Genetics Hugely Influence Opiate Side Effects

July 27, 2012

The Stanford University School of Medicine just completed a study in which they found that an individual’s genetic makeup may be used to determine a patient’s response to a variety of commonly used painkillers. The research examined the biological underpinnings of the following opiate side effects:

Nausea
Tendency towards addiction
Disrupted breathing patterns
Itchiness
Sedation

These are often the physical manifestations experienced by patients after the use of opiate pain meds such as morphine, methadone and oxycodone. The study is set to be published in the journal Anesthesiology and enumerates significant findings that contribute to the understanding of why there is such inconsistency between patients in the effectiveness and comfort associated with the use of opiate drugs. For example, the scientists found that nausea, one of the most loathed side effects of any medication, is a response that is strongly influenced by the individual’s genes.

Twins Were Used to Examine the Amount of Genetics Tied to Opiate Side Effects

The Stanford scientists analyzed results from 121 pairs of twins in a randomized, double-blind, placebo-controlled experiment. Mild pain was induced and measured with the use of a heat probe and ice water both before and after receiving a short-acting opiate painkiller. The results showed the following percentages of heritability:

Respiratory depression: 30 percent
Nausea: 59 percent
Drug disliking: 36 percent
Itchiness: 38 percent
Dizziness: 32 percent
Drug-liking: 26 percent

Researchers Hope to Use This New Knowledge to Avoid Side Effects Like Addiction

The intent of this research is to use the results to provide better treatment plans for patients experiencing severe pain. The Stanford scientists believe genetics will eventually be able to assist doctors in making the following decisions to improve treatment:

How aggressive the drug protocol needs to be in order to be effective
How often a patient will need to be monitored for possible med changes
Whether or not a particular patient should be allowed to attempt long-term opioid treatment

Presently, the use of opiate medications for effective treatment of pain is an educated guess at best. Some patients may require 10 times the amount of a drug as others to get the same relief, while others will experience such intense side effects that the drugs can’t be prescribed. Then there are the individuals who quickly develop dependency on and addiction to opiate painkillers. The goal with genetic information is to learn how to sidestep these scenarios by predicting their potential ahead of time.

Dr. Martin Angst was the lead researcher for this study at Stanford. He explained that, despite our society’s heavy reliance on narcotic painkillers, “…we don’t know the answers to fundamental questions, such as why some people ‘like’ narcotics more than others – drug liking and disliking could be key in determining addiction potential.”

Do you think addiction can be predicted purely through genes? Let us know your thoughts below.