Omeprazole (Prilosec®)

Printable PDF version

About This Drug

Omeprazole is used to treat and prevent stomach ulcers. It is also used in combination to treat helicobacter pylori. It is given orally (by mouth) but can also be given in the vein (IV).

Possible Side Effects

  • Headache
  • Pain in your abdomen
  • Nausea and vomiting (throwing up)
  • Loose bowel movements (vomiting)
  • Gas

Note: Each of the side effects above was reported in 2% or greater of patients treated with omeprazole. Not all possible side effects are included above.

Warnings and Precautions

  • Changes in your kidney function such as inflammation
  • Severe diarrhea, that can be caused by an infection called clostridium difficile
  • Inflammation of the stomach with long-term use
  • Increased risk of bone fractures
  • Risk of developing systemic lupus erythematosus, which is an autoimmune disorder that can attack cells and organs in your body. If you already have systemic lupus, omeprazole may make it worse.
  • Decreased or increased absorption of drugs or vitamins – that may require additional monitoring
  • Changes in your electrolytes especially low magnesium

Note: Some of the side effects above are very rare. If you have concerns and/or questions, please discuss them with your medical team.

How to Take Your Medication

  • Take this medicine before meals.
  • Delayed-Release Capsules: Swallow capsules whole. Do not chew or crush. If you have trouble swallowing, the capsules can be opened and mixed with applesauce. Please refer to the instructions of the package insert or speak to your nurse and/or pharmacist for proper preparation and administration.
  • Delayed-Release Oral Suspension: The suspension can be mixed with water and taken by mouth. Please refer to the instructions of the package insert or speak to your nurse and/or pharmacist for proper preparation and administration.
  • Missed dose: If you miss a dose, take it as soon as you think about it unless it is close to your next regular dose. Do not take 2 doses at the same time and do not double up on the next dose.
  • Storage: Store this medicine in the original container at room temperature. Discuss with your nurse or your doctor how to dispose of unused medicine.

Treating Side Effects

  • Keeping your pain under control is important to your well-being. Please tell your doctor or nurse if you are experiencing pain.
  • To help with gas, avoid gas-producing foods, such as Brussels sprouts, cabbage, cauliflower, carrots, prunes and apricots.
  • Drink plenty of fluids (a minimum of eight glasses per day is recommended).
  • If you throw up or have loose bowel movements, you should drink more fluids so that you do not become dehydrated (lack water in the body from losing too much fluid).
  • To help with nausea and vomiting, eat small, frequent meals instead of three large meals a day. Choose foods and drinks that are at room temperature. Ask your nurse or doctor about other helpful tips and medicine that is available to help or stop lessen these symptoms.
  • If you have diarrhea, eat low-fiber foods that are high in protein and calories and avoid foods that can irritate your digestive tracts or lead to cramping.
  • Ask your nurse or doctor about medicine that can lessen or stop your diarrhea.

Food and Drug Interactions

  • There are no known interactions of omeprazole with food; however, this medication should be taken on an empty stomach, before meals.
  • Check with your doctor or pharmacist about all other prescription medicines and over-the-counter medicines and dietary supplements (vitamins, minerals, herbs and others) you are taking before starting this medicine as there are known drug interactions with omeprazole. Also, check with your doctor or pharmacist before starting any new prescription or over-the-counter medicines, or dietary supplements to make sure that there are no interactions.
  • Avoid the use of St. John’s Wort while taking omeprazole as this may lower the levels of the drug in your body, which can make it less effective

When to Call the Doctor

Call your doctor or nurse if you have any of these symptoms and/or any new or unusual symptoms:

  • Headache that does not go away
  • Nausea that stops you from eating or drinkingand/or is not relieved by prescribed medicines
  • Throwing up more than 3 times a day
  • Loose bowel movements (diarrhea) 4 times a day or loose bowel movements with lack of strength or a feeling of being dizzy
  • Pain in your abdomen that does not go away
  • Decreased urine, or very dark urine
  • Blood in your urine
  • Muscle aching or cramping
  • Muscle weakness
  • Spasms/shaking in your hands and feet
  • If you think you may be pregnant

Reproduction Warnings

  • Pregnancy warning: It is not known if this drug may harm an unborn child. For this reason, be sure to talk with your doctor if you are pregnant or planning to become pregnant while receiving this drug. Let your doctor know right away if you think you may be pregnant
  • Breastfeeding warning: This drug passes into breast milk. For this reason, women should talk to their doctor about the risks and benefits of breastfeeding during treatment with this drug because this drug can enter the breast milk and may cause harm to a breastfeeding baby.
  • Fertility warning: Human fertility studies have not been done with this drug. Talk with your doctor or nurse if you plan to have children.

New April 2018

This patient information was developed by Via Oncology, LLC © 2018. This information is not intended to be used as a substitute for professional medical advice, diagnosis, or treatment. You should not rely entirely on this information for your health care needs. Ask your own doctor or health care provider any specific medical questions that you have.

CLIENT acknowledges that the Via Pathways and Via Portal are information management tools only, and that Via Oncology, LLC has not represented the Via Pathways or Via Portal as having the ability to diagnose disease, prescribe treatment, or perform any other tasks that constitute the practice of medicine. The clinical information contained in the Via Pathways and Via Portal are intended as a supplement to, and not a substitute for, the knowledge, expertise, skill, and judgment of physicians, pharmacists and other healthcare professionals involved with patient care at CLIENT facilities.