Opiates are a class of drugs that are among the most prescribed in the U.S., but unfortunately also the most abused. Opiates include prescription painkillers intended for the treatment and management of moderate to severe pain, as well as illicit drugs like heroin.

It’s estimated that tens of millions of people abuse opiates throughout the world, including not just heroin but also morphineoxycodone, and other prescription medications. It’s estimated that there are hundreds of thousands of people struggling with heroin addiction in the U.S. alone, and the consequences of this epidemic continue to wreak havoc across the nation.

Opiate abuse comes with a broad range of long-term and short-term adverse side effects, including nausea and vomiting. People often wonder why opiates cause nausea, whether they’re taking them for clinically prescribed purposes or recreationally.

What Are the Effects of Opiates?

When someone takes an opiate, the drug attaches to opioid receptors located throughout the brain, spinal cord, gastrointestinal tract, and other organs. When opiates attach to these receptors, they reduce the perception of pain and create a sense of contentment or euphoria.

Opiates create a sense of pleasure because they affect the brain’s reward centers. As a person continues to take an opiate, they build up a tolerance to the drug’s effects, meaning they no longer have the same response to the drug they once did. This diminished effect can push people to take larger doses and seek out cheaper, more potent opiates, such as heroin.

Exploring Why Opiates Cause Nausea

There is the common misconception that when someone takes heroin or a prescription opiate and becomes nauseous, the nausea is caused by an allergic reaction. However, the mechanism by which opiates result in opioid-induced nausea and vomiting often involves multiple systems in the body.

When you have opiates in your bloodstream, a region in the brain’s medulla oblongata called the chemoreceptor trigger zone (CTZ) detects the presence of these chemicals. When opioid receptors in this area are triggered, nausea and vomiting are induced. Activation of the CTZ is thought to be the main pathway by which opiates cause nausea.

Additionally, opiates may trigger the vestibular system, which can cause nausea in some individuals. These medications can also slow down the entire gastrointestinal system, which may also elicit feelings of nausea.

When pondering why opiates cause nausea, there are some considerations to note. First, if people are taking opiates in a clinical setting such as a hospital, medications like dopamine antagonists, opioid antagonists or antihistamines can often be used to reduce nausea. Other medical options to reduce nausea from opiates can include adjusting doses, switching opiate medications or administering them by a different route.

Different people may experience nausea with opiates in different ways. Some people won’t experience nausea even with high doses, while others may have nausea and vomiting with only low doses of an opiate. Different opiates also have different risks of nausea.

After taking opiates for a short period, nausea may diminish or disappear altogether. However, if someone has developed a physical dependency on these drugs and they try to stop taking them, they may experience nausea and vomiting as part of opioid withdrawal.

Withdrawal can be dangerous, so a medical detox program can help you or a loved work through opiate addiction. The Recovery Village offers a continuum of care, including medical detox and inpatient and outpatient programs for opioid addiction. To learn more about available options, contact The Recovery Village today.

Megan Hull
Editor – Megan Hull
Megan Hull is a content specialist who edits, writes and ideates content to help people find recovery. Read more
Jessica Pyhtila
Medically Reviewed By – Dr. Jessica Pyhtila, PharmD
Dr. Jessica Pyhtila is a Clinical Pharmacy Specialist based in Baltimore, Maryland with practice sites in inpatient palliative care and outpatient primary care at the Department of Veteran Affairs. Read more
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The Recovery Village aims to improve the quality of life for people struggling with substance use or mental health disorder with fact-based content about the nature of behavioral health conditions, treatment options and their related outcomes. We publish material that is researched, cited, edited and reviewed by licensed medical professionals. The information we provide is not intended to be a substitute for professional medical advice, diagnosis or treatment. It should not be used in place of the advice of your physician or other qualified healthcare providers.