The air-dried exudate from the unripe seed capsule of the opium poppy, Papaver somniferum, or its variant, P. album. It contains a number of alkaloids, but only a few - MORPHINE; CODEINE; and PAPAVERINE - have clinical significance. Opium has been used as an analgesic, antitussive, antidiarrheal, and antispasmodic.
A drug that is derived from opium, which contains from 0.3-1.5% thebaine depending on its origin. It produces strychnine-like convulsions rather than narcosis. It may be habit-forming and is a controlled substance (opiate) listed in the U.S. Code of Federal Regulations, Title 21 Part 1308.12 (1985). (From Merck Index, 11th ed)