Pharmacological and clinical studies of ephedrine and other thermogenic agonists

When given as a supplement to an energy restricted diet the sympathomimetic agent ephedrine, in combination with methylxanthines such as caffeine, improves fat loss by dual actions: a central suppression of appetite and peripheral stimulation of energy expenditure covered by fat oxidation. Mean weight loss was found to be 16.6 kg after 6 months when E+C was given as an adjuvant to an efficient hypoenergetic diet, which was 3.4 kg higher than in the placebo group. An additional 24 weeks treatment with E+C prevented relapse. In the first weeks of treatment E+C offset the hypotensive effect of energy restriction and weight loss, but the effect was transient, and after 8 weeks blood pressures were indistinguishable from those of the placebo group. E+C has no adverse effect on glucose and lipid metabolism, but has been shown to prevent the decline in HDL-cholesterol caused by weight loss. In a comparative trial the weight loss produced by E+C was similar to that of dexfenfluramine. More research on sympathomimetics and methylxanthines should be carried out to identify combinations with improved efficiency and safety. Moreover, more long-term trials and studies in males are required.