Lansoprazole

pronounced as (lan soe' pra zole)

Brand Name(s): Prevacid®, Prevacid®SoluTab®, Prevacid® 24HR, Prevacid®NapraPAC®(as a combination product containing Lansoprazole, Naproxen) ¶, also available generically
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Why is this medicine prescribed?

Prescription lansoprazole is used to

  • treat gastroesophageal reflux disease (GERD; a condition where stomach acid flows back into the esophagus (tube between the stomach and throat))
  • treat and prevent ulcers (sores in the lining of the stomach or intestine)
  • treat conditions where the stomach produces too much acid, such as Zollinger-Ellison syndrome
  • treat and prevent the return of stomach ulcers caused by a certain type of bacteria (H. pylori) in adults
  • treat heartburn

Lansoprazole is in a class of medications called proton pump inhibitors. It works by decreasing the amount of acid made in the stomach.

Are there other uses for this medicine?

This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.

How should this medicine be used?

Lansoprazole comes as a delayed-release (releases the medication in the intestine to prevent break-down of the medication by stomach acids) capsule to take by mouth.  Take lansoprazole once or twice a day. Take lansoprazole at around the same time(s) every day.

Take lansoprazole exactly as directed. Do not take more or less of it or take it more often or for a longer time than prescribed by your doctor or stated on the package. Tell your doctor if you have taken nonprescription lansoprazole for a longer period of time than stated on the package.

Swallow the capsules whole; do not split, chew, or crush them. If you have difficulty swallowing capsules, you may open the capsule, sprinkle the granules on 1 tablespoon of applesauce, Ensure ® pudding, cottage cheese, yogurt, or strained pears and swallow the mixture immediately without chewing. You can also open a capsule and pour the contents into 2 ounces (60 milliliters) of orange juice, apple juice or tomato juice, mix briefly, and swallow immediately. After you swallow the mixture, rinse the glass with some additional juice and drink immediately. Then rinse the glass with juice at least two more times and drink the juice to be sure that you wash all the medication out of the glass.

The capsule contents can be given through a feeding tube. If you have a feeding tube, ask your doctor how you should take the medication. Follow these directions carefully.

Do not take nonprescription lansoprazole for immediate relief of heartburn symptoms. It may take 1 to 4 days for you to feel the full benefit of the medication. Call your doctor if your symptoms get worse or do not improve after 14 days or if your symptoms return sooner than 4 months after you finish your treatment. Do not take nonprescription lansoprazole for longer than 14 days or treat yourself with lansoprazole more often than once every 4 months without talking to your doctor.

Continue to take lansoprazole even if you feel well. Do not stop taking prescription lansoprazole without talking to your doctor. If your condition does not improve or gets worse, call your doctor.

What special precautions should I follow?

Before taking lansoprazole,

  • tell your doctor or pharmacist if you are allergic to this medication, any part of this medication, or any other medications, foods or substances. Tell your doctor or pharmacist about the allergy and what symptoms you had.
  • some medications should not be taken with lansoprazole. Other medications may cause dosing changes or extra monitoring when taken with lansoprazole. Make sure you have discussed any medications you are currently taking or plan to take before starting lansoprazole with your doctor and pharmacist. Before starting, stopping, or changing any medications while taking lansoprazole, please get the advice of your doctor or pharmacist.
  • you should know that the following nonprescription or herbal products may interact with lansoprazole: iron supplements, St. John's wort. Be sure to let your doctor and pharmacist know that you are taking these medications before you start taking lansoprazole. Do not start any of these medications while taking lansoprazole without discussing with your healthcare provider.
  • you should know that if you are taking sucralfate (Carafate®), take it at least 30 minutes after lansoprazole.
  • tell your doctor if you have or have ever had a low level of magnesium, calcium, potassium, or sodium in your blood; hypoparathyroidism (condition in which the body does not produce enough parathyroid hormone [PTH; a natural substance needed to control the amount of calcium in the blood]); low levels of vitamin B12 in your body; osteoporosis (a condition in which the bones become thin and weak and break easily); an autoimmune disease (condition in which the body attacks its own organs, causing swelling and loss of function) such as systemic lupus erythematosus; or liver disease.
  • if you plan to take nonprescription lansoprazole, first tell your doctor if your heartburn has lasted 3 months or longer or if you have experienced any of the following symptoms: lightheadedness, sweating, or dizziness along with your heartburn; chest pain or shoulder pain; shortness of breath or wheezing; pain that spreads to your arms, neck, or shoulders; unexplained weight loss; nausea; vomiting, especially if the vomit is bloody; stomach pain; difficulty swallowing food or pain when you swallow food; or black or bloody stools. You may have a more serious condition that cannot be treated with a nonprescription medication.
  • tell your doctor if you are pregnant, plan to become pregnant, or are breastfeeding. If you become pregnant while taking lansoprazole, call your doctor.
  • if you are 65 years of age or older, do not take this medication for a longer period of time than recommended on the product label or by your doctor.
  • if you have phenylketonuria (PKU, a condition in which a special diet must be followed to prevent damage to your brain), you should know that the orally disintegrating tablets may contain aspartame, which forms phenylalanine.

What special dietary instructions should I follow?

Unless your doctor tells you otherwise, continue your normal diet.

What should I do if I forget to take a dose?

Take the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your dosing schedule. Do not take a double dose to make up for a missed one.

What should I do in case of overdose?

In case of overdose, call the poison control helpline at 1-800-222-1222. Information is also available online at https://www.poisonhelp.org/help . If the victim has collapsed, had a seizure, has trouble breathing, or can't be awakened, immediately call emergency services at 911.

What side effects can this medicine cause?

Lansoprazole may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

  • nausea, diarrhea; constipation
  • headache
  • dizziness
  • in men, difficulty achieving or maintaining an erection

Some side effects can be serious. If you experience any of the following symptoms, call your doctor immediately:

  • rash; hives; itching; swelling of the eyes, face, lips, mouth, throat, or tongue; difficulty breathing or swallowing; hoarseness
  • blistering, peeling, or bleeding skin; sores on the lips, nose, mouth, or genitals; swollen glands; shortness of breath; fever; flu-like symptoms
  • increased or decreased urination, blood in urine, fatigue, nausea, loss of appetite, fever, rash, or joint pain
  • irregular, fast, or pounding heartbeat; muscle spasms; uncontrollable shaking of a part of the body; excessive tiredness; lightheadedness; dizziness; or seizures
  • severe diarrhea with watery stools, stomach pain, or fever that does not go away
  • new or worsening joint pain; rash on cheeks or arms that is sensitive to sunlight

Lansoprazole may cause other side effects. Call your doctor if you have any unusual problems while you are taking the medication.

People who take proton pump inhibitors such as lansoprazole may be more likely to fracture their wrists, hips, or spine than people who do not take one of these medications. People who take proton pump inhibitors may also develop fundic gland polyps (a type of growth on the stomach lining). These risks are highest in people who take high doses of one of these medications or take them for 1 year or longer. Talk to your doctor about the risk of taking lansoprazole.

If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online ( https://www.fda.gov/Safety/MedWatch ) or by phone ( 1-800-332-1088).

What should I know about storage and disposal of this medication?

Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom).

Keep all medication out of sight and reach of children as many containers are not child-resistant. Always lock safety caps. Place the medication in a safe location – one that is up and away and out of their sight and reach. https://www.upandaway.org Dispose of unneeded medications in a way so that pets, children, and other people cannot take them. Do not flush this medication down the toilet. Use a medicine take-back program. Talk to your pharmacist about take-back programs in your community. Visit the FDA's Safe Disposal of Medicines website https://goo.gl/c4Rm4p for more information.

What other information should I know?

Keep all appointments with your doctor and the laboratory. Your doctor may order certain laboratory tests before and during your treatment.

Before having any laboratory test, tell your doctor and the laboratory personnel that you are taking lansoprazole.

Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.

Keep a written list of all of the prescription and nonprescription (over-the-counter) medicines, vitamins, minerals, and dietary supplements you are taking. Bring this list with you each time you visit a doctor or if you are admitted to the hospital. You should carry the list with you in case of emergencies.

This branded product is no longer on the market. Generic alternatives may be available.

This report on medications is for your information only, and is not considered individual patient advice. Because of the changing nature of drug information, please consult your physician or pharmacist about specific clinical use.

The American Society of Health-System Pharmacists, Inc. represents that the information provided hereunder was formulated with a reasonable standard of care, and in conformity with professional standards in the field. The American Society of Health-System Pharmacists, Inc. makes no representations or warranties, express or implied, including, but not limited to, any implied warranty of merchantability and/or fitness for a particular purpose, with respect to such information and specifically disclaims all such warranties. Users are advised that decisions regarding drug therapy are complex medical decisions requiring the independent, informed decision of an appropriate health care professional, and the information is provided for informational purposes only. The entire monograph for a drug should be reviewed for a thorough understanding of the drug's actions, uses and side effects. The American Society of Health-System Pharmacists, Inc. does not endorse or recommend the use of any drug. The information is not a substitute for medical care.

AHFS ® Patient Medication Information™. © Copyright, 2026. The American Society of Health-System Pharmacists ® , 4500 East-West Highway, Suite 900, Bethesda, Maryland. All Rights Reserved. Duplication for commercial use must be authorized by ASHP.

Selected Revisions: October 15, 2026.