Tonapofylline (KW-3902) is a selective adenosine A1 receptor antagonist primarily developed for the treatment of acute decompensated heart failure (ADHF), particularly in patients with renal impairment. It helps alleviate fluid overload and congestion while providing renal protection by counteracting the vasoconstrictive effects of adenosine on the kidneys, thereby improving glomerular filtration rate and reducing the risk of acute kidney injury (AKI). It has shown promise in preventing contrast-induced nephropathy in high-risk patients undergoing imaging procedures with iodinated contrast media. Additionally, it has been investigated for renal protection in cardiac surgery settings, demonstrating potential to decrease the need for dialysis and improve overall outcomes. Unlike traditional diuretics, tonapofylline promotes diuresis without causing significant electrolyte imbalances or further renal stress, positioning it as a novel therapeutic agent for cardiorenal syndromes.