Codeine causes a histamine response in the body and therefore can cause itching in some who use this substance. Options are available if it becomes unbearable.

Does codeine make you itchy? If so, why does codeine make you itch? These are common questions. This overview covers what codeine is and why it can make some people itchy.

Article at a Glance:

  • Itchiness is a common symptom of codeine use.
  • Codeine can make you feel itchy because it triggers a histamine response when it binds to a certain receptor in the central nervous system.
  • If prescribed, you may be able to take an antihistamine or switch to another medication if the itching is unbearable for you.

Itchiness – A Common Opioid Side Effect

Even though codeine is one of the least potent opioids, it does have potentially adverse side effects. Itchiness is a common side effect of codeine and other opioids, affecting roughly 20% to 25% of people who take opioids.

Some of the most common side effects of codeine also include nausea, vomiting, dizziness, feeling lightheaded, feeling drowsy and constipation.

Why Does Codeine Make You Itch?

In the past, researchers believed painkillers made people itch because of how they affect the central nervous system; however, recent research has shown that there is a particular opioid receptor that creates this effect. When this certain receptor is activated following codeine use, it can release inflammatory substances, including histamine.

Codeine and other opioids make your body think that inflammation is occurring because of an allergen. As your body tries to clear itself of the allergen, an allergic-like response (which includes itching) can occur.

People often confuse the itching that occurs with opioids with an allergy, which doctors have started to refer to as a pseudoallergy. Because this certain receptor is activated by codeine and opioids, it can seem very much like an allergic response. This leads to many people being incorrectly identified as having a codeine or opioid allergy when this isn’t actually what’s happening.

Addressing Skin Irritation & Itchiness From Codeine Use

To address the itchiness associated with prescription painkillers, some doctors will give patients antihistamines before giving them these drugs. In other cases, they might change them to a different class of painkillers if it becomes too much for the patient to deal with.

Codeine tends to make people itch even more than stronger opioids for reasons that are currently being evaluated. In some cases, the answer is to have patients take a different type of opioid if they’re having a lot of itchiness while using this drug.

Rob Alston
Editor – Rob Alston
Rob Alston has traveled around Australia, Japan, Europe, and America as a writer and editor for industries including personal wellness and recovery. Read more
Kevin Wandler
Medically Reviewed By – Dr. Kevin Wandler, MD
Kevin Wandler holds multiple positions at Advanced Recovery Systems. In addition to being the founding and chief medical director at Advanced Recovery Systems, he is also the medical director at The Recovery Village Ridgefield and at The Recovery Village Palmer Lake. Read more
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Geneva: World Health Organization. “WHO Guidelines for the Pharmacological and Radiotherapeutic Management of Cancer Pain in Adults and Adolescents, Table A6.2.” 2018. Accessed June 28, 2020.

Robinson, G. M., Robinson, S., McCarthy, P., & Cameron, C. “Misuse of over-the-counter codeine-containing analgesics: dependence and other adverse effects.” 2010. The New Zealand Medical Journal, June 25, 2010. Accessed June 28, 2020.

Chung, K. F. “Drugs to suppress cough.” Expert Opinion on Investigational Drugs, January 2005. Accessed June 28, 2020.

Babina, M. “The pseudo-allergic/neurogenic route of mast cell activation via MRGPRX2: discovery, functional programs, regulation, relevance to disease, and relation with allergic stimulation.” International Forum for the Study of Itch. April 7, 2020. Accessed June 28, 2020.

Lansu, K. “Ligand Discovery and Functional Characterization of MRGPRX Family Orphan GPCRs” The University of North Carolina at Chapel Hill, December 2017. Accessed June 28, 2020.

Medical Disclaimer

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.