Most people use oxycodone for pain relief, and some abuse the drug for its euphoric effects. But the popular opioid can also cause a number of unwanted side effects, including itching.
Up to one in 10 people who take oral opioids experience itching, and itching is more likely with higher doses of drug. Most of the time, itching occurs on the face, but some people may experience generalized itching on other parts of their body.
Until fairly recently, it wasn’t understood exactly why opioids make people itch. But science is shedding new light on the frustrating phenomenon.
When itching accompanies the use of a medication, we often worry about an allergic reaction.
While it is possible to have an allergic reaction to oxycodone, true allergies to opioids are extremely rare. According to a 2018 article in the Pharmacy Times, they occur in less than 2 percent of patients.
Most of the time, opioid-related itching is simply an adverse effect of the drug and isn’t dangerous in and of itself.
Itching doesn’t necessarily mean you’re allergic to oxycodone, but you might be.
Any opioid, including oxycodone, can trigger an allergy — but allergies are more common with codeine, morphine and meperidine. Opioids can also cause another type of hypersensitivity reaction known as a “pseudoallergy,” which is usually less severe than an actual allergy.
True opioid allergies usually cause a constellation of serious symptoms including: rash, headache, trouble swallowing, and swelling of the lips, tongue and face. In severe cases, a person’s throat may close, their blood pressure can plummet, and they can die.
Pseudoallergies, on the other hand, typically cause flushing, hives and mild itching. A pseudoallergy can also cause an elevated heart rate and low blood pressure and asthma-like symptoms, but life-threatening reactions are rare.
Another key difference between a true allergy and a pseudoallergy is the time at which it occurs. A pseudo-allergic reaction can occur the first time a person takes a drug, whereas a true allergy requires repeated exposure to the drug.
In most cases, though, itching is simply a harmless — but annoying — side effect stemming from the way oxycodone affects the nervous system.
Scientists have long known that opioids work by attaching to opioid receptors in the brain and spinal cord and blocking pain signals. But more recently, they’ve discovered that specific opioid receptors also trigger severe itching.
In 2011, researchers at the Washington University School of Medicine in St. Louis isolated a specific opioid receptor called MOR1D that appears to trigger itch. In animal studies, the scientists were able to alleviate opioid-related itching by blocking MOR1D.
“When we blocked MOR1D, mice that got morphine no longer needed to scratch, and they still received the same level of pain relief,” said Zhou-Feng Chen, director of Washington University’s Center for the Study of Itch and the principal investigator on the study, said in a press release.
Better understanding of how opioids trigger itching may help to pave the way for new itch-free painkillers. But in the meantime, there are few effective remedies for oxycodone itching.
Opioid-related itching is sometimes treated with antihistamines, such as diphenhydramine and hydroxyzine, but these drugs are not always helpful and can cause excessive drowsiness and dry mouth. Capsaicin, a topical ointment derived from chili peppers, may provide relief for some.
The drug naloxone is generally effective in relieving opioid-related itching, but it can also reduce or negate oxycodone’s painkilling effects. Naloxone — which is usually given in emergencies to reverse an opioid overdose — will also bring on oxycodone withdrawal symptoms in someone who is physically dependent on the drug.
A 2016 study in the Clinical Journal of Pain found that a synthetic opioid called nalbuphine was “superior” to diphenhydramine and other medications in treating opioid-related itching and “should be used as a first-line treatment” for the problem. Nalbuphine — which is sold under the brand names Nubain and Nalpain — has the added benefit of reducing nausea and vomiting, according to the study.
Like other oxycodone side effects, itching may resolve over time as a person continues to take the drug. With one-time use, itching will subside when the body metabolizes and eliminates the medication. But ceasing use may be difficult in someone who has developed an oxycodone addiction.
Other Addiction Topics
Get cost-effective, quality addiction care that truly works.
Start Your Recovery