interaction between alfuzosin and hydrochlorothiazide in the 8 patients in this study. Electrophysiology . The effect of 10 mg and 40 mg alfuzosin on QT interval was evaluated in a double-blind, randomized, placebo and active-controlled (moxifloxacin 400 mg), 4-way crossover single dose study in 45 healthy white male subjects aged 19 to 45 years..