Which term refers to non-prescribed drugs such as cocaine and heroin?

The correct term that refers to non-prescribed drugs such as cocaine and heroin is "illicit drugs." Illicit drugs are substances that are illegal to use, possess, or distribute. These drugs often have no accepted medical use and pose significant health risks. Cocaine and heroin, specifically, are classified as illicit due to their potential for abuse and harmful effects on both individuals and society.

In contrast, prescription drugs are medications that require a doctor's approval and can only be obtained through a valid prescription. Over-the-counter medications are drugs that can be purchased without a prescription and are considered safe for general use when used as directed. Essential medications typically refer to drugs that meet a high priority in healthcare needs and are deemed necessary for a basic health care system. These distinctions highlight the specific legal and medical frameworks surrounding various categories of drugs, emphasizing the importance of understanding what constitutes illicit substances.