The Physicians' Desk Reference (PDR) is often legally held to be the "Bible" for the standard of medical usage of pharmaceutical drugs. However, the PDR is merely a collection of the various package inserts of most of the available medications and a picture of the stated drug. It is provided free to physicians and is sold for profit to various entities, including the general public at bookstores. Thus, all of its information regarding the highlighted drugs is provided by the respective pharmaceutical companies.
Burkhart CG, Burkhart KM, Burkhart AK. The Physicians' Desk Reference Should Not Be Held as a Legal Standard of Medical Care. Arch Pediatr Adolesc Med. 1998;152(6):609-610. doi: