10 Gemfibrozil Interactions and How to Manage Them

GoodRx Health

Life comes with its fair share of disagreements. Conflicts between friends, families, and foes happen all too often. And nobody's immune to them.

The same is true about disagreements between medications - better known as drug interactions. Interactions pose an issue for anyone who takes medications or supplements. Some medications don't have many of them, while others have quite a few. Gemfibrozil (Lopid), a prescription medication for high triglycerides, falls toward the latter end of the spectrum.

Here, we'll review 10 notable gemfibrozil interactions and how to keep them in check. But keep in mind that this isn't a comprehensive list. Your pharmacist can review your full medication list to check for other possible interactions.

1. Simvastatin and rosuvastatin

Gemfibrozil tends to cause interactions because of how it interferes with specific proteins in the liver. Gemfibrozil makes it harder for the liver to metabolize other medications that depend on these proteins for their natural breakdown. As a result, there's an increased risk of side effects from the interacting medication.

This is particularly true with the statin cholesterol medications simvastatin (Zocor, FloLipid) and rosuvastatin (Crestor). Gemfibrozil, simvastatin, and rosuvastatin can all cause muscle problems on their own. But taking either statin with gemfibrozil significantly increases the risk of muscle pain and a severe muscle condition called rhabdomyolysis.

If you take gemfibrozil, it's best to avoid taking simvastatin or rosuvastatin because of the potential health complications. Other cholesterol medications are safer to take with gemfibrozil.

Good to know: If necessary, you may be able to take a smaller dosage of rosuvastatin - no more than 10 mg daily - with gemfibrozil. But your healthcare professional should make this call.

2. Other statins

While simvastatin and rosuvastatin pose the greatest risk, all statins can interact with gemfibrozil. So it's best to avoid this combination completely in most cases. Again, this is due to risks related to muscle pain and rhabdomyolysis.

Depending on the situation, your healthcare professional may decide that it's worth trying a low statin dosage. But that decision is made on a case-by-case basis.

Other statins include:

• Atorvastatin (Lipitor)

• Pravastatin

• Lovastatin (Altoprev)

• Pitavastatin (Livalo, Zypitamag)

• Fluvastatin (Lescol XL)

3. Colchicine

Colchicine (Colcrys, Mitigare, Gloperba) is an oral, prescription-only medication that's most often used for gout attacks. Like statins, colchicine can cause muscle aches and other muscle problems as a side effect. This risk is higher when it's combined with gemfibrozil. And older adults and people with kidney problems are at the highest risk.

If you have gout, your healthcare professional will likely prescribe you a different gout medication that doesn't interact with gemfibrozil. But if the combination is necessary, they'll want to monitor you closely for muscle-related side effects.

4. Uptravi

Uptravi (selexipag) is an oral and injectable medication that treats pulmonary arterial hypertension (PAH). Uptravi is effective at slowing down the progression of PAH. But it's another medication that should be avoided with gemfibrozil.

Compared to the interactions above, this interaction is caused by a different set of liver proteins. But the end result is similar: issues with how Uptravi is metabolized. This can lead to new or worsening Uptravi side effects, which may include diarrhea, joint pain, and muscle pain.

In the past, not many PAH medications were available. But many more have obtained FDA approval in recent years. Your healthcare professional can work with you to find a PAH treatment that doesn't interact with gemfibrozil.

5. Oral diabetes medications like repaglinide

A few oral Type 2 diabetes medications interact with gemfibrozil. Combining these medications with gemfibrozil raises the risk of hypoglycemia, or low blood glucose (sugar).

The biggest risk is with repaglinide. Combining gemfibrozil and repaglinide, which can cause severe hypoglycemia, should be avoided altogether. But pioglitazone (Actos) and sulfonylureas like glipizide (Glucotrol XL) and glyburide (Diabeta, Glynase) pose an issue, too. Depending on your personal risks, your healthcare professional may want you to avoid these medications or take a lower dosage.

There are many other oral and injectable medications that are used to treat Type 2 diabetes. So avoiding a potential interaction shouldn't be an issue.

6. Bile acid sequestrants

Colestipol (Colestid), colesevelam (Welchol), and cholestyramine (Prevalite, Locholest) are all bile acid sequestrants that treat high cholesterol. For many, they're useful statin alternatives. But they can attach to gemfibrozil - and several other medications - if they're in the gut at the same time. This may make gemfibrozil less effective.

You don't need to completely avoid bile acid sequestrants if you take gemfibrozil. But try to space out the times you take the medications. Do your best to separate doses of gemfibrozil and your bile acid sequestrant by at least 2 hours to avoid issues.

For example, if you take a dose of cholestyramine at 8AM, you shouldn't take a dose of gemfibrozil until 10AM at the earliest (or vice versa).

7. Loperamide

Like prescription medications, over-the-counter (OTC) products and dietary supplements can cause interactions. Loperamide (Imodium A-D) is a popular OTC treatment for diarrhea related to a number of causes. This includes traveler's diarrhea, diarrhea from gastrointestinal conditions, and even medication-induced diarrhea.

As with the interactions above, gemfibrozil can interfere with the proteins that break down loperamide. This may lead to new or worsening loperamide side effects, such as drowsiness, dizziness, or constipation.

If you have diarrhea, ask your healthcare professional if loperamide is safe for you to try. Depending on your medical history, they can tell you if it's OK to take it or if it'd be safer to try a different diarrhea treatment, such as bismuth subsalicylate (Pepto-Bismol). They can also walk you through dietary tips for lessening diarrhea.

8. Montelukast

Montelukast (Singulair) is an oral medication that's occasionally used to treat seasonal allergies and asthma. Gemfibrozil can cause montelukast levels to rise in the body due to impaired metabolism. And side effects are more likely to happen as a result.

If you need to take both medications, your healthcare professional will likely monitor you closely for side effects. In most cases, it's not necessary to avoid this combination or adjust the montelukast dosage.

9. Warfarin

It's no secret that many medications and foods can affect warfarin (Coumadin, Jantoven) levels. That's part of why it's recommended to get regular blood tests while taking the blood thinner. Some combinations worsen the risk of bleeding from warfarin, while others can make the medication less effective.

Gemfibrozil makes accidental bleeding from warfarin more likely. It can amplify the effects of the medication without added benefit and potentially raise your international normalized ratio (INR).

Taking warfarin and gemfibrozil together is a balancing act. If you take warfarin and then start taking gemfibrozil, your healthcare professional will likely lower your warfarin dosage out of caution. They may also do this if your gemfibrozil dosage increases at any point. On the other hand, if you stop taking gemfibrozil or switch to a lower dosage, you may need to raise your dosage of warfarin.

If you're taking this combination, do your best to monitor for signs of accidental bleeding on your own. If you notice blood in your stool or urine or bleeding in your gums, reach out to your healthcare professional right away.

10. Several cancer medications

Cancer medications are life-saving and life-extending treatments. But, like with all medications, they come with some risks.

People often think about the side effects of cancer treatments. But these medications also have risks related to drug interactions. This is true for many cancer medications - no matter if it's chemotherapy, immunotherapy, or targeted therapy.

Notable cancer medications that can interact with gemfibrozil include:

• Paclitaxel

• Xtandi (enzalutamide)

• Tafinlar (dabrafenib)

• Gleevec (imatinib)

• Tukysa (tucatinib)

• Ojemda (tovorafenib)

Before you start receiving cancer treatment, your oncologist should do a thorough review of the medications and supplements you take at home. This is done to make sure your treatment plan meshes well with everything else you take. Depending on the situation, they may ask you to hold off on taking gemfibrozil until your cancer treatment is finished.

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