ACEIs類藥物治療患者，風險較低，特別是如果起始與追蹤腎絲球廓清率（GFR）超過40 mlmin/1.73 m2的患者或者是接受利尿劑治療病患。
來自紐約州紐約市Lenox Hill醫院的Joy M. Weinberg醫師，與其來自非裔美人高血壓及腎臟疾病聯合研究團隊的同事們寫到，使用ACEIs類藥物相關的高血鉀經常被報導，且ACEIs類藥物經常因為擔心高血鉀而減少處方。他們使用非裔美人腎臟與高血壓（AASK）資料庫研究接受ACEIs類藥物以及其他降血壓藥物治療之CKD病患發生高血鉀的盛行率與危險因子。
ACEIs More Likely Than Other Antihypertensive Drugs to Cause Hyperkalemia
By Laurie Barclay, MD
Medscape Medical News
October 8, 2009 — Angiotensin-converting enzyme inhibitors (ACEIs) are more likely than other antihypertensive drugs to cause hyperkalemia, according to the results of a study reported in the September 28 issue of the Archives of Internal Medicine. However, the risk for hyperkalemia is small in nondiabetic patients with hypertensive chronic kidney disease (CKD) treated with ACEIs, particularly if baseline and follow-up glomerular filtration rate (GFR) exceed 40 mL/minute/1.73 m2 and if patients receive a diuretic.
"Hyperkalemia from ACEI use has been frequently described, and ACEIs are often underprescribed in patients with CKD because of concerns of hyperkalemia," write Joy M. Weinberg, MD, from Lenox Hill Hospital in New York, NY, and colleagues from the African American Study of Hypertension and Kidney Disease Collaborative Research Group. "The incidence and factors associated with hyperkalemia in patients with...CKD treated with...ACEIs and other antihypertensive drugs was investigated using the African American Study of Kidney Disease and Hypertension (AASK) database."
In the AASK trial, 1094 nondiabetic adults with hypertensive CKD (GFR, 20 - 65 mL/minute/1.73 m2) were observed for 3.0 to 6.4 years and randomly assigned to treatment with an ACEI, beta-blocker, or dihydropyridine calcium channel blocker. For this analysis, the main endpoints were a serum potassium level greater than 5.5 mEq/L (to convert to millimoles per liter, multiply by 1.0), or a clinical center–initiated hyperkalemia stop point.
Among 6497 potassium measurements, 80 hyperkalemic events were identified in 51 participants, including 76 events identified by a central laboratory result and 4 events identified by a clinical center–initiated hyperkalemia stop point.
The hazard ratio (HR) for hyperkalemia in patients with a GFR between 31 and 40 mL/minute/1.73m2 vs a GFR higher than 50 mL/minute/ 1.73 m2 after multivariable adjustment was 3.61 (95% confidence interval [CI], 1.42 - 9.18; P = .007). For a GFR lower than 30 mL/minute/1.73 m2, HR was 6.81 (95% CI, 2.67 - 17.35; P < .001). Risk for hyperkalemia was not increased if GFR was 41 to 50 mL/minute/1.73 m2.
There were more episodes of hyperkalemia with ACEI use vs calcium channel blocker use (HR, 7.00; 95% CI, 2.29 - 21.39; P < .001) or with beta-blocker use (HR, 2.85; 95% CI, 1.50 - 5.42; P = .001). Risk for hyperkalemia was decreased by 59% when diuretics were used.
"In nondiabetic patients with hypertensive CKD treated with ACEIs, the risk of hyperkalemia is small, particularly if baseline and follow-up GFR is higher than 40 mL/min/1.73 m2," the study authors write. "Including a diuretic in the regimen may markedly reduce risk of hyperkalemia."
Limitations of this study include probably insufficient power to detect a difference in the rate of hyperkalemia between dose levels of ACEIs and limited generalizability to other drugs in the classes studied, to ethnic groups other than African Americans, and to a general routine care setting. In addition, the number of hyperkalemic events in the group with a GFR of less than 20 mL/minute/1.73m2 was probably underestimated.
"In the setting of nondiabetic, hypertensive CKD, the risk of hyperkalemia is inversely related to GFR and BMI [body mass index], regardless of antihypertensive treatment," the study authors conclude. "After initiation of antihypertensive therapy, the risk of hyperkalemia is greatest with ACEI use, intermediate with BB [beta-blocker] use, and lowest with CCB [calcium channel blocker] use."
The AASK trial was sponsored by the National Institute of Diabetes and Digestive and Kidney Diseases and received additional financial support from the Office of Research in Minority Health and drug donations from Pfizer Inc, AstraZeneca Pharmaceuticals, and King Pharmaceuticals. The study authors have disclosed no relevant financial relationships.
