A Randomized Comparison of the Effect of Two Diuretics, a Converting Enzyme Inhibitor, and a Sympathomimeticamine on Weight Loss in Diet-Refractory Patients

Abstract

We hypothesized that women refractory to dietary weight loss may have a type of idiopathic edema. In a study of 200 women, we compared four drugs, used previously for treating idiopathic edema, to determine their efficacy in causing weight reduction. After 6 months of treatment, the percentage of treated groups losing at least 10% of baseline weight was 6% for hydrochlorothiazide, 8% for spironolactone, 68% for dextroamphetamine sulfate, and 4% for captopril. The percentage losing >20% and >30% of baseline weight in the same treatment groups was 28% and 10% for dextroamphetamine therapy but 0% for the other three groups. Of the women who failed to lose weight with one of the nonamphetamine therapies during the first 6 months, 132 were then treated with dextroamphetamine; 68% lost =10% of their baseline weight, and 30% and 7% of patients lost =20% and =30%, respectively. With use of the classic definition of idiopathic orthostatic edema (urinary output of <55% of ingested water load in 4 hours), only 58 of the 200 study patients had this diagnosis; however, 144 patients excreted <75% of the load. Comparison of the efficacy of amphetamine therapy in patients with <75% versus =75% urinary excretion showed 120 of 131 (92%) lost =10% in the former category versus only 4 of 51 (8%) in the latter. Of the 58 patients who excreted <55% of the water load, 52 (90%) lost =10% of baseline weight with amphetamine therapy. The patients noted no effects of therapy on dietary consumption. The responsiveness of the patients to amphetamine therapy during the second 6-month period despite failing to lose weight with the three other therapies suggests that no inadvertent bias was present in the randomization process. Thus, the results suggest that some women who are recalcitrant to dietary weight loss may have a mild type of water retention that is refractory to diuretics but responsive to amphetamines.