If a patient demands a specific medicine, the physician must inform the insurance company that there are not any other medicines that would be effective for the individual. 4 Select Yes if he wants to apply for continuing coverage. Certain medications need a prior authorization to make sure they are medically necessary and part of a particular treatment program. Many unique drugs may be used to take care of the identical condition. Normally, the pharmacy will speak to the doctor who prescribed the medicine and allow him to know that Joe's medicine demands a PA.. If his medicine wasn't approved, Joe should call his insurance business to learn why.