Can You Crush Metformin?
In our latest question and answer, the pharmacist discusses whether or not metformin can be cut, split or crushed.
I'm diabetic and take metformin. The tablets are really large, so I'm wondering if I can crush them and take them that way.
- Metformin extended-release products (Glucophage XR, Fortamet, Glumetza, and associated generics) should not be cut, split, or crushed.
- Immediate-release metformin products can safely be cut, split, or crushed.
- Crushing, cutting or splitting an extended-release metformin product will destroy the release mechanism, causing the entire dose to be released at once.
Hello and thank you for reaching out!
Being a pharmacist and having seen my fair share of metformin tablets, I certainly know how large they are, and how they can be difficult to swallow.
Extended-release metformin tablets cannot be crushed or cut, while immediate-release tablets can be.
Different metformin Products
In fact, there are five different branded metformin products (and associated generics):
- Glucophage XR
Riomet is an oral solution so that one is not applicable to this question.
Glucophage XR, Fortamet, and Glumetza are all extended-release metformin products, and, I imagine, you may be wondering why there are so many, and how they differ.
While they all contain extended-release metformin, the release mechanism for each is different:
- Glucophage XR utilizes a 'dual hydrophilic polymer matrix'
- Fortamet uses 'osmotic technology'
- Glumetza uses 'gastric retention technology'
There isn't too much of a clinical difference between any of these, and going into detail about the different extended-release mechanisms isn't really the point of this answer, so the main takeaway here is that none of them can be cut or crushed.
Crushing metformin (Immediate-Release Only)
As mentioned, only immediate-release metformin can safely be crushed or cut.
If you are having trouble swallowing the tablets (they are large), crushing or cutting is certainly an option.
There are a number of generic manufacturers of immediate-release metformin tablets, and some have a 'score' mark, making them easier to cut. If your pharmacy stocks the scored tablets, I'd recommend requesting those.
I also want to note that if you plan on crushing immediate-release tablets, they are not flavored or sweetened, so you'll want to mix the crushed powder with some type of food (typically applesauce or pudding is recommended) and take it that way.
Why You Can't Crush Extended-Release metformin
If you crush extended-release metformin products (e.g. Glucophage XR, Glumetza, Fortamet, and associated generics), the extended-release mechanism of the tablet will be destroyed.
Instead of releasing the drug over a long period of time as intended, the entire dose gets released at once, which negates the benefits of the tablet in the first place.
Extended-release metformin products do have an advantage over immediate-release ones as most individuals taking them report they are better tolerated in terms of side effects (less nausea, cramping, etc...). Additionally, they are generally dosed only once daily, instead of multiple times daily, making them more convenient.
I mention this just to emphasize the point that there is a reason why your doctor prescribed you the extended-release form. If you destroy the tablet, you lose the benefits of that extended-release mechanism.
As a final point here, the prescribing information for all the extended-release products warn not to crush them. The following is from the FDA approved prescribing information for Glucophage XR:
Patients should be informed that GLUCOPHAGE XR must be swallowed whole and not crushed or chewed, and that the inactive ingredients may occasionally be eliminated in the feces as a soft mass that may resemble the original tablet.
Thanks again for reaching out to us! I hope this answer helps!
- Dr. Brian Staiger, PharmD
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