My Husband Has Been Given Apo-Prazosin Because He Was Getting

my husband has been given Apo-Prazosin because he was getting up during the night to go to the bathroom his doctor gave him this medication and he now gets up more often. He has mensioned to his doctor and he said it will soon settle down keep taking the tablets. He is also very tired and lacks energy. He is 73 years of age but has always been fit.