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Aug 23, 2022

Gut Health

Choosing the Right Acid Reflux Medication: Dive into the Famotidine vs. Omeprazole Debate

Both famotidine and omeprazole are used to treat acid-related digestive issues such as GERD, erosive esophagitis, stomach & duodenal ulcers and hypersecretory conditions. Although they are both stomach acid reducers, they differ in how they work and how they are used. In this article we will compare them side by side to help you make informed decisions when you talk with your healthcare provider.

What is Famotidine For?

Famotidine is prescribed for digestive system issues, such as:

  • Short-term treatment of GERD
  • Long-term maintenance prevention of duodenal ulcers
  • Short-term treatment of a duodenal ulcer
  • Short-term treatment of a gastric ulcer
  • Long-term treatment of hypersecretory conditions

How Does Famotidine Work?

Famotidine is a type of medication called a histamine-2 receptor antagonist (H2RA). H2 blockers work in the same way that their name describes: histamine, a chemical in your body, binds to a receptor, the place where histamine attaches to send a signal, and acts as an antagonist, blocking or stopping a signal.

In a normal situation, when you eat food, your body releases histamine which communicates with a special stomach cell telling it to make stomach acid. Famotidine binds to the same receptor on this special cell, but instead of sending a signal to make acid, it blocks the signal to make acid and less acid is released into the stomach.

Read our blog about Famotidine

What is Omeprazole For?

Omeprazole is a different kind of medication called a proton-pump inhibitor (PPI). Omeprazole is indicated to treat:

  • Short-term treatment of GERD
  • Long-term maintenance prevention of erosive esophagitis
  • Short-term treatment of a duodenal ulcer
  • Short-term treatment of a stomach ulcers
  • Long-term treatment of hypersecretory conditions

While this list looks very similar to the famotidine indications, you can see the difference in list number 2, where famotidine is used as ulcer prevention, and not erosive esophagitis. Omeprazole then treats erosive esophagitis but is not indicated to prevent duodenal ulcers.

Read our blog about Omeprazole

How Does Omeprazole Work?

Omeprazole is a PPI (Proton Pump Inhibitor). Stomach acid is produced by a ‘pump’ in your stomach. PPIs work by stopping this pump and this results in your body producing less stomach acid.

Omeprazole (PPI) vs. Famotidine (H2RA)

Both PPIs and H2RAs reduce the amount of stomach acid your body produces. However, they achieve this by two different mechanisms.

H2RAs (H2 blockers) block stomach acid production at an ‘earlier’ stage in the stomach acid process, by blocking histamine’s ability to tell your stomach to make acid, whereas PPIs stop the pump that usually releases acid into the stomach (one of the final steps).

Famotidine vs. Amlodipine

H2 blockers (H2RAs) reduce acid production by blocking histamine from binding to the histamine 2 receptor. This happens at an earlier stage of acid production.

PPIs block the proton pump from pumping acid into the stomach. One of the final steps of acid production.

Comparing Side Effects

Both medications have some possible side effects, though not every patient will experience any or all of these side effects. However, it’s good to know what you may experience while on either medication. Famotidine has slightly fewer common side effects, but every patient responds differently to either medication, so this is not definite.

Famotidine (H2 blocker) Omeprazole (PPI)
  • Diarrhea
  • Constipation
  • Headache
  • Dizziness
  • Diarrhea
  • Constipation
  • Headache
  • Abdominal pain
  • Nausea & vomiting
  • Flatulence (gas)

Which One Should I Be On?

This question is best answered by your healthcare provider. However, there are a number of things to consider, which are outlined here.

Famotidine Omeprazole
Used for
  1. GERD
  2. Prevention of duodenal ulcer(s)
  3. Duodenal ulcer(s)
  4. Gastric ulcer(s)
  5. Hypersecretory conditions
  1. GERD
  2. Prevention of erosive esophagitis
  3. Duodenal ulcer(s)
  4. Gastric ulcer(s)
  5. Hypersecretory conditions
Short-term effectiveness
Very effective Very effective
Long-term effectiveness
Less effective Very effective
Side effects
Rare, fewer side effects Rare, more possible side effects
Long-term use
It's likely safe to take long-term There are some safety risks when taking long-term
For nursing or pregnant women
Not well studied—likely safe, potentially safer than omeprazole. Not well studied, potentially safe.
Can children take it?
Yes, but there may be an increased risk of infection. Yes
Drug-drug interactions
There are no major interactions with other medications. Maybe. There are many medications that you should not be taking while on omeprazole.
Cost at Marley Drug
$70 for a 12-month supply
$37 for a 6-month supply
$70 for a 12-month supply
$37 for a 6-month supply

Effectiveness and Risks of Taking Omeprazole vs. Famotidine Long-term

See the long-terms risks of taking PPIs

The long-term risks for famotidine and omeprazole have been studied but are not extensive. The risks associated with being on PPIs such as omeprazole long-term are more concrete than the risks of being on famotidine long-term.

The most concrete possible risks of being on omeprazole long-term are vitamin and mineral deficiencies. Since PPIs are effective long-term, they cause long-term reduction of the amount of acid in your stomach. While this is great for treating many conditions, it can also lead to health risks. Vitamins and minerals such as vitamin B12, calcium, and magnesium, require acid to be released from food and/or absorbed into our bodies. Because of this, suppressing the acid for a long time with PPIs can lead to less of these vitamins and minerals getting into our bodies and we can develop deficiencies. There are ways to treat these deficiencies, by greatly increasing the amount of these vitamins and minerals you consume, but it’s also worth re-evaluating if you need to be on PPIs for so long that this develops.

There are also a number of other possible risks involved with taking PPIs long-term including kidney issues, increased risk of ulcers, C. difficile infections, and gastric cancer. However, the links between these conditions and PPIs have not been studied well enough at this point to form conclusive links between these conditions and PPI use.

H2RAs are not thought to have the same risks, or at least not as great of a risk for developing these conditions from long-term H2RA use. Why is that? The most probable reason is because H2RAs don’t actually work very well long-term. People taking H2RAs, like famotidine, develop something called “tolerance”. This is when your body essentially gets used to what the drug is doing and starts making up for it. In the case of famotidine, your body notices that your acid is being suppressed so it starts making up for it by making more acid. It’s not conclusive how this actually happens, but it has been well documented that it does happen relatively quickly after being on H2RAs.

What if I am Pregnant or Breastfeeding?

Many medications have not been well studied in pregnant and/or breastfeeding women, due to the safety concerns of studying possibly unsafe medications in these women and the possible dangers to their infants. Because of this, it’s often recommended that pregnant and/or breastfeeding women avoid some medications when possible, and try to treat certain conditions, like GERD, with lifestyle modifications before switching to medications.

Famotidine is technically safe for use while pregnant, though there aren’t many human studies that have fully evaluated the safety. Because of this, it’s usually recommended to limit use of famotidine while pregnant. If you are taking famotidine and become pregnant your healthcare provider may weigh the pros and cons of keeping you on famotidine and decide it’s in your best interest to keep taking it. Famotidine is also generally avoided while breastfeeding, since it does get into the breastmilk. It’s not likely a high enough concentration to negatively affect the baby, but this is also not well studied.

Similarly, the safety of Omeprazole has not been fully studied in pregnant women. It’s not shown to be safe in pregnant animals, but the transfer of that to humans isn’t always consistent. However, because of this it’s also generally recommended to avoid using omeprazole while pregnant. Omeprazole gets into the breastmilk and since it’s difficult to know exactly how much of the medication the newborn is getting through the breastmilk, it is recommended to avoid omeprazole if breastfeeding.

For pregnant and/or breastfeeding women, it is generally recommended to avoid the use of either omeprazole or famotidine. However, your healthcare provider may decide that the possible risks are less substantial than the benefits of being on the medication and may choose to keep you on either medication. In this case, famotidine is usually preferred since it may have a slightly better safety profile.

Are They Safe for Children?

Omeprazole has been indicated for use in children as young as 1 month old for various conditions, such as GERD. It has been deemed both safe and effective for children.

Famotidine has also been proven safe and effective for use in children. However, use of H2RAs in children aged 4–36 months has been associated with an increased risk of developing pneumonia and gastroenteritis (infection in your digestive system). Because of this, it may be best to avoid famotidine in children aged 4–36 months.

Which is Better If I am on Other Medication?

Famotidine has no major contraindications with other medications. Omeprazole, however, has many interactions with medications including HIV medications, clopidogrel, methotrexate, and certain antibiotics. Because of this, it may be safer for you to take famotidine if you are on many medications.

Regardless, it’s important for you to make your healthcare provider aware of any prescription medications, over-the-counter medications, natural health products, and supplements you may be taking in case they interact with a medication you’re taking.

Omeprazole and Famotidine Price

The cost of famotidine and omeprazole can vary based on the pharmacy and the dosage you’ve been prescribed. However, at Marley Drug you can get famotidine and omeprazole for the same price. This price doesn’t change no matter which strength or dosing frequency you’ve been prescribed.

Both omeprazole and famotidine are part of our Wholesale Price List. This means that you can get a 6-month supply for $37 or a full 12-month supply for $70. This price still doesn’t change even if you are prescribed 2 pills per day. Shipping is also free for 6- and 12- month supplies, so there are no extra additional charges.

This is great because sometimes people will be on a medication that works well for them but have to change to another medication like from an H2RA to a PPI, or vice versa, because of cost. With our Marley Drug Wholesale Price List, you can stay on one medication and don’t have to worry about cost changes or sacrificing your wellbeing by switching to a cheaper alternative


If you aren’t sure what medication you should take be sure to talk with your healthcare provider or one of our pharmacists: Dee, Jon and Chris, who would be happy to help answer any questions you have. To speak with a pharmacist please give us a call at 1-800-810-7790.

  1. Prilosec (omeprazole) – Access data FDA-Approved Drugs [Internet]. [amended 09/2012; accessed 06/2022].
  2. Koyyada, A. (2021). Long-term use of proton pump inhibitors as a risk factor for various adverse manifestations. Therapies, 76(1), 13-21. doi: 10.1016/j.therap.2020.06.019
  3. Pepcid (famotidine) – Access data FDA-Approved Drugs [Internet]. 1986 [amended 06/2011; accessed 06/2022].
  4. Zhang, Y. (2015). Proton pump inhibitors therapy vs H2 receptor antagonists therapy for upper gastrointestinal bleeding after endoscopy: A meta-analysis. World Journal Of Gastroenterology, 21(20), 6341. doi: 10.3748/wjg.v21.i20.6341

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