A New Treatment forInterdialytic Hyperkalemia – The Use of Fosinopril Sodium

Abstract

Fosinopril sodium is the first of the phosphinic acid class of angiotensin-converting enzyme inhibitors (ACEI). It is used as an antihypertensive agent, but differs from other ACEI in its dual routes of excretion (liver and kidney), and less incidence of hyperkalemia and cough. We conducted a study in known chronic hemodialysis patients who developed interdialytic hyperkalemia in spite of other treatments to control hyperkalemia. We used fosinopril in this group of patients to assess the effect of fosinopril on serum potassium (K) levels. Twenty-four patients were given fosinopril 10 mg at 18:00 h daily for 8 weeks. K levels were measured before and after each dialysis treatment. Interdialytic weight gains were recorded. The average pretrial potassium level was 6.57 mmol/l (± 0.47), and the posttrial level was 5.34 (± 0.76); p ≤ 0.0001. No statistically significant interdialytic weight gain or reduction occurred. No first dose hypertensive effect or cough were reported. We have found the use of fosinopril to be successful in lowering predialysis serum K levels in hyperkalemic dialysis patients.

Hyperkalemia in Dialysis Patients

“…To the extent that aldosterone may enhance extrarenal potassium disposal, hemodialysis circuit anticoagulation with low molecular weight heparin (which suppresses angiotensin‐mediated aldosterone biosynthesis less than unfractionated heparin) may be of some small benefit in reducing predialysis S K (120). At present, there is no evidence to support the use of exogenous mineralocorticoids to improve long‐term potassium tolerance in ESRD patients (15,52).…”

Management of Hyperkalemia in Dialysis Patients

“…Surprisingly, the authors found a statistically significant drop in average predialysis potassium levels from 6.7 to 5.5 m m after 4 weeks of drug therapy. The predialysis serum potassium decreased in 20 of 23 patients treated with fosinopril, and subsequently increased after the drug was discontinued (70). It is possible that fosinopril enhances potassium secretion through the biliary system, thereby decreasing the interdialytic serum‐potassium levels.…”

Klinische Aspekte der Hyperkaliämie

“…Es gibt Studien, die möglicherweise darauf hindeuten, dass bei Patienten mit einer eingeschränkten Nierenfunktion unter einer Therapie mit Fosinopril weniger Hyperkaliämien auftreten als unter anderen ACE-Hemmern[15,16]. Der M. Addison führt zu verminderter Aldosteronsynthese per se.…”