13 Medications That May Cause Diarrhea

Most diarrhea will resolve by itself without any treatment within 2 weeks. This can include causes like gastroenteritis (a stomach bug) or food-borne illness. 

If your diarrhea is hanging on and not resolving, take a look at your medications. At least 700 medications can cause diarrhea as a side effect. Among these, medications like antibiotics, metformin, and sertraline (Zoloft) can cause diarrhea. 

It can be challenging to identify which medication may be causing diarrhea, especially if you’re taking multiple medications. Here are 13 well-known medications that are associated with diarrhea.

1. Antibiotics

Up to 30% of people taking antibiotics can have diarrhea caused by taking the antibiotic. This can happen within a few days of treatment, or even up to 2 months after finishing it. 

Certain antibiotics have a higher chance of causing diarrhea. These include: 

• Aminopenicillins, like amoxicillin (Amoxil) or amoxicillin/clavulanate (Augmentin)

• Cephalosporins, like cephalexin

• Clindamycin (Cleocin)

2. Metformin

Metformin is a commonly used medication used to lower blood sugar in people with Type 2 diabetes. It’s often the first medication used for diabetes.

Many people who take metformin complain of diarrhea. It’s the most common side effect of this medication and can happen in up to 63% of people taking it. Taking metformin at meal times or using the extended-release version of metformin — metformin ER (Glucophage XR) — can help reduce diarrhea.

3. Antidepressants (especially Zoloft)

Selective serotonin reuptake inhibitors (SSRIs) are antidepressants used to treat conditions like depression and anxiety. Examples of medications in this class are:

• Zoloft

• Prozac (fluoxetine)

• Lexapro (escitalopram)

Up to 16% of people taking SSRIs can develop diarrhea. Zoloft seems to cause diarrhea more than other antidepressants. One study found that 14% of people taking Zoloft developed diarrhea, compared to about 7% for other SSRIs.

4. Beta Blockers

Beta blockers are medications that treat many different heart conditions, including high blood pressure, heart failure, and atrial fibrillation. Common examples of beta blockers include: 

• Metoprolol (Lopressor, Toprol XL)

• Atenolol (Tenormin)

• Carvedilol (Coreg)

Diarrhea is a known side effect of beta blockers. But most of the time, if you have diarrhea and you’re taking a beta blocker, the diarrhea is not caused by the beta blocker. This means a person would have had diarrhea even if they weren’t taking the medication. For example, a study found that out of 100 people taking a beta blocker who had diarrhea, only 28 cases were caused by the medication.

5. ACE Inhibitors and ARBs

Angiotensin-converting enzyme (ACE) inhibitors and angiotensin II receptor blockers (ARBs) are medications that are commonly used to treat high blood pressure, as well as other conditions like heart failure and kidney disease. Both ACE inhibitors and ARBs can cause diarrhea.

Diarrhea is a reported side effect of several ACE inhibitors including lisinopril (Prinivil, Zestril) and ramipril (Altace). But, it’s not a common side effect. For example, in studies of ramipril, 1% of people taking the medication had diarrhea, and 0.4% of people taking placebo (a pill with no medication in it) had diarrhea. So, there’s only a small chance you could have diarrhea from taking an ACE inhibitor.

Similarly, diarrhea is a reported side effect of ARBs including losartan (Cozaar) and valsartan (Diovan). But similar to ACE inhibitors, diarrhea is not a common side effect for ARBs. Studies of valsartan found that diarrhea occurred in 5% of people taking the medication and 4% of people taking placebo. So just as with ACE inhibitors, there’s only a small chance of ARBs causing diarrhea.

The exception to this is olmesartan (Benicar). Although rare, this medication can cause a severe form of diarrhea and weight loss called enteropathy. There have been several cases reported where olmesartan caused these symptoms. So if you experience diarrhea after starting olmesartan, be sure to contact your healthcare provider.

6. Acid reducers

Several types of acid reducers can cause diarrhea, including:

• Proton pump inhibitors (PPIs)

• Histamine-2 (H2) antagonists

• Magnesium-containing antacids

 Each of these medication classes can help with heartburn, among other conditions.

Almost 4% of people taking PPIs report having diarrhea, and there’s not one PPI that seems to be more likely to cause diarrhea. Examples of PPI medications include omeprazole (Prilosec), pantoprazole (Protonix), and esomeprazole (Nexium).

Diarrhea is also a reported side effect of H2 antagonists, such as famotidine (Pepcid AC) and cimetidine (Tagamet HB). For famotidine, diarrhea is listed as one of the most common side effects.

Magnesium is a mineral that your body needs to function properly. It can be taken as a supplement, as a combination antacid aluminum hydroxide/magnesium hydroxide/simethicone (Mylanta, Maalox), or as a laxative (magnesium citrate). Magnesium works as a laxative by drawing water into the bowels, helping with stool movement. This is also how it can cause diarrhea, if you get too much magnesium.

7. Digoxin

Digoxin (Lanoxin) is a heart rhythm medication that can be used for heart failure and atrial fibrillation. Diarrhea is not a common side effect of digoxin, but it can happen.

You’re more likely to get diarrhea from digoxin if you get too much of this medication. Digoxin is thought to cause diarrhea by blocking the enzyme (protein) ATPase. Blocking this enzyme disrupts fluid and electrolyte balance in the bowels.

8. Colchicine

Colchicine (Colcrys, Mitigare) is a medication used to treat gout, and diarrhea is one of its most common side effects. Diarrhea has been reported in up to 23% of people taking this medication.

Colchicine may cause diarrhea by blocking the action of ATPase and disrupting fluid balance in the bowels, similar to digoxin.

9. Lithium

Lithium is a medication used to help regulate mood swings caused by bipolar disorder. Diarrhea is a common side effect that happens from taking lithium — it can happen in up to 10% of people. This side effect is most common during the first 6 months of taking lithium. It’s possible you may experience more diarrhea at the 6-month mark than you did right after starting it.

Diarrhea from taking lithium may be more common if you have high lithium blood levels or if you take an extended-release form of lithium (Lithobid).

10. Levothyroxine

Levothyroxine (Synthroid, Tirosint, Unithroid) is a synthetic thyroid hormone used for the treatment of hypothyroidism (low thyroid hormone). Diarrhea is a reported side effect of levothyroxine. 

This is likely due to the possibility of getting too much thyroid hormone from taking levothyroxine. High levels of thyroid hormone can cause diarrhea — up to 25% of people with hyperthyroidism (too much thyroid hormone) complain of diarrhea. 

If you notice you start having diarrhea after starting or changing your dose of this medication, contact your healthcare provider. They may want to check your thyroid hormone levels to make sure your dose isn’t too high.

11. Fibrates

Gemfibrozil (Lopid) and fenofibrate (Tricor, Trilipix) are fibrate medications used to lower triglycerides and “bad cholesterol” (LDL), while raising “good cholesterol” (HDL). 

Diarrhea is listed as a common side effect for both gemfibrozil and fenofibrate. But, diarrhea doesn’t seem to happen that much more than placebo. For example, studies showed that slightly more than 7% of people taking gemfibrozil reported having diarrhea, versus a little over 6% of people taking placebo. 

12. Vitamin C

Vitamin C is an important vitamin for the body. It helps with immune system function, regulates inflammation, and helps with iron absorption. It can cause diarrhea, especially if you’re taking high doses (2 to 6 grams per day). Usually, the diarrhea improves when you stop taking vitamin C.

13. NSAIDs

Nonsteroidal anti-inflammatory drugs (NSAIDs) are medications that help treat pain and inflammation. Common examples of NSAIDs are:

• Ibuprofen (Advil, Motrin)

• Naproxen (Aleve, Naprosyn)

• Meloxicam (Mobic)

Although the overall risk of diarrhea is less than 1%, NSAIDs can sometimes cause severe, fast-onset diarrhea. 

How long does medication-induced diarrhea last?

Medication-induced diarrhea can last for a few days (acute diarrhea), or as long as 3 to 4 weeks (chronic diarrhea). Medication-induced diarrhea most often occurs right after starting a medication. Less often, a medication can cause diarrhea even if you’ve been taking it for a while.

If the diarrhea is caused by a medication, it tends to continue unless you stop taking the medication. In some cases though, diarrhea can resolve on its own.

How do you stop diarrhea from medication?

As discussed, the most common way to stop medication-induced diarrhea is to stop the medication that is causing it. Always talk to your healthcare provider before stopping a medication. Depending on what condition it’s treating, stopping a medication on your own can be risky or make your condition worse.

Your healthcare provider may also recommend other treatments to help with medication-induced diarrhea, such as fiber supplements or anti-diarrheal medications.

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Written by:

Austin Ulrich, PharmD, BCACP

Austin Ulrich, PharmD, BCACP, is a board-certified ambulatory care clinical pharmacist. In his early career, he provided direct patient care in a variety of settings, including hospital and community pharmacies, and in a primary care clinic as a clinical pharmacist.

Edited by:

Samvida Patel, MNSP, INHC

Samvida Patel, MNSP, INHC, is a health editor at GoodRx. She is a nutritionist and integrative nutrition health coach with over 8 years of experience in health communications.

Reviewed by:

Christina Aungst, PharmD

Christina Aungst, PharmD, is a pharmacy editor for GoodRx. She began writing for GoodRx Health in 2019, transitioning from freelance writer to editor in 2021.

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