Compare Tagamet vs. omeprazole

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

Tagamet (cimetidine)

Prescription or OTC

Prilosec (omeprazole)

Prescription or OTC
Treats heartburn.

Tagamet (cimetidine) works well for heartburn, but may have more side effects than other medicines like it.

3.4/ 5 average rating with 632 reviewsforTagamet
Treats heartburn and excess release of stomach acid.

Prilosec (omeprazole) gives you long-lasting heartburn relief but has some risks if used long term.

4.0/ 5 average rating with 1167 reviewsforomeprazole
  • Lasts longer than other medicines like it so you may not need to take it as frequently.
  • Affordable as an over-the-counter or generic medicine.
  • Prilosec (omeprazole) lasts longer (up to 72 hours) than other classes of acid reducers (like Zantac, Pepcid, or Tums).
  • Only take once or twice daily.
  • Can take together with a quick-acting antacid (like Maalox or Tums) for quick relief.
  • Generic and over-the-counter options available.
  • Safe to use in children ages 1 or older.
  • Does not work as fast as antacids like Maalox, Tums, or Rolaids.
  • May not work as well if you have an inflammed esophagus. Your doctor will assess which medicine is best for you.
  • May not be the best option if you are elderly or have kidney or liver problems.
  • Can interfere with how other medicines work.
  • Takes up to an hour to start noticing the effects of Prilosec (omeprazole).
  • Prilosec (omeprazole) can interact with other drugs. Let your doctor and pharmacist know what medications you're taking before starting Prilosec (omeprazole).
  • Long-term use of Prilosec (omeprazole) can put you at risk for many health issues such as osteoporosis, low magnesium or vitamin B12 levels, and rebound acid secretion (where your body starts to create more acid than before after stoping Prilosec (omeprazole)).
Used for
Dosage forms
  • Pill
  • Liquid
  • Pill
  • Powder
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632 reviews so far
saidit'sworth it
saiditworked well
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Have you used Tagamet (cimetidine)?

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1167 reviews so far
saidit'sworth it
saiditworked well
saidit'sa big hassle

Have you used Prilosec (omeprazole)?

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Side effects
The Tagamet (cimetidine) FDA package insert doesn’t have numbers about how common side effects are.
11possible side effects
  • Headache
  • Abdominal pain
  • Nausea
  • Diarrhea
  • Vomiting
  • Flatulence
  • Acid regurgitation
  • Upper respiratory infection
  • Constipation
  • Dizziness
  • Rash
See more detailed side effects
Risks and risk factors
  • Confusion
    • Elderly
    • Kidney problems
    • Liver problems
    • Dementia
  • Drug interactions
  • Chronic lung problems
    • Asthma
    • COPD
    • Lung problems
  • Clostridium difficile associated diarrhea
    • Taking antibiotics
  • Englarged breasts in men (gynecomastia)
See more detailed risks and warnings
  • Risk of cancer
  • Lupus
    • History of cutaneous or systemic lupus erythematosus
  • Severe diarrhea associated with C.difficile infection
    • Being hospitalized
    • Antibiotic use
  • Bone fractures
    • Osteoporosis
    • Using high medication doses
    • Long-term therapy (1 year or more)
    • Use of other medications that weaken bones
  • Low Vitamin B12 and Magnesium
    • Taking water pills (Magnesium)
    • Women (Vitamin B12)
    • Over the age of 30 (Vitamin B12)
  • Kidney damage
See more detailed risks and warnings