Gene changes linked to how we process codeine

Codeine is a common drug given for pain. But codeine itself does not help with pain. The body has to activate it first. A protein in your liver activates the drug. It turns codeine into morphine. Morphine is what helps ease the pain. But the protein that activates the drug does not work well in some people. For others, it might not work at all. About 1 in 8 people get little to no pain relief when they take codeine. A few people have extra copies of the gene that makes that protein. They get very fast relief from pain. But they also get side effects linked to high doses. Scientists know that changes in the gene that makes this protein cause these effects. But, no one has tested this in people. So, researchers at Vanderbilt will use BioVU to look for patients for whom codeine did not work well. Then they will check for gene changes. They hope to link the gene changes to less pain relief. Their results could help us predict for whom codeine will and will not work well. If we know someone has gene changes that affect how the drug will work, we can give them a different drug. That way, we can make sure people get the right amount of pain relief they need.