The effect of pharmacokinetically guided acute intravenous testosterone administration on electrocardiographic and blood pressure variables

Previous studies have demonstrated that intravenous testosterone can dilate coronary arteries and increase exercise treadmill time, but the electrocar diographic and hemodynamic effects are unknown. This trial determined the h emodynamic and electrocardiographic effects of dosing intravenous testoster one to achieve a physiologic and a superphysiologic serum testosterone conc entration. 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 allocate d to received a placebo, physiologic testosterone regimen, or superphysiolo gic testosterone regimen. Blood pressures and 12-lead electrocardiograms (E CGs) 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 we re compared, and the delta changes in the variables were compared between g roups. The physiologic testosterone regimen increased the serum testosteron e concentration by 2.39 +/- 0.48 times the preinfusion concentration, while the superphysiologic regimen increased it by 6.22 +/- 0.99 times. No signi ficant changes occurred in the blood pressure or BCG variables in any group versus preinfusion values or between the three groups. Exogenously adminis tered intravenous testosterone does not significantly affect the blood pres sure or ECG variables when given to achieve physiologic or superphysiologic concentrations. Journal of Clinical Pharmacology, 1999;39:1038-1043 (C)199 9 the American College of Clinical Pharmacology.