Why loop diuretics is not effective in some patients, even they don have hyperaldosteronism?
This is a difficult subject for third year students. However, here are some advices for management of Refractory edema 1. Diuretics have a dose-response curve, with no natriuresis seen until a threshold rate of drug excretion is attained. A patient who does not respond to 40 mg of furosemide may not be exceeding this threshold. Thus, the single dose should be increased to 60-80 mg rather than giving the same dose twice a day. 2. Maintenance of sodium intake can prevent net fluid loss even though an adequate diuresis is being achieved. Sodium excretion in 24 hour urine above 100 meq indicates an adequate diuretic response and sodium restriction is advised. 3. Unstable heart failure or advanced cirrhosis may require initial intravenous therapy, since decreased intestinal perfusion, reduced intestinal motility, & perhaps mucosal edema may substantially slow the rate of diuretics absorption. 4. Oral bumetanide or torsemide are much more completely absorbed while only about 50% of oral furo
