Effects of angiotensin II receptor blockers on serum potassium level and hyperkalemia risk: retrospective single-centre analysis.

OBJECTIVE

To examine the effect of angiotensin II receptor blocker (ARB) treatment on serum potassium level and hyperkalaemia risk in a clinical setting with inpatients and outpatients using calcium channel blockers (CCBs) as a reference standard.

METHODS

The increased risk of hyperkalaemia associated with ARB treatment is known, however only a few studies have used an active comparator to examine this risk. In this retrospective study at a 320-bed general hospital in Japan, the hospital information system was used to identify patients with at least one prescription for an ARB (819 patients) or a CCB (1015 patients) who were naive to these drugs before study initiation. Serum potassium levels before and after ARB treatment were compared. Additionally, the unadjusted and adjusted hazard ratios for the risk of hyperkalaemia in the ARB and CCB users were estimated.

RESULTS

The serum potassium level was higher in patients receiving ARB treatment (0.05 mEq/L, p=0.02) compared with those on CCB treatment. However, there was no significant association between ARB use and hyperkalaemia (adjusted HR 0.91, 95% CI 0.42 to 1.99, p=0.82).

CONCLUSION

The increase in serum potassium level after ARB initiation makes it necessary to monitor serum potassium levels continuously during ARB treatment; however, the risk of hyperkalaemia appeared to be similar for ARB and CCB treatments.