I would also like the treatment of pain in patients with sickle cell disease to be an exception.  Many of these patients live with chronic pain with acute exacerbations they can manage at home.  Limitations on dosing would hinder their ability to do this and would send them to the ED, which typically would be either unnecessary or an overtreatment of something they could have handled at home.  Even managing children with sickle cell disease with these limitations is challenging.  I also think it is very important that patients with chronic pain know they have medicine when needed.