The "Physician's Desk Reference," or PDR, is a medical compilation containing an index of prescription medications available in the United States, notes Medicine.Net. Aside from the printed material that is published annually, the PDR is also available in electronic book and mobile format.
The PDR is considered to be the most widely used drug reference, according to MedicineNet. However, it mainly contains drug information from trademarked brands as manufacturers have to pay for their products to be included in the PDR.
A Web-based version of the PDR is available at PDR.net. Users can browse for drug information by keying in the name of the drug in the search box provided on the website. A free e-book PDR is also available and users can also download the mobile version to their Apple, Android or Blackberry devices.