A short YouTube clip by Dr. Peter Antevy explaining how codeine is metabolized in the liver to morphine via a cytochrome P450 (CYP) enzyme. He describes genetic variability in CYP activity: ultra-rapid metabolizers can produce much higher morphine levels (up to ~80× normal), while poor metabolizers produce little morphine. The clip is framed as a caution about giving codeine—especially to children or certain populations—because of these metabolic differences.
Questions this video answers
Up to about 80 times the normal amount.
Hi, everyone, My name is Peter Hentevi. Welcome to another edition of the Hantevi Minute. Today I wanted to talk about a very cool thing with regards to codeine and morphine. So many, many of you may have given codeine to your children or you give codeine to your patients. Let's talk about how codeine is metabolized and how it could be severely implicated in adverse outcomes for your patients. So if we talk about codeine.
The interesting thing about codeine is that it has to go through the liver to get metabolized. So this is your liver. Codeine goes into the liver and then it actually comes out as morphine.
But it turns out that in the liver there's an enzyme. Let's just call that enzyme CYP. It's a cytochrome P450, let's call it CYP. So it turns out that there are some people whose CYP is very, very active. They're basically called ultra metabolizers. And so the amount of morphine coming out from some people is very, very high because the codeine gets metabolized so quickly that the morphine concentration in your bloodstream can be up to 80 times the normal amount. Then there are some people who don't metabolize the codeine well at all. So the amount of morphine here.
Actually very low. So it's not really useful. And so there have been many case reports of mainly African Americans and children, adults. But really, if you're an African American, you have up to 34% chance that you could be an ultra rapid metabolizer of codeine. And so codeine really has been taken off the shelves at many pediatric hospitals. Be very careful when you give codeine to your patients at all, because that coding can lead to a very high spike in morphine concentration, respiratory depression, and ultimately death. So again, thank you for joining me today. Another edition of the Hentebi Minute. I'm Dr. Peter Rentebi. Take care.
