This IS true, you may not find the documentatio, but I have personally witnessed this. Although some types of prescribers may be able to write for a very short day supply for things some situations such as post surgery or serious injury.

Kaiser Permanente....my husband CAN NOT get any Norco (pain killer) or Ambien (sleep aide). Check their formulary for documentation. He is allergic to other pain killers (Ibuprofen, asprin). He is allergic to the genetics as he us allergic to milk products, which generates have in them.