Preventable sudden death in patients receiving angiotensin converting enzyme inhibitors and loop/potassium sparing diuretic combinations.

Angiotensin-converting-enzyme inhibitors are frequently used in conjunction with diuretics in the treatment of congestive cardiac failure. We report two cases in which use of a proprietary combination diuretic containing a loop diuretic and potassium sparing agent with an angiotensin converting enzyme inhibitor was associated with hyperkalaemic cardiac arrest. Successful resuscitation from the arrest permitted elucidation of its mechanism. We believe that this outcome has not previously been reported, and emphasise the importance of electrolyte monitoring in patients receiving angiotensin converting enzyme inhibitors particularly if prescribed in addition to fixed combination proprietary diuretics.