Purpose: The effect of Metabolife Ephedra-Free on blood pressure (BP) and hemodynamics was studied.
Methods: Healthy volunteers were randomly assigned to take a single dose of Metabolife Ephedra-Free or matching placebo and then crossed over to the opposite treatment after a seven-day washout period. BP was measured at baseline and one, three, and five hours after administration. Cardiac index, systemic vascular resistance index (SVRI), and total thoracic fluid content were determined in a subgroup of subjects.
Results: Twenty patients (mean +/- S.D. age, 24.8 +/- 1.9 years) completed the study. No significant differences in systolic or diastolic BP were found between the Metabolife Ephedra-Free and placebo groups. In the subgroup (n = 8), SVRI was higher (but not significantly so) in the Metabolife Ephedra-Free group than in the placebo group at one hour (2162.5 +/- 421.1 versus 1934.6 +/- 344.2 dyn x sec x cm(-5) x m(2)); the difference was significant at five hours (1981.6 +/- 293.3 versus 1765.1 +/- 340.3 dyn x sec x cm(-5) x m(2)).
Conclusion: Single doses of Metabolife Ephedra-Free did not affect BP in healthy young volunteers. SVRI did not exceed the normal range but was elevated at five hours compared with SVRI in placebo recipients.