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Drug vs. Drug

Famotidine vs. omeprazole: Differences, similarities, and which is better for you

Comparing famotidine and omeprazole for treating GERD, ulcers, and heartburn relief. Discover differences in effectiveness, duration, and side effects.
Gerardo Sison medical writer headshot
By | Updated on Oct. 30, 2024 Medically reviewed by Ashley Wong, Pharm. D.
Comparing heartburn medications: Famotidine vs omeprazole

Key takeaways

  • Famotidine and omeprazole are both generic medications used to treat digestive problems, such as gastroesophageal reflux disease (GERD) or a duodenal ulcer. However, they work in different ways.

  • Famotidine tends to work faster than omeprazole, but its effects typically don’t last as long as omeprazole. The dosage of each medication differs as well.

  • While both drugs are effective treatment options for conditions related to excessive stomach acid, omeprazole is considered more potent and longer lasting. But, omeprazole may cause more serious adverse effects, especially if it’s taken long term. Omeprazole also has more drug interactions.

  • It’s best to consult a healthcare provider about which drug is right for you as both medications have potential side effects, precautions, warnings, and drug interactions.

In this article:

Famotidine and omeprazole are medications commonly used to treat a number of digestive problems, such as gastroesophageal reflux disease (GERD) or a duodenal ulcer. These drugs work by decreasing acid production in the stomach. Although they can be found over the counter (OTC), famotidine and omeprazole can also be prescribed by a healthcare provider.

Antacids like Tums (calcium carbonate) are often tried first before starting something stronger, such as an H2 blocker like famotidine or a proton pump inhibitor (PPI) like omeprazole. Fortunately, famotidine and omeprazole are generic medications that are widely available. While they are both acid reducers, they differ in how they work and how they’re used.

What are the main differences between famotidine and omeprazole?

Famotidine

Famotidine is also known by its brand name, Pepcid. It is classified as an H2 blocker. Famotidine works by blocking a protein in stomach cells. This blocks acid from being released into the stomach.

The effects of famotidine can be felt within one hour and can last up to 12 hours. Famotidine tablets are taken once or twice daily, depending on the condition being treated.

Omeprazole

Omeprazole can be purchased as a brand-name drug called Prilosec or Prilosec OTC. Unlike famotidine, omeprazole is classified as a proton pump inhibitor (PPI). It works by directly blocking proton pumps in the lining of the stomach to stop acid production.

Generally, the effects of omeprazole can be felt quickly within one hour after taking it. Its antisecretory effect can last up to 72 hours, which is much longer than that of famotidine. However, the OTC version of omeprazole can take one to four days to reach its full effect. Omeprazole is usually taken once daily.

Main differences between famotidine and omeprazole
  Famotidine Omeprazole
Drug class H2 Blocker Proton Pump Inhibitor (PPI)
Brand/generic status Brand and generic version available Brand and generic version available
What is the brand name? Pepcid Prilosec
What form(s) does the drug come in? Tablet

Tablet, chewable

Powder for oral suspension

Injection

 Capsule, delayed-release

Tablet, delayed-release

Orally disintegrating tablet, delayed-release

Powder for oral suspension

Injection
What is the standard dosage? Duodenal ulcers: 40 mg once daily or 20 mg twice daily for up to 8 weeks

GERD: 20 mg twice daily for up to 6 weeks

Erosive esophagitis: 20- 40 mg twice daily for up to 12 weeks

Dosage depends on the condition being treated

 Duodenal ulcers: 20 mg once daily for up to 4 weeks

GERD: 20 mg once daily for up to 4 weeks

Erosive esophagitis: 20 mg once daily

Dosage depends on the condition being treated
How long is the typical treatment? Up to 6 or 12 weeks or longer  Up to 4 to 8 weeks or longer 
Who typically uses the medication? Adults and certain children Adults and certain children

Conditions treated by famotidine and omeprazole

Famotidine and omeprazole can be prescribed to treat GERD, duodenal ulcers, and stomach ulcers. Both medications are also FDA approved to treat erosive esophagitis (EE), or inflammation of the lining of the esophagus. Erosive esophagitis is often caused by GERD.

Prescription famotidine and omeprazole can also be used to treat hypersecretory conditions, such as Zollinger-Ellison syndrome, systemic mastocytosis, and multiple endocrine adenoma syndrome. Hypersecretory conditions are characterized by excessive acid production that can be temporary or permanent.

Over-the-counter (OTC) versions of famotidine and omeprazole are often used for the relief of occasional or frequent heartburn. 

Omeprazole is also FDA approved to treat Helicobacter pylori, or H. pylori, infections when taken in combination with antibiotics. 

Condition Famotidine Omeprazole
Gastroesophageal reflux disease (GERD) Yes Yes
Duodenal ulcers Yes Yes
Stomach ulcers Yes Yes
Heartburn Yes Yes
Erosive esophagitis Yes Yes
Hypersecretory conditions Yes Yes
H. pylori infection Off-label Yes

Is famotidine or omeprazole more effective?

Both famotidine and omeprazole can be effective drugs for treating GERD and other digestive conditions. However, omeprazole is a more potent and longer-acting drug than famotidine.

One clinical trial directly compared 20 mg of omeprazole once daily to 40 mg of famotidine once nightly in 60 patients with duodenal ulcers. After two to four weeks of treatment, healing rates were higher with omeprazole than with famotidine. Researchers concluded that omeprazole is more effective than famotidine for rapidly healing duodenal ulcers. 

Randomized clinical trials have shown that PPIs are more effective in treating duodenal ulcers than H2 blockers. PPIs were found to significantly increase ulcer healing compared to H2 blockers. No significant differences were found between the PPIs that were studied, which included Prevacid (lansoprazole), Protonix (pantoprazole), and Aciphex (rabeprazole).

In people who take blood thinners, such as clopidogrel and aspirin, a PPI or H2 blocker may be used to prevent stomach bleeding. One systematic review found that PPIs were superior to H2 blockers in preventing bleeding in the stomach. The studies in the review compared PPIs, such as Prilosec (omeprazole) and Nexium (esomeprazole), and H2 blockers, such as Pepcid (famotidine) and Zantac (ranitidine). However, according to its prescribing information, clopidogrel should not be taken with omeprazole or esomeprazole as these drugs can significantly decrease clopidogrel’s effectiveness. 

It’s important to seek medical advice from your healthcare provider before taking famotidine or omeprazole. They can help determine which drug is the best option for you. 

RELATED: Pepcid vs Zantac

Coverage and cost comparison of famotidine vs. omeprazole

Most Medicare Part D plans and other insurance plans will cover generic famotidine tablets. Famotidine can cost an average cash price of around $96 for 60, 20 mg tablets without insurance coverage. If you’re looking to save on the cash price of famotidine, you may be able to use a SingleCare famotidine coupon. With a SingleCare famotidine coupon, you could pay as little as $5 for 60, 20 mg tablets.

Try the SingleCare prescription coupon card

Omeprazole delayed-release capsules are covered by most Medicare and insurance plans. The average retail cost of omeprazole is around $100 for 30, 20 mg capsules. You may be able to use a SingleCare coupon card to lower this cost. With a SingleCare omeprazole coupon, you may be able to reduce the price to around $8, for 30, 20 mg capsules.

  Famotidine Omeprazole
Typically covered by insurance? Yes Yes
Typically covered by Medicare? Yes Yes
Standard dosage 20 mg tablets (quantity of 60) 20 mg capsules (quantity of 30)
Typical Medicare copay $0–$21 $0–$19
SingleCare cost $5 $8

Common side effects of famotidine and omeprazole

The most common side effects of famotidine are headache, dizziness, constipation, and diarrhea. The most common side effects of omeprazole are headache, abdominal pain, diarrhea, flatulence, nausea, and vomiting. Omeprazole may be more likely than famotidine to cause certain gastrointestinal side effects, such as flatulence or gas.

Serious side effects include allergic reactions to any of the ingredients in these medications. Allergic reactions can include rash or trouble breathing. Seek medical attention if you experience serious adverse effects.

  Famotidine Omeprazole
Side Effect Applicable? Frequency Applicable? Frequency
Headache Yes ≥1% Yes 7%
Dizziness Yes ≥1% Yes 2%
Constipation Yes ≥1% Yes 2%
Diarrhea Yes ≥1% Yes 4%
Stomach ache Yes <1% Yes 5%
Nausea Yes <1% Yes 4%
Vomiting Yes <1% Yes 3%
Flatulence No – Yes 3%

This may not be a complete list. Consult your doctor or pharmacist for possible side effects.

Source: DailyMed (famotidine), DailyMed (omeprazole)

Drug interactions of famotidine vs. omeprazole

Famotidine and omeprazole may need to be avoided with drugs that depend on stomach acid for absorption. These drugs include certain cancer drugs, such as Tarceva (erlotinib) and Tasigna (nilotinib), and antifungals, such as ketoconazole and itraconazole. Taking famotidine or omeprazole can decrease the absorption of these drugs and decrease their overall effectiveness.

Famotidine can also interact with tizanidine, a muscle relaxer that is broken down by the CYP1A2 enzyme in the liver. Famotidine can increase levels of tizanidine in the body, which can lead to low blood pressure (hypotension), slow heartbeat (bradycardia), or extreme drowsiness.

Omeprazole can interact with several drugs. Certain drugs may slow the break down of omeprazole in the body, which increases its levels in your system. These include Vfend (voriconazole) and Cardizem (diltiazem). Other drugs can speed up omeprazole’s break down in your body, which reduces its levels in your system. Examples include Rifadin (rifampin) and Norvir (ritonavir). Omeprazole may also interact with other drugs, such as Coumadin (warfarin), Trexall (methotrexate), and Celexa (citalopram). 

Famotidine and omeprazole may interact with other drugs not described here. It is important to tell your healthcare provider about all medications you take before starting treatment with famotidine or omeprazole. 

Drug Drug Class Famotidine Omeprazole
Atazanavir

Rilpivirine

Nelfinavir

Ledipasvir/sofosbuvir

Fosamprenavir

 Antiretrovirals Yes Yes
Erlotinib

Dasatinib

 Chemotherapy Yes Yes
Ketoconazole

Itraconazole

 Antifungal Yes Yes
Tizanidine Muscle relaxer Yes No
Tacrolimus

Methotrexate

 Immunosuppressant No Yes
Warfarin Anticoagulant No Yes
Rifampin Antibiotic No Yes

This may not be a complete list of all possible drug interactions. Consult a doctor about all the medications you may be taking.

Warnings of famotidine and omeprazole

Severe GERD symptoms or ulcers may be a sign of gastrointestinal cancer in some people. Additional testing and monitoring may be needed for people who don’t respond to treatment with a PPI or H2 blocker.

Famotidine should be used with caution in elderly people or those with kidney problems, as the drug can reach higher levels in the body in these populations.. As a result, these people may be at higher risk of side effects of famotidine. 

Unlike famotidine, omeprazole and other PPIs can increase the risk of osteoporosis and bone fractures when used long-term. In addition, omeprazole use, especially in a hospital setting, may lead to an increased risk of Clostridium difficile-related diarrhea. One study found that proton pump inhibitors are associated with greater risks of serious adverse effects, like pneumonia and C. diff infections, when compared to H2 blockers in critically ill patients. 

Overall, omeprazole tends to have more warnings and precautions associated with it compared to famotidine. Consult a healthcare provider about other possible safety concerns with H2 blockers and PPIs. 

Frequently asked questions about famotidine vs. omeprazole

Are famotidine and omeprazole the same?

Famotidine and omeprazole are not the same. Although they treat similar gastrointestinal problems, they are different drugs. Famotidine is an H2 blocker and omeprazole is a PPI.

Is famotidine or omeprazole better?

Omeprazole is considered to be more potent than famotidine. The effects of omeprazole also last longer than the effects of famotidine.However, omeprazole may have more serious adverse effects associated with its use, such as an increased risk of osteoporosis and C.diff diarrhea with long-term use.

Can I take omeprazole and famotidine together?

There are no drug interactions between omeprazole and famotidine, and each works differently to decrease stomach acid. In most cases, one medication is enough to provide reflief. But, there are some situations where your healthcare provider may prescribe these drugs together. 

One study found that combining famotidine and omeprazole was more effective for acid control than famotidine or omeprazole alone. Researchers concluded that the long-acting effects of omeprazole could be complementary to the relatively fast-acting effects of famotidine. Still, more studies are needed to determine whether combining omeprazole and famotidine is appropriate. 

Can I use famotidine or omeprazole while pregnant?

It’s not known whether famotidine or omeprazole are safe to take during pregnancy. . Consult your healthcare provider when choosing a treatment option while pregnant or breastfeeding.

Can I use famotidine or omeprazole with alcohol?

Alcohol does not interact with the way famotidine and omeprazole work. However, alcohol may increase the risk of acid reflux symptoms. It’s best to limit yourself to drinking alcohol in moderation or avoiding alcohol altogether, especially if you notice an increase in symptoms or side effects.

What is the safest heartburn medication to take long term?

It depends. Each medication has its own risks, however, omeprazole can cause more long-term adverse effects in comparison to famotidine. These include osteoporosis, low vitamin B-12 and magnesium levels, and fundic gland polyps (a type of noncancerous growth in the stomach). For this reason, omeprazole is typically only taken for 4 to 8 weeks. In addition, omeprazole has more potential drug interactions than famotidine. Therefore, it’s best to talk to your healthcare provider about which drug is safest for you. They can weigh the potential risks and benefits of each medication and take into account your medical history and current medications. 

Is it ok to take Pepcid every day?

Pepcid is typically taken on a daily basis for up to12 weeks at a time. The duration of treatment depends on the condition that is being treated. Talk to your doctor to find out how long you should be taking Pepcid. Consider lifestyle changes in addition to medications to help relieve heartburn that occurs more frequently.

What is the fastest-acting heartburn medicine?

Antacids usually work the fastest for treating heartburn symptoms. Antacids like Tums (calcium carbonate) can neutralize acid within 30 minutes of taking them. Compared to famotidine, calcium carbonate was found to have a faster onset of action. While they give quick relief of heartburn, antacid effects do not last for the whole day. H2 blockers and PPIs last longer and are reserved for more chronic digestive conditions like GERD.

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