Opiates bind to opioid receptors in the body and reduce the intensity of pain signals, and they fall into four general classes, according to The National Alliance of Advocates for Buprenorphine Treatment:

  • Those that are naturally produced in the body.
  • Opium alkaloids, which are organic compounds and include morphine and codeine.
  • Semi-synthetic opiates, which include heroin and oxycodone.
  • Fully synthetic opiates, which include methadone.

Opiates are prescribed by physicians to treat pain. According to the National Institute on Drug Abuse, the most commonly prescribed opiates are:

  • Hydrocodone (Vicodin), which is typically prescribed for a range of painful conditions, including medical and dental pain.
  • Oxycodone (OxyContin), which is also prescribed for various types of pain but carries different side effects than hydrocodone.
  • Morphine (Avinza), which is prescribed for severe pain, such as that due to surgery.
  • Codeine, which is prescribed for mild pain and is often used to relieve severe diarrhea and coughs as well.

Opiates are considered extremely addictive, which is why prescription opiates appear on Schedule II of the Controlled Substances Act. Schedule II drugs carry a very high risk of developing a dependence on these drugs, but they have some medical value. Heroin, on the other hand, is a Schedule I drug, which means that there’s a high risk of developing a dependence on it, but there is no medical value in using it.