Opioid drugs like codeine, hydrocodone (Vicodin), and oxycodone (OxyContin, Percocet) treat pain. These drugs are very effective, but they’re also highly addictive. Up to 12 percent of people who are prescribed opioids for chronic pain develop a dependence on these drugs.

Opioids are believed to change brain chemistry and alter the brain’s pleasure-reward circuits. When you take an opioid, it produces feelings of intense euphoria or relaxation. For some people, these feelings make it hard to stop taking the drug.

Using opioids long-term can lead to dependence, which means you need to keep taking the drug just to function.

Opioids are a class of drugs that are commonly prescribed to treat pain. Opioids include both opiates (drugs derived from the opium poppy, including morphine, codeine, heroin, and opium) and synthetic opioids like hydrocodone, oxycodone, and methadone, which have similar effects. Prescription opioids include: Oxycontin (oxycodone), Vicodin (hydrocodone and acetaminophen), Dilaudid (hydromorphone), and morphine.

Although very useful to treat pain, these drugs can cause physical dependency and addiction. According to the National Institute on Drug AbuseTrusted Source, approximately 2.1 million people in the United States and between 26.4 and 36 million people worldwide abuse opioids.

Certain illegal drugs, such as heroin, are also opioids. Methadone is an opioid that is often prescribed to treat pain, but may also be used to treat withdrawal symptoms in people who have become addicted to opioids.

Kratom, an herbal extract from the leaves of an evergreen tree (Mitragyna speciosa) that grows in Southeast Asia, is one substance that is promoted as a treatment for withdrawal. Kratom is sold as a dietary supplement and is not currently regulated in the United States, but federal agencies are taking action to combat false claims about kratom.

In Asia, people have used kratom in small amounts to reduce fatigue or treat opium addiction. In other parts of the world, people take kratom to ease withdrawal, feel more energetic, relieve pain, or reduce anxiety or depression. People take kratom to ease withdrawal because kratom evokes feelings of euphoria and may be obtained more easily than drugs prescribed for withdrawal.