In order to practice pharmacy in the United States, students must earn a Doctor of Pharmacy (Pharm.D.) degree and pass a state license exam. Pharmacists are licensed to provide information related to medication to patients and other health care professionals. They not only dispense medication, but also monitor patient health and educate patients as to the correct usage of pharmaceutical drugs. They are knowledgeable regarding the composition and properties of drugs and use this knowledge to prevent harmful drug interactions.