Abstract: AIM: To observe the effects of angiotensin receptor antagonistlosartan and angiotensin converting enzyme inhibitor captopril on serum digoxin concentrations and clinical efficacy in thePatients with heart failure.METHODS: Twenty-eightPatients with NYHA classⅡ-Ⅳ heart failure were randomly assigned tolosartan grouPand captopril group,were treated with digoxin 0.25 mg(Po,qd)for 1 wk.And then followed by 4wk combination withlosartan(50 mg,po,qd)or captopril(25 mg,po,tid).The serum digoxin concentrations and clinical features were monitored and measured.RESULTS: Losartan did not increase the steady statelevel of serum digoxin,but captopril could increase serum digoxin concentrations by 29.6%;both groups had the effects of increasinglVEF,reducing heart rate,decreasing bloodPressure,the total clinical effective rates oflosartan grouPand captopril grouPwere 92.9% and 85.7%,respectively.The serumPotassium and creatinine were unchanged.The compliance inlosartan grouPwas better than that in captopril group.CONCLUSION: Bothlosartan and captopril were effective in treatment ofPatients with heart failure.The co-administration of digoxin withlosartan was safe.The digoxin concentrations should be monitored in combination with captopril.

Key words: pharmacodynamics, losartan, captopril, digoxin, serum concentration, heart failure