Opioids are derived from opium poppies. These include morphine and codeine. Opioids refer to synthetically produced substances that have the same effect as morphine or codeine.

Opiates and opioids include heroin, oxycodone, hydromorphone, meperidine, propoxyphene, and methadone. All of these substances, natural or synthetic, are considered narcotics. Used as pain-killers, these drugs promote sedation, decrease anxiety, and produce a different perception of painful stimuli.

Because heroin is commonly used intravenously (injected into a vein), health concerns related to sharing contaminated needles among IV drug users must be considered. Complications of sharing contaminated needles include hepatitis, HIV infection, and AIDS.