Adams, Raymond D. Harvard Medical School, Boston, Massachusetts.
Last reviewed:April 2019
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Any drug naturally derived from opium, the dried juice of opium poppy (Papaver somniferum) seed pods. In its raw state, opium is an opaque, milky sap that concentrates its active ingredients in the pod (capsule). The pharmacologically active substances, which constitute approximately 25% of the extract, are the alkaloids known as morphine, codeine, and papaverine. (Note that heroin is a compound synthesized from morphine.) Synthetic and semisynthetic compounds, such as fentanyl and oxycodone, which resemble morphine in their action, are called opioids. See also: Fentanyl is the leading cause of drug overdose deaths; Heroin: an addictive drug; Pharmacology; Poppy
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