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Prevacid vs. Prilosec: Differences, similarities, and which is better for you

Drug overview & main differences | Conditions treated | Efficacy | Insurance coverage and cost comparison | Side effects | Drug interactions | Warnings | FAQ

If you have GERD (gastroesophageal reflux disease) or a stomach ulcer, your healthcare provider may suggest a PPI (proton pump inhibitor). Prevacid (lansoprazole) and Prilosec (omeprazole) are in a drug class called proton pump inhibitors and are indicated for the treatment of GERD and other gastrointestinal conditions. Proton pump inhibitors work by blocking and reducing the production of stomach acid and preventing heartburn. Although both medications are known as PPIs, they do have some differences in indications, costs, and side effects.

What are the main differences between Prevacid and Prilosec?

Prevacid (lansoprazole) and Prilosec (omeprazole) are both in the proton pump inhibitor class of drugs. Both medications are available in brand-name and generic, and both are available in prescription and over-the-counter (OTC). The dosage varies by indication. A typical dose of prescription Prevacid is 30 mg once or twice daily, and a typical dose of Prilosec is 20 mg once or twice daily.

Main differences between Prevacid and Prilosec
Prevacid Prilosec
Drug class Proton pump inhibitor Proton pump inhibitor
Brand/generic status Brand and generic Brand and generic
What is the generic name? Lansoprazole Omeprazole
What forms does the drug come in? Rx: delayed-release capsules, soluble tablets
OTC: delayed-release capsules
Rx: delayed-release capsules, suspension
OTC: delayed-release
What is the standard dosage? Varies by indication: usually 15-30 mg once or twice daily Varies by indication: usually 20-40 mg once or twice daily
How long is the typical treatment? 10 days to 12 weeks, many patients take for longer 10 days to 8 weeks, many patients take for longer
Who typically uses the medication? Adults; children 1 year and older Adults; children 2 years and older

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Conditions treated by Prevacid and Prilosec

Both medications have several indications for treatment. Prevacid and Prilosec (What is Prilosec?) are indicated for the treatment of active duodenal ulcer, the eradication of H. pylori, treatment of active benign gastric ulcer, Zollinger-Ellison syndrome, and GERD. Some additional indications for Prevacid (What is Prevacid?) include maintenance of healed duodenal ulcers, healing and risk reduction of NSAID associated gastric ulcer, and the treatment and maintenance of healing of erosive esophagitis (EE). Some additional indications for Prilosec include treatment of EE due to acid-mediated GERD and maintenance of healing of EE due to acid-mediated GERD.

Condition Prevacid Prilosec
Treatment of active duodenal ulcer Yes Yes
Eradication of H. pylori to reduce the risk of duodenal ulcer recurrence – used in combination with one or two antibiotic(s) Yes Yes
Maintenance of healed duodenal ulcers Yes No
Treatment of active benign gastric ulcer Yes Yes
Healing of NSAID-associated gastric ulcer Yes No
Risk reduction of NSAID-associated gastric ulcer Yes No
Treatment of symptomatic gastroesophageal reflux disease (GERD) Yes Yes
Treatment of erosive esophagitis (EE) Yes No
Treatment of EE Due to acid-mediated GERD No Yes
Maintenance of healing of EE Yes No
Maintenance of healing of EE due to acid-mediated GERD No Yes
Pathological hypersecretory conditions including Zollinger-Ellison Syndrome (ZES) Yes Yes

Is Prevacid or Prilosec more effective?

In a double-blind study of 3510 patients, comparing Prevacid to Prilosec for heartburn relief, patients received either Prevacid 30 mg daily for eight weeks, or Prilosec 20 mg daily for eight weeks. Both drugs were well-tolerated. The patients treated with Prevacid had less severe heartburn symptoms, and more heartburn-free days and nights. The difference between medications, though, was small and narrowed by the end of eight weeks.

In a meta-analysis study (looking at many studies) of the efficacy of PPIs for short-term use, the authors concluded that all the PPIs were comparable, and using an effective dose of PPI was more important than which PPI was used.

A study in the American Journal of Gastroenterology concluded that patients who obtained a prescription PPI from a gastroenterologist were more likely to be compliant in taking their medications, and as a result, have better symptom control, as opposed to patients who purchased over-the-counter PPIs.

The most effective medication should only be determined by your doctor, who can take into account your medical condition(s), history, and other medications you are taking that could interact with Prevacid or Prilosec.

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Coverage and cost comparison of Prevacid vs. Prilosec

Both Prevacid and Prilosec are usually covered by insurance as well as Medicare Part D. Usually, the Rx generic version is covered. The OTC version is usually only covered (with a prescription) under certain insurances.

The out-of-pocket price (without insurance) for 30 capsules of 30 mg lansoprazole (generic Prevacid) is about $125 but you can get the generic prescription for about $15, and the price for 30 capsules of 20 mg omeprazole (generic Prilosec) is about $60. You can pay approximately $15 for generic Prilosec with SingleCare.

  Prevacid Prilosec
Typically covered by insurance? Yes. Rx generic, usually not OTC Yes. Rx generic, usually not OTC
Typically covered by Medicare Part D? Yes. Rx generic, usually not OTC Yes. Rx generic, usually not OTC
Standard dosage Example: 30 mg capsule daily Example: 20 mg capsule daily
Typical Medicare Part D copay $4-$64 $0-$20
SingleCare cost $12-$20 $9-$20

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Common side effects of Prevacid vs. Prilosec

Prevacid and Prilosec tend to be well-tolerated in patients. The most common side effects of Prevacid are diarrhea and abdominal pain, followed by constipation, nausea, and headache. The most common side effects of Prilosec are headache and abdominal pain, followed by nausea, diarrhea, vomiting, and flatulence.

Consult a healthcare professional for a complete list of side effects.

  Prevacid Prilosec
Side Effect Applicable? Frequency Applicable? Frequency
Abdominal pain Yes 2.1% Yes 5%
Constipation Yes 1% Yes 2%
Diarrhea Yes 3.8% Yes 4%
Nausea Yes 1.3% Yes 4%
Headache Yes 1% Yes 7%
Vomiting Yes <1% Yes 3%
Flatulence Yes <1% Yes 3%

Source: DailyMed (Prevacid), DailyMed (Prilosec)

Drug interactions of Prevacid vs. Prilosec

Because Prevacid and Prilosec are similar, they have many of the same drug interactions. Both drugs interact with blood thinners such as Coumadin (warfarin); certain antiretrovirals; methotrexate; St. John’s Wort; rifampin; and Lanoxin (digoxin). Some of the interactions are different for each drug; see the chart below for details. Consult your healthcare provider for personalized advice based on the medications you take.

Drug Drug Class Prevacid Prilosec
Edurant (rilpivirine)
Invirase (saquinavir)
Reyataz (atazanavir)
Viracept (nelfinavir)
Antiretroviral Yes Yes
Coumadin (warfarin) Anticoagulant Yes Yes
Methotrexate Antimetabolite Yes Yes
Lanoxin (digoxin) Cardiac glycoside Yes Yes
Celexa (citalopram) SSRI antidepressant No Yes
Pletal (cilostazol) Vasodilator No Yes
Dilantin (phenytoin) Anticonvulsant No Yes
Valium (diazepam) Benzodiazepine No Yes
Theophylline Methylxanthines Yes No
Sporanox (itraconazole)
Iron salts
CellCept (mycophenolate)
Drugs that depend on gastric pH for absorption Yes Yes
Prograf (tacrolimus) Immunosuppressant Yes Yes
St. John’s Wort rifampin CYP3A4 enzyme inducers Yes Yes
Carafate (sucralfate) Ulcer protectant Yes Yes
Plavix Anti-platelet No Yes

Warnings of Prevacid vs. Prilosec

Because they are in the same drug class, Prevacid and Prilosec have many of the same warnings:

  • A response in symptoms to the medication does not rule out malignancy. Appropriate testing should be done, including an endoscopy in the elderly.
  • Acute interstitial nephritis (a potentially serious kidney condition) could occur at any time during treatment due to a hypersensitivity reaction.
  • Because of potentially serious effects due to higher doses and long-term use, patients should be treated with the lowest dose, and for the shortest time required, in order to:
    • lower the risk of Clostridium difficile diarrhea, especially in hospitalized patients.
    • reduce the risk of PPI-associated bone fracture.
    • reduce the risk of cutaneous lupus erythematosus (CLE) and systemic lupus erythematosus (SLE).
  • Prevacid or Prilosec may cause vitamin B12 deficiency.
  • Prevacid or Prilosec may cause low magnesium (with or without symptoms). While rare, most of the cases have occurred in patients taking a PPI for over a year, serious cases have caused muscle spasms, seizures, and abnormal heart rhythm.
  • Prevacid or Prilosec may cause false-positive results in testing for neuroendocrine tumors.
  • Prevacid or Prilosec can lead to methotrexate toxicity if taken in combination with methotrexate.
  • There is an increased risk of fundic gland polyps with Prevacid or Prilosec.
  • Avoid using with St. John’s Wort or rifampin, either of which could prevent Prevacid or Prilosec from working properly.

Additional warnings of Prilosec:

  • Avoid using with Plavix (clopidogrel); Prilosec will stop clopidogrel from working properly. A different antiplatelet drug should be used instead of Plavix.

Pregnancy warnings:

Consult your healthcare provider for medical advice. If you are already taking Prevacid or Prilosec, and find out you are pregnant, consult your doctor.

Frequently asked questions about Prevacid vs. Prilosec

What is Prevacid?

Prevacid, or lansoprazole, is a proton pump inhibitor. It works by decreasing acid production and helping symptoms of acid reflux. Prevacid is available by prescription as well as OTC (over-the-counter) in both brand-name and generic.

What is Prilosec?

Prilosec, or omeprazole, is also a drug in the proton pump inhibitor class of medications. It is available in both prescription and OTC form, in both brand and generic.

Are Prevacid and Prilosec the same?

Because they are in the same drug class, they work in the same way but have some differences in indications, cost, drug interactions, side effects, and warnings.

Is Prevacid or Prilosec better? / Does lansoprazole work better than omeprazole?

Looking at the available data, both PPIs seem to be similar in terms of safety and efficacy. Prevacid may be slightly more effective in the short-term, but over time, the drugs have similar results. Your doctor can help you decide if Prevacid or Prilosec is right for you.

Can I use Prevacid or Prilosec while pregnant?

It is difficult to say. There is some conflicting information and not enough information. Consult your OB/GYN for advice. If you are already taking Prevacid or Prilosec, and find out you are pregnant, consult your OB/GYN.

Can I use Prevacid or Prilosec with alcohol?

Although the manufacturers of each drug do not specifically warn against alcohol in combination with the medication, drinking alcohol can increase acidity and worsen the symptoms of reflux.

What are the dangers of taking Prilosec?

Both Prilosec and Prevacid come with warnings, which are detailed above. Your doctor will monitor your response, as well as any adverse reactions, to Prevacid or Prilosec.

What foods neutralize stomach acid?

Some great foods to eat to help reduce stomach acid are bananas; melon (cantaloupe, honeydew); whole grains such as oatmeal; yogurt; lean proteins; and green vegetables (asparagus, kale, spinach, brussels sprouts).

Avoid foods that are fried, high in fat, or spicy. Other irritating foods and drinks to avoid include pineapples, citrus fruit (and their juices), tomatoes (and sauces, salsa, juice, etc), garlic, onions, alcohol, carbonated beverages, coffee, tea, chocolate, and mint. Keeping a food diary may help you to narrow down which foods and beverages help or hurt your symptoms.

What is the most effective proton pump inhibitor?

In addition to Prevacid and Prilosec, there are other FDA approved proton pump inhibitors that are available, including Protonix (pantoprazole), Nexium (esomeprazole), Aciphex (rabeprazole), and Dexilant (dexlansoprazole). Each drug works in a similar way to block acid production and relieve symptoms, but since everyone is different, you may respond better to one drug over another. Consult your healthcare professional for medical advice. Other popular heartburn drugs such as Zantac (ranitidine) and Pepcid (famotidine) are in the drug class known as H2 blockers and are not PPIs.