Which of the following is a naturally occurring opiate?

• A. Morphine
• B. Heroin
• C. Methadone
• D. Fentanyl

Answer: (A)

Opiates that occur naturally are alkaloids derived from the opium poppy. Morphine, the principal naturally occurring opiate, is found in opium and used clinically for pain relief. Heroin is made from morphine by acetylation, so it is not naturally occurring; methadone and fentanyl are fully synthetic opioids designed in laboratories. Thus morphine is the naturally occurring opiate.