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Compare Famotidine vs. Omeprazole

Head-to-head comparisons of medication uses, side effects, warnings, and more.

Key takeaways

Famotidine (Pepcid AC) and omeprazole (Prilosec) are both used to treat conditions related to excess stomach acid, but they work differently. Famotidine is a histamine-2 (H2) antagonist that lowers stomach acid by blocking histamine receptors in the stomach lining. It starts working within an hour and is taken twice daily. Omeprazole, on the other hand, is a proton pump inhibitor (PPI) that blocks the final step of acid production in the stomach and is typically taken once daily before breakfast. Famotidine is available both over-the-counter and by prescription, while omeprazole is also available in both forms. Common side effects of famotidine include headache, dizziness, and constipation, whereas omeprazole can cause headache, stomach pain, and nausea. Omeprazole is generally preferred for conditions like erosive esophagitis due to its more effective and longer-lasting relief, but it takes longer to start working compared to famotidine.

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Famotidine Vs. Omeprazole: Which Works Best For GERD?

Famotidine (Pepcid AC)
Omeprazole (Prilosec)
Famotidine (Pepcid AC)
Omeprazole (Prilosec)
Summary of Famotidine vs. Omeprazole
Summary for Histamine H2 antagonist
Famotidine (Pepcid AC) is a histamine-2 (H2) antagonist that's used to treat conditions that cause too much stomach acid to build up, such as heartburn and stomach or intestinal ulcers (sores). It starts to work within an hour and lasts for several hours. It's available as a tablet and a liquid, and is taken by mouth twice per day. Side effects of famotidine (Pepcid AC) include headache, dizziness, and constipation.
Summary for PPI
Omeprazole (Prilosec) is a proton pump inhibitor (PPI). Over-the-counter (OTC) omeprazole (Prilosec) can ease heartburn, while the prescription version can treat gastroesophageal reflux disease (GERD) and other conditions involving too much stomach acid. Omeprazole (Prilosec) is taken by mouth, typically once daily 30 minutes before breakfast. Some of the more common side effects of omeprazole (Prilosec) include headache, stomach pain, and nausea. It's available as both brand name and generic medications.
Indications of Famotidine vs. Omeprazole
Indications for
Over-the-counter (OTC) famotidine

•Prevention and treatment of heartburn (gastroesophageal reflux disease or GERD)

Prescription famotidine

•Gastric ulcer (open sore in the stomach)

•Duodenal ulcer (open sore in the first part of the small intestine)

•Heartburn (GERD)

•Erosive esophagitis due to GERD (inflammation of the esophagus)

•Other conditions that cause too much stomach acid secretion (i.e., Zollinger-Ellison syndrome)

Indications for
For adults only:

•Heartburn — OTC only

•Stomach or duodenal ulcer

•Lower the risk of duodenal ulcer caused by Helicobacter pylori (H. pylori) infection

•Other medical conditions that cause too much stomach acid (e.g., Zollinger-Ellison syndrome)

For adults and children:

•Gastroesophageal reflux disease (GERD)

•Inflamed esophagus due to GERD
Pros and Cons of Famotidine vs. Omeprazole
Pros and Const for Histamine H2 antagonist
Pros

•Starts to work within an hour and lasts for up several hours

•Available as both a generic and over-the-counter option

•If needed, can be used with some other acid-lowering medications, such as antacids (e.g., calcium carbonate (Tums)) or PPIs

•Generally well-tolerated with little side effects

•Available as a oral suspension, a good option for people who can't swallow tablets

Cons

•Antacids start to work more quickly than famotidine (Pepcid AC)

•PPIs work better at healing and preventing stomach ulcers than famotidine (Pepcid AC).

•Needs to be taken twice daily for most conditions

•Not the best option for people with kidney problems

Pros and Const for PPI
Pros

•Typically few to no noticeable day-to-day side effects

•Provides longer-lasting relief than some other heartburn medications

•Can use for adults, as well as children with certain medical conditions

•Available as over-the-counter and lower-cost generic options

Cons

•Interacts with many medications, such as digoxin (Lanoxin) and clopidogrel (Plavix)

•Won't provide immediate heartburn relief

•Usually taken 30 to 60 minutes before eating a meal for best results

•Not recommended for long-term treatment, except for certain conditions, because of risk of serious side effects
Common Side Effects of Famotidine vs. Omeprazole
Common Side Effects for

•Headache

•Dizziness

•Constipation

•Diarrhea

Common Side Effects for
Adults

•Headache (7%)

•Belly pain (5%)

•Nausea (4%)

•Diarrhea (4%)

•Vomiting (3%)

•Passing gas (3%)

Children — similar to the above, with the addition of:

•Respiratory system problems (up to 75%)

•Fever (up to 33%)

•Ear infection (up to 22%)
Warnings of Famotidine vs. Omeprazole
Common Side Effects for

•Agitation, confusion, and other brain-related side effects

•Possible risk of cancer

Common Side Effects for

•Risk of hiding symptoms of a more serious problem

•Sudden kidney problems

•Severe infectious diarrhea

•Bone fractures

•Skin reactions

•Lupus

•Low vitamin B12 and magnesium levels

•Interaction with other medications

•Inaccurate lab work
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Key takeaways

Summary of Famotidine vs. Omeprazole

Indications of Famotidine vs. Omeprazole

Pros and Cons of Famotidine vs. Omeprazole

Common Side Effects of Famotidine vs. Omeprazole

Warnings of Famotidine vs. Omeprazole

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