What Kind of Drug Is It?

Codeine is an opiate analgesic, meaning it is a pain reliever derived from the opium poppy plant. Its powers of pain relief—and its side effects—are many times weaker than the related opiates MORPHINE and heroin. (An entry for each of these drugs is available in this encyclopedia.)

Doctors sometimes prescribe pills containing combinations of codeine and over-the-counter (OTC) analgesics, such as Tylenol (acetaminophen) or aspirin, for pain relief after minor surgery, or for bone breaks and sprains, migraine headaches, or other pain that is expected to pass fairly quickly. The other most common use for codeine is in cough syrup. The drug acts on the part of the brain that controls coughing.

In the United States and many other countries, a prescription is necessary to obtain products containing codeine. This is because the drug is addictive, or habit-forming. It also...