Sierra Mist soda/medication interaction

So I’m sitting here gulping down a diet Sierra Mist Ruby Splash soda when I suddenly remember because of some medication I’m on I’m not supposed to have any grapefruit or grapefruit juice.

A look at the label only says “with a splash of ruby grapefruit with other natural flavors” The ingredients say natural flavor, but doesn’t say theres any actual grapefruit in it. There is also no disclaimer saying “does not contain juice”.

I’m thinking if there is any grapefruit in this it’s probably quite a minute’ amount.

So what’s the dope? Am I putting myself in danger by drinking this stuff?

I would suggest asking your pharmacist. Natural flavor is sufficient to cover a small amount of grapefruit juice. My educated guess would be that it is too small an amount to be significant, since it takes a whole glass of grapefruit juice to get the maximum effect.

I don’t know if we have actual pharmacists on the Dope. The doctors will probably know a lot about this, too, but not as much as a pharmacist. And they might not be comfortable answering the question, anyways.

The problem with grapefruit is that it inhibits CYP3A4, an enzyme that is responsible for metabolism of many drugs. Depending on how your particular drug is metabolized, mainly if the drug is a prodrug or not, depends on if it raises or lowers the blood level of the drug in question.
This is concentration dependent, the amount of CYP3A4 that is inhibited is proportional to the amount of grape fruit juice injected. Since, in ingredient labels the items are listed in proportion to the amount of the ingredient in the product (the later the listing, the lower % in the product), I think the concentration of grapefruit juice is less then 0.05% of the product.

So, I REALLY doubt the little bit of grapefruit juice in that particular soda will clinically affect the effect (Please tell me I got the word usage right!) of your drug.

Hope that helps.


DISCLAMER: I am a Pharmacy Intern, just entered my 3rd year. This is just information on what is happening (a GQ answer), as for your particular case, you never gave the drug you are taking, so this is not advise on you in any way.

When my father was prescribed Lipitor, his doctor specifically told him he must no longer drink Fresca.

I imagine that there isn’t much less grapefruit in Sierra Mist than there is in Fresca.

If your Sierra Mist is anything like mine, most of it has leaked or evaporated before you even opened the can.

Don’t know why the Doctor specified Fresca, but the main difference (clinically) between Simvistatin (Zocor), and Atorvastatin (Lipitor), is that it isn’t metabolized by CYP3A4, so is not effected by grapefruit consumption.

Huh? Which one is not affected? I am on Simvastatin but the label says to avoid grapefruit.

As I understand it, though, it is not actually dangerous, it just reduces the effectiveness of the drug somewhat. (Maybe its worse for other drugs.)

According to my doctor it is dangerous. The grapefruit prevents the simvastatin from being broken down and used, and it accumulates in the body . . . with potentially disastrous consequences.

That’s significant. So the question remains: does this Sierra Mist have any actual grapefruit in it, or is does it just have a natural flavor that tastes like grapefruit? I can’t find anything on the web that says one way or the other.

Called Pepsi consumer relations and was told:

“if the product had actual grapefruit, grapefruit juice, or any other fruit, vegetable, or any other fruit/vegetable juice, they would have to be specifically listed on the ingredients list. The term ‘natural flavor’ does not cover fruit, vegetables, or fruit/vegetable juices. Therefore diet Sierra Mist Ruby Splash soda does not contain any grapefruit or grapefruit juice”

Which is good as I really like it and would have hated to give it up.

Unless someone posts conflicting information I guess the OP is answered. Thanks for your responses.:slight_smile:

Lipitor (atorvastatin) is also not to be taken with grapefruit ( PDF of prescribing info ), as well, just FYI. It also notes that the real trouble is with large quantities of grapefruit juice, but my feeling is that if you want to get the most out of your meds, you might as well make the allowances that let them work best.

pkbites, glad to hear you’re all set.

In case anyone is interested:

Here’s the definitive list of possible drug interactions with grapefruit juice (and a whole lot more).

Grapefruit juice is listed in the far right-hand column under the heading ‘inhibitors’.

That means that grapefruit juice, and all the other drugs/substances listed as inhibitors in the same column, inhibit the breakdown of the drugs in the same vertical column listed under ‘substrates’.

So, for example, grapefruit juice inhibits the breakdown of clarithromycin (Biaxin), alprazolam (Xanax), and atorvastatin (Lipitor).

My understanding is that Simvastatin (Zocor) has greater metabolism through CYP3A4 then Atorastatin (Lipitor). So, Grapefruit juice will have a greater effect on someone who takes Simvastatin then who takes Atorastatin.

With the Statin drugs (in particular, since the OP never did mention what drug was in question) grapefruit inhibits the metabolism of 'statins, so they build up in the blood. This causes a higher concentration of the drug then was prescribed.

This is a concentration depend process, so it matters what level of Grapefruit Juice there is, and also what the strength of the 'statin is.

In the case of this OP, since the Grapefruit juice is listed so low in the ingredient list, I would think it would be perfectly ok to continue drinking Sierra Mist.

Well, it can’t contain any significant amounts. I assume you’re not quaffing 5+ liters a day?

I like the stuff myself, wish I could find it in the smaller bottles (anything less than a liter, i.e the 12, 16 or 22 oz size).

Holy crap! Really? I’ve been on Lipitor for years now, and I’ve been drinking 2-3 cans of Fresca a day the whole time. My son and I love Fresca. I just bought another 12 cases yesterday because it was on sale.

I’ve heard that grapefruit juice could be a concern, but I always figured that there couldn’t be a whole lot of actual grapefruit juice in Fresca.

I get it in 12 packs of 12 ounce cans here. It was on sale last week four 12 packs for $10.98. Which is as cheap as I’ve seen major brand soda in quite a while.