Fosinopril sodium is the first of the phosphinic acid class of angiotensin-
converting enzyme inhibitors (ACEI). It is used as an antihypertensive agen
t, but differs from other ACEI in its dual routes of excretion (liver and k
idney), and less incidence of hyperkalemia and cough. We conducted a study
in known chronic hemodialysis patients who developed interdialytic hyperkal
emia in spite of other treatments to control hyperkalemia. We used fosinopr
il in this group of patients to assess the effect of fosinopril on serum po
tassium (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 dialys
is treatment. Interdialytic weight gains were recorded. The average pretria
l potassium level was 6.57 mmol/l (+/- 0.47), and the posttrial level was 5
.34 (+/- 0.76); p less than or equal to 0.0001. No statistically significan
t interdialytic weight gain or reduction occurred. No first dose hypertensi
ve 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.