Narcotic drugs are drugs that act like morphine.
They act by stimulating receptors on cells in the brain that are called opioid receptors. The primary medical use of these drugs is to reduce pain. Commonly used narcotics include heroin, morphine, codeine, and methadone. When taken over time to reduce pain or for the pleasant, drowsy, floating feeling they give, narcotics may make you dependent or addicted. Also, if you take these drugs repeatedly you may develop a tolerance to them.