This novel study evaluated the effects of vardenafil and sildenafil on QT and corrected QT (QTc) duration using a model that minimizes experimental error to obtain the most accurate assessment of observed QTc effects. A placebo-controlled and positive-controlled, period-balanced, double-blinded, 6-way crossover study evaluated therapeutic and supratherapeutic oral doses of vardenafil (10 and 80 mg, respectively) and sildenafil (50 and 400 mg, respectively), therapeutic doses of moxifloxacin (400 mg), and a placebo in 58 healthy men (mean age 53 years), with dosing every 3 days. Six replicate, 12-lead, digital electrocardiograms (ECGs) were recorded at 3 time points before and 5 time points after dosing to cover the time course of maximum exposure to study drugs and their metabolites.
View Article and Find Full Text PDFContinuous monitoring of the electrocardiogram has become a commonly used technique in the safety assessment of new drugs when these are administered to human beings for the first time. Disturbances of cardiac rhythm have been observed with cardiac monitoring during clinical pharmacology studies in normal healthy volunteers. It is often difficult to assess the clinical significance of these rhythms especially when these rhythms occur following the administration of new drugs to human beings for the first time.
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