Which of the following is a reference book that provides essential information on medications?

The Physician's Desk Reference (PDR) is a comprehensive resource that offers extensive information on prescription medications, including their uses, dosages, side effects, and contraindications. This reference book serves as a crucial tool for healthcare professionals by providing detailed monographs for a wide variety of drugs, thereby assisting in safe medication administration and patient education.

While the Medical Dictionary is useful for understanding medical terminology, it does not focus specifically on medications. The Diagnostic and Statistical Manual is primarily used for diagnosing mental health disorders and does not provide information on medications. The Medical Terminology Guide offers definitions and classifications of terms but lacks the specific details required to safely understand and manage pharmaceuticals. Hence, the Physician's Desk Reference stands out as the key resource when seeking essential information on medications.