Generic name: Omeprazole Delayed-Release Capsules [ oh-MEP-ra-zole ]
Brand names: Losec, Prilosec
Drug class: Proton pump inhibitors

Medically reviewed by Drugs.com. Last updated on Apr 5, 2024.

Uses of Losec:

• It is used to treat or prevent GI (gastrointestinal) ulcers caused by infection.
• It is used to treat gastroesophageal reflux disease (GERD; acid reflux).
• It is used to treat heartburn.
• It is used to treat syndromes caused by lots of stomach acid.
• It is used to treat or prevent ulcers of the swallowing tube (esophagus).
• It may be given to you for other reasons. Talk with the doctor.

What do I need to tell my doctor BEFORE I take Losec?

• If you have an allergy to omeprazole or any other part of Losec (omeprazole delayed-release capsules).
• If you are allergic to Losec (omeprazole delayed-release capsules); any part of Losec (omeprazole delayed-release capsules); or any other drugs, foods, or substances. Tell your doctor about the allergy and what signs you had.
• If you have any of these health problems: Black or bloody stools; heartburn with light-headedness, sweating, or dizziness; chest pain; shoulder pain with shortness of breath; pain that spreads to the arms, neck, or shoulders; light-headedness; sweating a lot; throwing up blood; or trouble or pain swallowing food.
• If you are taking any of these drugs: Atazanavir, clopidogrel, nelfinavir, rifampin, rilpivirine, or St. John's wort.

This is not a list of all drugs or health problems that interact with Losec (omeprazole delayed-release capsules).

Tell your doctor and pharmacist about all of your drugs (prescription or OTC, natural products, vitamins) and health problems. You must check to make sure that it is safe for you to take Losec (omeprazole delayed-release capsules) with all of your drugs and health problems. Do not start, stop, or change the dose of any drug without checking with your doctor.

What are some things I need to know or do while I take Losec?

• Tell all of your health care providers that you take Losec (omeprazole delayed-release capsules). This includes your doctors, nurses, pharmacists, and dentists.
• This medicine may affect certain lab tests. Tell all of your health care providers and lab workers that you take Losec (omeprazole delayed-release capsules).
• This medicine may raise the chance of hip, spine, and wrist fractures in people with weak bones (osteoporosis). The chance may be higher if you take Losec (omeprazole delayed-release capsules) in high doses or for longer than a year, or if you are older than 50 years old.
• Use care if you have risks for soft, brittle bones (osteoporosis). Some of these risks include drinking alcohol, smoking, taking steroids, taking drugs to treat seizures, or having family members with osteoporosis. Talk with your doctor about your risks of osteoporosis.
• Rarely, low magnesium levels have happened in people taking drugs like this one for at least 3 months. Most of the time, this happened after 1 year of treatment. You will need to have blood work if you take Losec (omeprazole delayed-release capsules) for a long time or with certain other drugs.
• Rarely, long-term treatment (for instance longer than 3 years) with drugs like this one has caused low vitamin B-12 levels. Call your doctor right away if you have signs of low vitamin B-12 levels like shortness of breath, dizziness, abnormal heartbeat, muscle weakness, pale skin, tiredness, mood changes, or numbness or tingling in the arms or legs.
• Do not take Losec (omeprazole delayed-release capsules) for longer than you were told by your doctor.
• Lupus has happened with Losec (omeprazole delayed-release capsules), as well as lupus that has gotten worse in people who already have it. Tell your doctor if you have lupus. Call your doctor right away if you have signs of lupus like a rash on the cheeks or other body parts, sunburn easy, muscle or joint pain, chest pain or shortness of breath, or swelling in the arms or legs.
• Very bad pancreas, liver, and white blood cell problems have happened in people who were taking Losec (omeprazole delayed-release capsules). Rarely, these have been fatal. Talk with the doctor if you have questions.
• If you are of Asian descent, use Losec (omeprazole delayed-release capsules) with care. You could have more side effects.
• Tell your doctor if you are pregnant, plan on getting pregnant, or are breast-feeding. You will need to talk about the benefits and risks to you and the baby.

How is this medicine (Losec) best taken?

Use Losec (omeprazole delayed-release capsules) as ordered by your doctor. Read all information given to you. Follow all instructions closely.

• Take Losec (omeprazole delayed-release capsules) before meals.
• Keep taking Losec (omeprazole delayed-release capsules) as you have been told by your doctor or other health care provider, even if you feel well.
• Swallow whole. Do not chew or crush.
• You may sprinkle contents of capsule on applesauce. Do not chew. Swallow right away and follow with cool water.
• After mixing, take your dose right away. Do not store for future use.

What do I do if I miss a dose?

• Take a missed dose as soon as you think about it.
• If it is close to the time for your next dose, skip the missed dose and go back to your normal time.
• Do not take 2 doses at the same time or extra doses.

Related/similar drugs

omeprazole, amoxicillin, famotidine, pantoprazole, metronidazole, esomeprazole, sucralfate, Nexium, Protonix, lansoprazole

What are some side effects that I need to call my doctor about right away?

WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:

• Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing, swallowing, or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.
• Signs of low magnesium levels like mood changes, muscle pain or weakness, muscle cramps or spasms, seizures, shakiness, not hungry, very bad upset stomach or throwing up, or a heartbeat that does not feel normal.
• Signs of kidney problems like unable to pass urine, change in how much urine is passed, blood in the urine, or a big weight gain.
• Signs of infection like fever, chills, very bad sore throat, ear or sinus pain, cough, more sputum or change in color of sputum, pain with passing urine, mouth sores, or wound that will not heal.
• Signs of liver problems like dark urine, feeling tired, not hungry, upset stomach or stomach pain, light-colored stools, throwing up, or yellow skin or eyes.
• Signs of a pancreas problem (pancreatitis) like very bad stomach pain, very bad back pain, or very bad upset stomach or throwing up.
• Very bad dizziness or passing out.
• Bone pain.
• A big weight loss.
• Feeling very tired or weak.
• This medicine may raise the chance of a severe form of diarrhea called C diff-associated diarrhea (CDAD). Call your doctor right away if you have stomach pain or cramps, very loose or watery stools, or bloody stools. Do not try to treat diarrhea without first checking with your doctor.
• A very bad skin reaction (Stevens-Johnson syndrome/toxic epidermal necrolysis) may happen. It can cause very bad health problems that may not go away, and sometimes death. Get medical help right away if you have signs like red, swollen, blistered, or peeling skin (with or without fever); red or irritated eyes; or sores in your mouth, throat, nose, or eyes.

What are some other side effects of Losec?

All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your doctor or get medical help if any of these side effects or any other side effects bother you or do not go away:

• Headache.
• Upset stomach or throwing up.
• Stomach pain or diarrhea.
• Gas.

These are not all of the side effects that may occur. If you have questions about side effects, call your doctor. Call your doctor for medical advice about side effects.

You may report side effects to the FDA at 1-800-332-1088. You may also report side effects at https://www.fda.gov/medwatch.

If OVERDOSE is suspected:

If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.

How do I store and/or throw out Losec?

• Store at room temperature in a dry place. Do not store in a bathroom.
• Protect from light.
• Keep all drugs in a safe place. Keep all drugs out of the reach of children and pets.
• Throw away unused or expired drugs. Do not flush down a toilet or pour down a drain unless you are told to do so. Check with your pharmacist if you have questions about the best way to throw out drugs. There may be drug take-back programs in your area.

Consumer Information Use and Disclaimer

• If your symptoms or health problems do not get better or if they become worse, call your doctor.
• Do not share your drugs with others and do not take anyone else's drugs.
• This medicine comes with an extra patient fact sheet called a Medication Guide. Read it with care. Read it again each time Losec (omeprazole delayed-release capsules) is refilled. If you have any questions about Losec (omeprazole delayed-release capsules), please talk with the doctor, pharmacist, or other health care provider.
• If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.

Frequently asked questions

• Pantoprazole vs. omeprazole: What's the difference between them?
• What foods should I avoid when taking omeprazole?
• Is famotidine safer than omeprazole for heartburn?
• Can you take an antacid with omeprazole?
• Can I take omeprazole in the morning and famotidine at night?
• Is omeprazole (Prilosec) bad for your kidneys?
• Does omeprazole cause cancer?
• How soon after taking levothyroxine can I take omeprazole?
• When's the best time to take omeprazole: before or after a meal?

View more FAQ

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Medical Disclaimer