Does Long-Term Furosemide Therapy Cause Thiamine Deficiency in Patients with Heart Failure? A Focused Review

Abstract Diuretic therapy is a cornerstone in the management of heart failure. Most studies assessing body thiamine status have reported variable degrees of thiamine deficiency in patients with heart failure, particularly those treated chronically with high doses of furosemide. Thiamine deficiency in heart failure patients appears to be predominantly attributable to increased urine volume and urinary flow rate. There is also evidence that furosemide may directly inhibit thiamine uptake at the cellular level. Limited data suggest that thiamine supplementation is capable of increasing left ventricular ejection fraction and improving functional capacity in patients with heart failure and a reduced left ventricular ejection fraction who were treated with diuretics (predominantly furosemide). It may therefore be reasonable to provide such patients with thiamine supplementation during heart failure exacerbations.