Metabolic effects of fluoxetine in obese menopausal women

Our objective was to assess thermogenic action of fluoxetine (FL) in obese menopausal women, evaluating the effect of FL administration on resting ene rgy expenditure (REE) and on glucose-induced thermogenesis both after acute administration (40 mg in single dose the evening before measurements) and after a 12- week period of diet treatment plus FL (60 mg per day) or placeb o. It was a double-blind, placebo-controlled design both in acute and in ch ronic study. The subjects were 32 obese, otherwise healthy, menopausal wome n. The patients were assigned randomly to three groups, one performing an a cute study protocol, in which resting and glucose-induced thermogenesis was measured after FL and placebo administration, performed in randomised orde r. The other two groups underwent dietary plus pharmacological treatment (F L or placebo, FL). Resting and glucose-induced thermogenesis was measured a t baseline and after 12 weeks of treatment. The results showed that acute F L administration caused an increase in resting energy expenditure (PL: 5.35 +/-0.18 vs FL: 5.53+/-0.24 KJ/min, p<0.05). A significant decrease of REE w as observed in the PL group after 12 weeks (p<0.03), while a slight, but no t significant, decrease was observed in the FL group (p=NS). FL did not aff ect thermic response to oral glucose neither after acute nor chronic admini stration (p=NS for all groups studied). The conclusion was that our data gi ve support to thermogenic actions of FL after acute administration, suggest ing also that chronic FL treatment may restrain to some degree the metaboli c adaptation expected during weight loss in obese subjects. At variance wit h what observed with other drugs, such as dexfenfluramine, an increased the rmic effect of oral glucose does not seem to be involved in the thermogenet ic action of FL. (C) 2000, Editrice Kurtis.