Opioid-Induced Itching

Quick Answer

If opioids leave you itching—especially around your face and nose—you're not having an allergic reaction in most cases. Opioids trigger the release of histamine and act directly on receptors in the brain and spinal cord that register itch, which is why the urge can feel deep and hard to scratch away. The good news: switching opioids, taking the right medication, and a few simple at-home steps can usually bring relief.

Doctors don’t know why opioids make their patients itch; however, researchers have identified several factors that could explain why the drugs cause itching.[1]

If you react poorly to one type of opioid, switching to a different version may help. Medications and at-home care could help too.

Why Do Opioids Make You Itch?

Opioids are prescription painkillers. They’re similar to illicit opiates (like heroin), but they’re made in controlled environments by chemists. Opioids work by latching to opioid receptors in the brain. Latching triggers euphoria, making pain signals easier to ignore.

Between 2% and 10% of people who use opioids develop itching. The risk is higher when people get their drugs via injection rather than swallowing pills.[2]

Itching is uncomfortable, but it’s rarely life-threatening. Most people with opioid-induced itching develop red, puffy, itchy skin and no other symptoms. With the proper treatment, they can be much more comfortable.

Where Opioids Make You Itch Most—and Why It's Often the Face

Many people are surprised that opioid itching concentrates on the face, nose, and upper body rather than everywhere. This happens because opioids act on itch-signaling receptors in the central nervous system and trigger histamine release near nerve endings that are dense in facial skin. Nasal itching in particular is a classic sign of opioid use. Because the itch is generated centrally (in the brain and spinal cord) as well as locally in the skin, scratching often provides little relief—which is why targeting the cause with the strategies below works better than topical fixes alone.

What Causes Opioid Itching?

Researchers believe opioids cause itching by activating the immune system, altering serotonin levels or triggering key brain centers associated with pain.[1] If your doses make you itch, you’re not necessarily allergic to them.

Opioids could make you itch due to the following issues:

• Histamines: Histamine is a neurotransmitter that your body could release in response to opioids.[3]
• Local reactions: Opioid receptors near your skin and around your hair could cause inflammation and itching when the drugs latch.[4]
• Brain changes: The medullary dorsal horn in the brain processes pain signals. Opioids can activate this brain center, causing itching.[1]
• Serotonin: Opioids can alter the serotonin system, changing heart rates and nervous system responses. Sometimes, that causes itching.[1]
• Pain: Your brain processes pain and itching similarly. Sometimes, a pain signal is interpreted as itching instead.

Is Itching a Side Effect or an Allergy?

Less than 2% of patients have a true allergy to opioids.[6] Those that do have severe side effects such as the following:

• Swelling of the lips, tongue, face or mouth
• Severe skin reactions (stronger than a mild rash)
• Shock
• Very low blood pressure

If your drugs spark mild redness and itching, you’re not experiencing an allergic reaction. Instead, your drug is working on well-known pathways that could lead to itching.

If you do experience severe allergic reactions to your Suboxone, contact your doctor immediately.

Which Opioids Cause Itching?

Most opioids can cause itching, including morphine, fentanyl, codeine, oxycodone (OxyContin) and hydrocodone (Vicodin). All opioids latch to receptors in the brain and body. The latching and resultant chemical changes can make you itch. Source[5]

Researchers know that some medications cause more severe itching than others. Stronger drugs (like fentanyl) tend to cause larger itch reactions than their weaker counterparts (like morphine). Source[6]

If you are struggling to discontinue opioid use, medications like Suboxone can help. Suboxone is a partial opioid itself. Like other opioids, it can also sometimes cause itching, but the itching may be less severe than someone taking full opioid agonists.

How Do You Stop the Itching From Opioids?

If your opioids make you itch, talk with your doctor. Together, you can create a plan to stop the discomfort.

Over-the-counter antihistamines can reduce itching responses caused by opioids, but they can cause sedation.[6] Prescription solutions, including those with promethazine, can be sedating too.[6] Your doctor can help you decide how to treat your itch. Never take antihistamines without checking first.

Antihistamines can be sedating, and opioids cause the same problem. Putting them together can lead to severe sedation. Never combine them without asking your doctor first.

If your itching is severe, your doctor may try a different drug in the same class. A simple swap like this could be enough to make the discomfort fade.

Always contact your doctor if your itching is severe, interferes with your breathing or impacts your opioid treatment.

Alternate Treatment Options for People on Suboxone With Itching

If you’re using MAT therapies like buprenorphine and itching begins, your doctor has several options to help you, such as these:

• Investigating: Other substances, medications and medical conditions could be the cause of itching. Your doctor can help you spot them.
• Switching: If buprenorphine causes itching, opting for methadone might be helpful.
• Dividing: Splitting your dose into several batches may help instead of taking them all at once.
• Waiting: Sometimes, the itch goes away as your body grows accustomed to the medication.

Itching can interfere with your sleep, make concentration difficult and just make life harder. It’s difficult to focus on your recovery when you’re dealing with an itch.

But never quit taking your medications without talking to your doctor first. Your recovery is important, and your doctor is a critical part of your team. Explain your itching and ask for help before you make any decisions.

Frequently Asked Questions

We’ve compiled some of the most frequently asked questions about opioid-induced itching.

How long does opioid-induced itch last?

Some people experience an itch the entire time they take opioids. Others notice their symptoms fade within a week or two.

How can I tell the difference between an opioid allergy and a side effect?

Severity is the main difference between allergies and side effects. A true opioid allergy causes severe symptoms like skin lesions, swollen eyes, low blood pressure and difficulty breathing. Mild itching is a side effect, not a symptom of an opioid allergy.

What are other common side effects of opioid use?

Opioids can cause side effects like constipation, sedation and nausea. Continued use can lead to dependence (needing to use the substance consistently to feel normal) or opioid use disorder (an inability to quit when you want to).  

Why does my face and nose itch the most when I take opioids?

Opioid itch is usually a normal side effect, not an allergy. Opioids can trigger histamine release near nerve endings in the skin and also act on itch signals in the brain and spinal cord. The face, neck, and upper chest tend to be affected most, which is linked to the dense network of opioid-sensitive nerves serving the face. Because the itch is generated centrally as well as in the skin, scratching often brings little relief, so targeting the cause works better than scratching.

Do antihistamines like Benadryl actually stop opioid-induced itching?

Over-the-counter antihistamines, the class Benadryl belongs to, can reduce opioid itching, but they cause sedation, and so do opioids, so combining them can lead to severe sedation. Never pair them without checking with your doctor first. And because opioid itch is driven largely by the central nervous system rather than histamine alone, antihistamines may only partly help, which is why switching opioids or treating the cause is often more effective.