How are the captopril and losartan suppression tests used in the workup of primary aldosteronism?

Updated: Mar 24, 2020
  • Author: Gabriel I Uwaifo, MD; Chief Editor: Romesh Khardori, MD, PhD, FACP  more...
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Captopril and losartan suppression tests

This involves the oral administration of a single dose of captopril (25-50 mg), an ACE inhibitor. In healthy individuals, aldosterone levels will be suppressed to less than 15 ng/dL. The test has a sensitivity of 90-100% but a specificity of only 50-80%.

In a study of 135 patients who underwent captopril and losartan (an angiotensin-II receptor blocker [ARB]) tests, Wu et al concluded that the values for the PRA ratio and aldosterone concentration derived using the losartan test were more accurate than those obtained through the captopril test for the diagnosis of primary aldosteronism. [27]

The authors found that when a PRA ratio (ng/dL per ng/mL/h) of greater than 35 and an aldosterone concentration of more than 10 ng/dL were used, the diagnostic specificity values for captopril and losartan were 89.1% and 93.8%, respectively, and the respective diagnostic sensitivity values were 66.2% and 84.5%. The authors recommend the preferential performance of the losartan suppression test.

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