I Have Chronic Back Pain And Fibromiga And Unable To

I have chronic back pain and fibromiga and unable to take ISAIDS due to taking warfarin and stage 3 CKF. Insurance to high to afford Lyric so only can take Tynenol. I have taken generic Vicoden in which help a lot.taken prn only and only Rx. a small amount a month. I don't it everyday just when pain to intense after other relief remedies tried. Why cant I receve the Vicodin that I need