Hi, I am a 64 year old male.I am 5.10 tall and I weight 198 lb.I often exercise at gym more than an hour at the time.. I believe , I am an healthy person. I am currently under medication: I take Tamsulosin .4mg , Atorvastatin 20 mg.,Lisinopril 5 mg. ,Levitra 20 mg. and vitamins such a Fish oil ,B complex.I do drink an average of 3 glasses of homemade red wine at dinner .I am being taking Levitra for about six years whit great result , lately levitra is not working at all .It is because I am getting older? It is due to a prostate dysfunction?.Advise me please.