Compare Omeprazole vs. Alka-Seltzer

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

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Alka-Seltzer Original
(Aspirin / Citric Acid / Sodium Bicarbonate)

Treats heartburn and stomach ulcers. Prilosec (Omeprazole) gives you long-lasting heartburn relief. Choose the cheapest proton pump inhibitor because they all work equally well for heartburn.Relieves heartburn, headache, and body pains. Alka-Seltzer Original (Aspirin / Citric Acid / Sodium Bicarbonate) gives quick relief for headache, body pains, and upset tummies, but might be hard to swallow if you don't like the taste or fizz.
How it works
Prilosec (Omeprazole) is a proton pump inhibitor (PPI). It lowers the amount of acid in your stomach, treats heartburn, and heals ulcers.Alka-Seltzer Original (Aspirin / Citric Acid / Sodium Bicarbonate) is a combination medicine. Sodium bicarbonate is an antacid that relieves heartburn and acid tummy (indigestion). Aspirin is a pain reliever that treats headache and body pains.
Type of medication
Acid reducer
Proton pump inhibitor
Prescription or OTC
Available as
  • Extended release
  • Chewable tablet
  • Effervescent tablet
Used for (click to learn more)
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Reviews & ratings
Button Group. All currently active
Button Group. All currently active
Reviews for Prilosec (Omeprazole)
of people say Prilosec (Omeprazole) is worth it
say it works well
say it's a big hassle
Reviews for Alka-Seltzer Original (Aspirin / Citric Acid / Sodium Bicarbonate)
+1% vs. Prilosec (Omeprazole)
7% vs. Prilosec (Omeprazole)
1% vs. Prilosec (Omeprazole)
Side effects

The Omeprazole FDA package insert doesn’t have numbers about how common side effects are.

More about Omeprazole side effects »

We haven’t found good data for Alka-Seltzer side effects.

FDA side effect reports for Alka-Seltzer »
Risk factors for serious side effects
    • Helicobacter pylori infection
    • Autoimmune disease
    • Being hospitalized
    • Antibiotic use
    • Osteoporosis
    • Age 50 or older
    • Using high medication doses
    • Long-term therapy (1 year or more)
    • Smoking
    • Use of other medications that weaken bones
      Detailed Prilosec (Omeprazole) risks & warnings »
        • Current kidney disease
        • Kidney dialysis
        • Age 65 or older
        • Congestive heart failure (CHF)
        • High blood pressure
        • Current kidney disease
        • Kidney dialysis
        • Children 18 years or younger recovering from viral infections
        • History of stomach bleeding or ulcers
        • Age 60 or older
        • Also taking other blood thinners
        • Drinking 3 or more alcoholic drinks a day
        • Asthma
        • Rhinitis
        • Nasal Polyps
        • Aspirin Allergy
        • NSAID Allergy
          Detailed Alka-Seltzer Original (Aspirin / Citric Acid / Sodium Bicarbonate) risks & warnings »
          Pregnancy category
          CFDA pregnancy category (Weigh risks vs. benefits)

          Research studies with animals found harmful effects on unborn babies. It hasn’t been properly studied in humans. The benefits might outweigh the risks even if you’re pregnant. Talk with your doctor.

          See the FDA package insert
          NFDA pregnancy category (Unknown)

          The FDA hasn’t classified this medicine’s effects on unborn babies. Talk with your doctor about this medicine if you’re pregnant or planning on it.

          See the FDA package insert
          No specific alcohol-related info.No specific alcohol-related info.
          • Take 1 hour before a meal.
          • Take it with food to lower the chance of an upset stomach.
          Kidneys and liver
          No specific kidneys and liver-related info.
          • If you have kidney or hyperparathyroid disease Alka-Seltzer Original (Aspirin / Citric Acid / Sodium Bicarbonate) can build up in your blood. This may can cause toxic levels of sodium in your body. This is more likely if you have severe kidney disease (defined as a kidney function blood test called GFR of less than 30ml/min). If you have severe kidney disease or are on kidney dialysis don't use Alka-Seltzer Original (Aspirin / Citric Acid / Sodium Bicarbonate); a different antacid would be better for you.
          • Alka-Seltzer Original (Aspirin / Citric Acid / Sodium Bicarbonate) contains sodium. Sodium can raise blood pressure and cause your body to hold on to water. If you have high blood pressure, heart failure, or kidney disease you should not take Alka-Seltzer Original (Aspirin / Citric Acid / Sodium Bicarbonate).
          No specific sex-related info.No specific sex-related info.
          No specific sleep-related info.No specific sleep-related info.
          No specific weight-related info.No specific weight-related info.
          Upsides and benefits
          • Most people can take Omeprazole without any noticeable day-to-day side effects.
          • Omeprazole lasts longer than other types of antacids (like Zantac, Pepcid, or Tums), and you only need to take it once or twice a day.
          • You can take it in combination with a quick-acting antacid (like Maalox or Tums) if you need relief right away.
          • In studies it was better than a placebo (sugar pill) and as good as other proton pump inhibitors at treating heartburn.
          • Available as both a generic and over-the-counter option, so it's pretty affordable.
          • Works great if you have an upset stomach and a headache or body pain at the same time.
          • Works really fast.
          • Available over the counter without a prescription.
          • Cheap.
          Downsides and risks
          • Doesn't start working as fast as some other antacids like Tums, Rolaids, or Maalox.
          • Like with other proton pump inhibitors, long-term use can cause weak or broken bones.
          • Can cause low levels of magnesium in the blood. You might need to take a magnesium supplement if you use Omeprazole long-term.
          • Although the generic is affordable, other medications might still be cheaper than Omeprazole.
          • Can interact with other drugs so be sure your doctor knows all the medicine you're taking before starting Omeprazole.
          • Doesn't last very long.
          • Other antacids like Zantac (H2 blockers) and omeprazole (proton pump inhibitors) can work better and last longer.
          • Because it has aspirin in it, it increases the risk of bleeding, especially if you take any other blood thinning medicine.
          • Can't be used by people with allergy to aspirin.
          • You may not like the taste or fizz.
          Tips from our pharmacists for people taking the medication
          • Take 1 hour before a meal.
          • Don't chew or crush capsules; swallow them whole.
          • If you have trouble swallowing you can carefully open the capsules and sprinkle the inside pellets onto applesauce. Swallow the applesauce without chewing or crushing the pellets.
          • When using Omeprazole long-term, take a calcium citrate with vitamin D supplement daily to prevent bone loss. Be sure it's calcium citrate because it works the best when using a proton pump inhibitor.
          • Get a blood test for your magnesium level once a year; you may need a magnesium supplement while using Omeprazole.
          • Avoid drug interactions by telling your doctor all of the other medications or herbal supplements you take before starting Omeprazole.
          • Don't take Alka-Seltzer if you're allergic to aspirin.
          • Take it with food to lower the chance of an upset stomach.
          • This medicine isn't recommended for kids 12 and younger because it has aspirin in it.
          • Stop taking this right away and talk to your doctor if you have ringing in your ears, rash, trouble breathing, unusual bleeding, or nausea or vomiting that doesn't go away.
          • Having a dental or medical procedure? You may need to stop taking this before the big day. Ask your dentist or doctor.
          • Alka-Seltzer contains sodium. If you need to follow a low sodium diet a different medication would be better for you.
          • Not a good choice if you have stomach bleeding, bleeding problems, diabetes, or gout, or if you're taking medicines to thin your blood.
          Learn more
          More about OmeprazoleSide effectsReviews & ratingsAlternativesFDA package insert
          More about Alka-SeltzerSide effectsReviews & ratingsAlternativesFDA package insert