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Previous studies have demonstrated that intravenous testosterone can dilate coronary arteries and increase exercise treadmill time, but the electrocardiographic and hemodynamic effects are unknown. This trial determined the hemodynamic and electrocardiographic effects of dosing intravenous testosterone to achieve a physiologic and a superphysiologic serum testosterone concentration. Twenty men (70.6 +/- 6.2 years) had individualized testosterone bolus and continuous infusions designed to increase the serum testosterone concentration by two (physiologic) and six times baseline (superphysiologic). The men were studied on three occasions when they were randomly allocated to received a placebo, physiologic testosterone regimen, or superphysiologic testosterone regimen. Blood pressures and 12-lead electrocardiograms (ECGs) were taken preinfusion and 28 minutes after initiating the infusion on each visit. The blood pressure (systolic and diastolic) and ECG variables (PR, QRS, QT, QTc, and RR intervals) preinfusion and during the infusion were compared, and the delta changes in the variables were compared between groups. The physiologic testosterone regimen increased the serum testosterone concentration by 2.39 +/- 0.48 times the preinfusion concentration, while the superphysiologic regimen increased it by 6.22 +/- 0.99 times. No significant changes occurred in the blood pressure or ECG variables in any group versus preinfusion values or between the three groups. Exogenously administered intravenous testosterone does not significantly affect the blood pressure or ECG variables when given to achieve physiologic or superphysiologic concentrations.

Intracoronary testosterone injections have recently been shown to possess coronary vasodilating effects. The same may be true for intravenous testosterone, but the pharmacokinetic and hemodynamic aspects need exploration before pharmacologic studies can begin. This trial determined the pharmacokinetic and hemodynamic properties of 300 microg of testosterone given intravenously. Degree of testosterone aromatization to 17-beta estradiol after exogenous administration and overall patient tolerability also were evaluated. Eleven elderly men with coronary artery disease participated in the study and were given 300 microg of testosterone intravenously over 10 minutes. Serum blood concentrations of testosterone and 17-beta estradiol were measured at baseline and then periodically. Testosterone serum concentrations were stripped and fit to a two-compartment model for all patients. The volume of distribution (Vdarea) was 80.36 +/- 24.51 L, and the elimination half-life was 55.93 +/- 23.06 minutes. No hemodynamic differences or side effects were noted. The serum concentrations of 17-beta estradiol were significantly increased from baseline beginning 5 minutes after infusion to the end of the study (180 minutes after infusion).