Prescription drug abuse (PDA) occurs when an individual (health professionals inclusive) uses a prescribed drug for non-medical purposes, use more than the prescribed dose or continue using it even after the amount prescribed by the physician was taken. Self-medication, on the other hand is the selection and use of drugs to relieve symptoms of a condition without a prescription.

Pain-relieving drugs misuse could be defined as the use of medications for non-medical reasons such as euphoria feeling. Serious adverse health effects result from the abuse of prescription drugs. Narcotics are natural opioids (pain-relieving) drugs that helps to reduce pain and anxiety, promotes drowsiness, induce anaesthesia prior to a surgery. These drugs are commonly prescribed to help individuals with chronic pain lead productive lives.