Prescription drugs require a prescription from a medical practitioner and can only be obtained from a pharmacy. They have many applications, including treating pain, anxiety, and hypertension.

The misuse and addiction to prescription drugs is a growing problem that can affect people of all age groups, specifically teenagers. This can happen when prescription medications are used in ways not intended by the prescriber, such as taking someone else's prescription or using medication for intoxication. Opioid painkillers, anti-anxiety medicines, sedatives, and stimulants are among the most commonly misused prescription drugs. Symptoms of prescription drug abuse vary depending on the drug. Identifying and intervening early in cases of prescription drug abuse can help prevent the problem from escalating into addiction.

On the other hand, nonprescription drugs, also known as over-the-counter (OTC) drugs, can be obtained without a prescription. Examples of common nonprescription drugs include ibuprofen, omeprazole, loratadine, and nicotine patches. There is also potential for abuse of these types of medications, such as pseudoephedrine and dextromethorphan, that have brought cause for age and purchase amount restrictions. However, these drugs are generally considered safe for use without medical supervision.

Orphan drugs are a special category of drugs used to diagnose or treat rare diseases that affect a small number of individuals, typically less than 200,000. Examples of these rare diseases include cystic fibrosis, pulmonary hypertension, and Duncan's syndrome. They are often challenging to research, develop, and market due to the complex process of establishing their safety and efficacy in the small patient population, lack of funding, and the high development cost. Governments and nonprofit organizations provide incentives and funding to pharmaceutical companies to encourage the development of orphan drugs.

Since the Orphan Drug Amendment of 1983, the FDA has approved over 300 orphan drugs for marketing, targeting more than 82 rare diseases.