Previous studies suggest that
adenosine A₁ receptor antagonists may promote natriuresis without deleterious effects on renal function. This study evaluated renal and hemodynamic effects as well as safety, pharmacokinetics, and tolerability of
BG9928, a selective
adenosine A₁-receptor antagonist, in patients with
heart failure. In this multicenter, randomized, double-blind, placebo-controlled, dose-escalation study, 33 patients received a single dose of
BG9928 (0.03, 0.3, 1.0, or 3.0 mg/kg) or placebo intravenously. Change from baseline in urinary
sodium excretion for the 8-hour postdose interval was greater for all dosing groups versus placebo. The 0.03-mg/kg and 0.3-mg/kg groups had significant reductions in
body weight versus placebo (-0.8 kg, -1.1 kg, 0.3 kg, respectively; P < 005). No changes in
creatinine clearance or hemodynamic parameters were observed among any of the
BG9928 groups versus placebo. However, pulmonary capillary wedge pressure tended to decrease and correlated with
weight loss. Across the range of doses studied, pharmacokinetic parameters were linear and predictable. One patient who received the highest dose (3.0 mg/kg) developed
seizures, and no further patients received that dose. Single intravenous
BG9928 doses of up to 1.0 mg/kg were well tolerated and increased
sodium excretion without worsening renal function. Further studies are needed to determine the clinical benefit of
adenosine A₁ receptor antagonism.