A drug is a chemical substance used to control a body function or symptom. The words drug, medication, and medicine are interchangeable. All drugs are classified according to how you can obtain them. A prescription drug is a drug that has to be ordered by a physician either in writing or by telephone. Narcotics are just one class of prescription drugs that act on the brain and other parts of the body and can produce a physical addiction if used for long periods of time.
Controlled substances are drugs regulated by the federal or state governments.
Combination drugs are medications that contains two of more separate drugs. While most of these drugs were combined to achieve a better effect on patients, some combination drugs are dangerous or ineffective. That's why many people like to ask their physicians if they're willing to prescribe the generic. At times, your doctor may prefer a specific brand because it's more effective than the generic or has a specific feature such as better taste. Antibiotic is a term used to refer to a group of drugs that destroy bacteria.