Opioid Pain Killer Side Effects - Which Factors Contribute?

Date: Jun-22-2012Morphine, methadone and oxycodone are all powerful opioid medications that are prescribed to millions of patients in the United States each year. However, these drugs have severe side effects including addiction, itching, nausea, and the slowing or stopping of breathing.

In a study published in the July issue of Anesthesiology, researchers at Stanford University set out to determine why some individuals are more susceptible to these adverse effects than others.

Study author Martin S. Angst, M.D., explained: "One of the most basic questions we asked is to what extent genetic versus environmental factors determine individuals' susceptibility to adverse opioid effects."

The researchers enrolled 121 pairs of identical and fraternal twins to participate in the study. The mu-opioid receptor agonist alfentanil and saline placebo were administered as target-controlled infusions under monitored laboratory conditions. The researchers assessed aspects of participants mood and sleep and also collected demographic information.

Measured outcomes of the study included:
nausea
sedation
itching
liking and disliking of the drug
respiratory depression


The researchers found that drug disliking and liking could be associated to how susceptible the participant is to becoming addicted to pain killers. Furthermore, they found that the degree to which participants experience drug disliking, slowed breathing and nausea was likely to be influenced by genetic factors. Genetic and environmental factors were also associated to how much a study participant enjoyed the opioid infusion. Adverse effects were also influenced by factors, such as psychological status, age, and sex.

David J. Clark, M.D., Ph.D., explained:

"Our findings provide strong support to focus additional studies on the specific genetic makeup of individual patients who are more susceptible to adverse outcomes associated with opioid use. Since side effects are common among patients who use opioid medications, it will be beneficial to use such research to help at-risk patients avoid serious life-threatening complications."

Dr. Angst said: "The study is a significant step forward in efforts to understand the basis of individual variability in response to opioids and to eventually personalize opioid treatment plans for patients."

Written By Grace Rattue

View drug information on Oxycodone and Aspirin.

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