MEDICAL ANIMATION TRANSCRIPT: Opioids are drugs that are prescribed to treat moderately severe or severe pain. Examples of these drugs include hydrocodone, oxycodone, morphine, hydromorphone, methadone, and fentanyl. Heroin, an illegal drug, is also an opioid. In order to understand how opioids work, it's important to know how your body feels pain. The process begins when something harmful happens to your body. Information about this harm is converted to a nerve signal. The signal passes along nerves to your spinal cord and brain. In your brain, the signal is perceived as pain. Opioid drugs affect how you feel pain. They attach to structures called opioid receptors. These receptors are found on cells in your brain, spinal cord, and other areas of your body. Opioids act on these receptors to make you feel less pain. These drugs can also have other effects on your body. For example, they may give you an intense short-term high and feelings of extreme happiness. Opioids also activate the ...