5 Pepcid Side Effects You Should Know About
Key takeaways:
Pepcid (famotidine) is a common over-the-counter and prescription heartburn medication. It doesn’t typically cause side effects for many people who take it.
Mild Pepcid side effects include headache and dizziness. Stomach-related side effects, such as diarrhea or stomach pain, are also possible.
Rare but serious Pepcid side effects include liver damage and brain-related side effects, like confusion. In severe cases, these side effects may require immediate medical attention.
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Table of contents
Pepcid (famotidine) is a common medication that can treat issues caused by too much stomach acid. Examples include heartburn and gastroesophageal reflux disease (GERD). Pepcid isn’t an antacid. It’s a histamine-2 antagonist (H2 blocker). And it’s available over the counter (OTC) and by prescription.
Pepcid is safe and very well tolerated for most people. But while uncommon, side effects are possible. And it’s good to know what they are and how to manage them.
Pepcid (famotidine) side effects at a glance
Pepcid doesn’t cause side effects for most people who take it. But when side effects do happen, they’re usually mild and can be managed at home. In rare cases, serious issues can happen, so it’s good to know about them before taking the medication.
Mild Pepcid side effects include:
Headache
Dizziness
Constipation
Nausea
Stomach pain
Vomiting
Diarrhea
Taste changes
Rare but serious Pepcid side effects include:
Liver damage
Confusion
Agitation
Seizures
Hallucinations
Below, we’ll cover five Pepcid side effects you should be aware of, along with ways to manage them.
1. Headache
Headaches are a mild Pepcid side effect. In fact, headaches seem to be a potential side effect of all heartburn medications. If you’re taking Pepcid daily, this side effect may be more noticeable when you first start taking it. Usually, headaches go away on their own.
But if you continue having headaches while taking Pepcid, there are several tips that can help you prevent or relieve them. Drinking enough water, exercising regularly, and getting enough rest are good first steps to take.
The right dose: Recommended Pepcid dosages vary depending on why you’re taking it and whether you’re self-treating or following a healthcare professional’s instructions.
OTC relief: Pharmacists review the different OTC medications for heartburn, including Pepcid.
Is it heartburn or something else? Physicians explain what heartburn feels like and when your symptoms may be from something more serious.
If these tips don’t help, ask your healthcare team if you can take an OTC pain reliever such as acetaminophen (Tylenol). It’s best to avoid taking nonsteroidal anti-inflammatory medications (NSAIDs), such as ibuprofen (Advil, Motrin), for headache relief. These can worsen the stomach issues that Pepcid helps treat.
If your headaches are severe or persistent, speak with a healthcare professional. This isn’t typical with Pepcid, and there may be another cause.
2. Dizziness
Dizziness is another mild Pepcid side effect. Because it doesn’t happen very often, this side effect hasn’t been well studied. And experts aren’t sure if certain people have a higher risk than others for dizziness with Pepcid, or if dizziness is more likely to happen with higher Pepcid dosages (greater than 20 mg per day).
While dizziness shouldn’t be severe, any amount of dizziness can raise your risk of falls. So it’s a good idea to take your first dose of Pepcid when you don’t have to drive or perform other activities that require focus. Staying well hydrated may help prevent or limit this Pepcid side effect.
If you begin experiencing dizziness while taking Pepcid, make sure to find a place to sit or lie down to help prevent falls. Getting up slowly when changing positions — such as when going from a seated position to standing up — may also help.
If dizziness continues or worsens, talk to your primary care provider. Long-term or severe dizziness isn’t an expected Pepcid side effect.
3. Stomach-related side effects
Some people taking Pepcid may experience gastrointestinal (GI) side effects. These could include:
Constipation (the most common GI side effect experienced)
Nausea
Stomach pain
Vomiting
Diarrhea
These symptoms should improve or go away as your body gets used to the medication. Stomach pain and nausea can also be symptoms of some of the health conditions Pepcid can treat. So it’s possible the medication isn’t causing them.
For constipation, try slowly increasing your fiber and fluid intake. Exercising regularly may also help get things moving. OTC constipation remedies, such as laxatives and stool softeners, are also options.
If you have diarrhea, make sure to stay hydrated throughout the day. Making diet changes, like avoiding spicy or fatty foods, may help. OTC diarrhea medications, such as loperamide (Imodium A-D), can also be helpful for occasional diarrhea.
If you experience ongoing or severe GI side effects, talk with your primary care provider. They may want to evaluate you for other causes.
4. Liver damage
There have been rare reports of liver damage in people taking Pepcid. When it does happen, this side effect is usually mild, symptom-free, and reversible. But in a few cases, more serious symptoms have happened.
Seek medical help if you experience symptoms of liver damage:
Yellowing of the skin or eyes (jaundice)
Nausea
Dark-colored urine
Right-side stomach pain
Swelling in the stomach
If you currently have liver problems, speak with a healthcare professional before taking Pepcid.
5. Confusion and other brain-related side effects
In rare cases, Pepcid can cause side effects that affect your brain. A few examples include confusion, agitation, and hallucinations. Seizures have also been reported.
People with liver or kidney problems and older adults may have a higher risk of these side effects. The American Geriatrics Society recommends that older adults avoid Pepcid if they have a history of kidney problems or delirium (sudden confusion).
While taking Pepcid, watch for any sudden or unusual changes in your behaviors and thoughts. If you or a loved one notice any changes, contact your primary care provider right away or seek immediate medical attention. If it’s believed that Pepcid is causing these symptoms, they’ll likely have you switch medications.
Frequently asked questions
It’s not recommended for most people to take Pepcid every day long term. Daily Pepcid use can cause acid rebound (returning acid reflux or heartburn) when you stop taking it. But there are health conditions where the benefits of taking it every day outweigh the risks. In general, most people taking OTC Pepcid without a healthcare professional’s guidance shouldn’t take it daily for more than 2 weeks in a row.
If you have a history of kidney problems, check with your primary care provider before taking Pepcid. You may need to take a lower dosage or, in some cases, avoid it. The kidneys help clear Pepcid from the body. If they’re not working as expected, the medication can build up in your body. And this can raise your risk of serious side effects, such as confusion. In particular, those with Zollinger-Ellison syndrome who also have kidney problems should avoid Pepcid due to a risk for side effects.
Pepcid and omeprazole (Prilosec) are both safe for most people when taken for short periods of time. But when it comes to long-term use, Pepcid is likely safer. People taking omeprazole for long periods of time have a greater risk of weakened bones, severe respiratory infections, and low magnesium levels, among other serious side effects. However, omeprazole is usually more effective than Pepcid for treating GERD and other conditions related to too much stomach acid. A healthcare professional can help you decide which option may be better for you.
The bottom line
Mild Pepcid (famotidine) side effects include headaches, dizziness, and stomach-related issues. Usually, these resolve on their own and can be managed at home. Although rare, Pepcid can cause more serious side effects, such as liver damage and brain-related effects.
Talk to a healthcare professional if you experience any bothersome Pepcid side effects. This medication is generally well tolerated, and side effects should go away if you stop taking it. But if you believe you’re experiencing a more serious Pepcid side effect, seek immediate medical attention.
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References
2023 American Geriatrics Society Beers Criteria® Update Expert Panel. (2023). American Geriatrics Society 2023 updated AGS Beers Criteria® for potentially inappropriate medication use in older adults. Journal of the American Geriatrics Society.
National Institute of Diabetes and Digestive and Kidney Diseases. (2018). Famotidine. LiverTox: Clinical and Research Information on Drug-Induced Liver Injury.
National Institute of Diabetes and Digestive and Kidney Diseases. (2019). Acute liver failure. LiverTox: Clinical and Research Information on Drug-Induced Liver Injury.
NCS HealthCare of KY, LLC dba Vangard Labs. (2024). Famotidine- famotidine tablet, film coated [package insert].
Nugent, C., et al. (2024). H2 blockers. StatPearls.
Slavin, M., et al. (2024). Use of acid-suppression therapy and odds of migraine and severe headache in the national health and nutrition examination survey. Neurology Clinical Practice.
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