Report on Prilosec Side Effects and Usage by AskDocWeb

About Prilosec

This article covers the uses of Prilosec, side effects, dosage, precautions, drug interactions, usage, adverse reactions, long-term use, overdose, pregnancy, and elimination.

What is Prilosec?

Prilosec is a brand name of the drug omeprazole, pronounced (oh me’ pray zol). Omeprazole is available as tablets and capsules in strengths of 10 mg, 20 mg, and 40 mg by prescription and over-the-counter (OTC).

What is Prilosec used for?

Prilosec is used to treat gastroesophageal reflux disease (GERD), a condition in which the flow of stomach acid reverses causing heartburn and possible injury of the esophagus (the tube that goes from your throat to the stomach).

Other disorders/conditions treated with Prilosec include:

  • Dyspepsia (a disorder of digestive function characterized by discomfort or heartburn or nausea)
  • Laryngopharyngeal reflux (LPR)
  • Infection by H. pylori
  • Peptic Ulcer Disease (PUD)
  • Zollinger-Ellison syndrome

Before using Prilosec

Tell your doctor if you are pregnant, plan to become pregnant, or if you are breast-feeding. If you become pregnant while taking omeprazole, call your doctor.

Tell your doctor if you are of Asian descent.

Tell your doctor if you have or have a history of low level of magnesium in your blood or liver disease.

Tell your doctor if you are allergic to any medications. Ask your pharmacist or check the package label for a list of the ingredients.

Tell your doctor if your heartburn has lasted for 3 months or longer or if you have any of the following symptoms:

  • lightheadedness
  • sweating
  • dizziness along with your heartburn
  • chest pain
  • 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
  • black or bloody stools

Any of the above may indicate a more serious condition that cannot be treated with this medication.

How does Prilosec work?

Prilosec works by decreasing the amount of acid made in the stomach. Drugs that have this effect are called proton-pump inhibitors.

How long does it take to work?

This drug does not provide immediate relief of heartburn symptoms. It takes a few days to start feeling the effects of Prilosec, typically from 2 to 4 days. Call your doctor if your symptoms get worse or don’t improve after 14 days or if your symptoms return within 4 months after finishing treatment. Do not take Prilosec OTC for longer than 14 days or treat yourself with this drug more often than once every 4 months without talking to your doctor.

Prilosec Side Effects

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

  • constipation
  • diarrhea
  • fever
  • gas
  • headache
  • nausea
  • vomiting
  • stomach or abdominal pain (2%)

Adverse reactions are possible when taking any drug. If you experience any of the following serious symptoms, call your doctor immediately:

  • difficulty breathing or swallowing
  • dizziness
  • excessive tiredness
  • hives
  • hoarseness
  • irregular, fast, or pounding heartbeat
  • itching
  • lightheadedness
  • muscle spasms
  • rash
  • seizures
  • swelling of the face, throat, tongue, lips, eyes, hands, feet, ankles, or lower legs
  • uncontrollable shaking of a part of the body

Drug Interactions

Using Prilosec with certain other drugs may change the effectiveness of those drugs in an undesirable way. Drug/drug interactions for Prilosec include:

  • Atazanavir
  • Clopidogrel (Plavix)
  • Diazepam
  • Erythromycin
  • Escitalopram
  • Ketoconazole
  • Warfarin

If you are using one of the above drugs discuss this possibility with your doctor.

Symptoms of Overdose

An overdose may include one or more of the following:

  • confusion
  • drowsiness
  • blurred vision
  • fast or pounding heartbeat
  • nausea
  • vomiting
  • sweating
  • flushing (feeling of warmth)
  • headache
  • dry mouth

If you suspect an overdose call your local poison control center at 1-800-222-1222. If the victim has collapsed or is not breathing, call 911 for emergency services.


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

What if I forget a dose?

Take the missed dose as soon as you remember it. You can skip the missed dose if it is almost time for your next dose and then continue your regular dosing schedule. Do not take two or double up on the dosage to make up for a missed one.

General Notes

Follow the directions on the label carefully, and ask your doctor or pharmacist to explain anything you do not understand. Take omeprazole exactly as directed. Do not take more or less of it or take it more often or for a longer period of time than prescribed by your doctor or stated on the package. Tell your doctor if you have taken Prilosec for longer than 14 days.

Prescription Prilosec comes as a delayed-release capsule, and packets of delayed-release granules for suspension (to be mixed with liquid) to take by mouth. Nonprescription Prilosec OTC comes as a delayed-release capsule or tablet to take by mouth. The delayed-release capsules and the granules are usually taken at least 1 hour before a meal.

The half-life of Prilosec is 0.5 to 1.0 hour and is totally cleared from the body within 10 hours. The effect of this drug may persist for slightly over 24 hours. Prilosec is metabolized mainly in the liver. 80% is excreted in the urine and 20% in fecal matter.

Pregnancy Category: C. It is not known whether or not Prilosec will harm an unborn baby. Tell your doctor if you are pregnant or plan on becoming pregnant before taking this drug.

The effectiveness of Prilosec significantly reduced by the presence of food and, therefore, patients should be advised to take this medication with a glass of water on an empty stomach (i.e., no eating for at least 60 minutes before taking it). Most sources recommend waiting at least 30 minutes before eating to allowed the drug to take effect. (at least 60 minutes for immediate-release combination formula such as Zegerid), although some sources say that this is not necessary with the delayed-release forms.

Kidney inflammation: Since its introduction, Prilosec (and other proton pump inhibitors) have been associated with several cases of acute inflammation of the kidneys (tubulointerstitial nephritis), which often occurs as an adverse drug reaction.

Long-term Use: Some people who take Prilosec for a long time may develop weakening of the stomach lining.

Bone problems: People who take proton pump inhibitors such as Prilosec may be more likely to fracture bones in their wrists, hips, or spine than people who do not take one of these medications. The risk is highest in people who take high doses or use them long-term, one year or longer.

A study of nearly 14,000 hip fracture cases in Britain reports elderly people who take drugs like Prilosec, Prevacid, or Nexium may make it difficult for the body to absorb calcium. According to Dr. Olufemi Abiodun at Marshfield Clinic, “The longer you are taking this medication they found out that they risk of fractures actually goes up almost exponentially.” The researchers report a 44 percent increased risk of breaking a hip during a fall.

Risk of pneumonia: Patients who are administered this drug in intensive care as a protective measure against ulcers may have up to a 30% increase in the occurrence of pneumonia. The risk of pneumonia may also be higher in people taking other PPIs.

Prilosec is also sold in combination with other products:

  • Zegerid contains Omeprazole and Sodium Bicarbonate.
  • Zegerid with Magnesium Hydroxide contains Magnesium Hydroxide, Omeprazole, and Sodium

Keep all of your doctor and laboratory appointments while taking this medicine. Your doctor may order laboratory tests before and during your treatment.

If you are taking the delayed-release tablets, swallow them whole with a full glass of water. Do not bit, chew, split, or crush them.

This page does not list everything you need to know about Prilosec. Ask your pharmacist or doctor for a copy of the manufacturer’s information for the patient.

We recommend you keep health note list on you at all times. This is a list of your current health conditions, all prescription and nonprescription (over-the-counter) medicines you are taking, as well as any vitamins, minerals, or other supplements. You should take this list with you each time you visit a doctor or if you are admitted to a hospital. It is also helpful to carry this list on you in case of an emergency.

Prilosec is just one of the many brand names for omeprazole, which is marketed around the world as Antra, Aspra, Gastroloc, Losec, Lozeprel, Mopral, Omepral, OMEZ (Farhaad), Opal, Ozid Capsule, Prilosec OTC, Segazole, Ulcozol, Xelopes, Zegerid OTC, and Zegerid.

Ordering Prilosec

Prilosec is available from your local pharmacy or drugstore.

Prilosec Feedback

If your have questions, concerns or comments about Prilosec help others by adding your feedback.

Subj: Breathing problems after starting Prilosec
Date: 7/30/2008
Seven days after starting Prilosec I began having breathing problems that caused me to think I had COPD or emphysema. The doctor said I had acid reflux and that was causing the breathing problems. Began having to yawn several times to get my breath. Ultimately ended up in the emergency room after 13 days on Prilosec because I couldn’t breathe. They said it was an anxiety attack. I had not experienced that kind of anxiety before and told them that this started with the medication. The doctor then put me on Protonix, said it would work better.

I continued to get worse, so sick I could not eat. I stopped taking it and was just using Pepto and Mylanta and Tums, but my breathing never got better. Like a catch so that I could not get a deep breath. Another doctor said the only medication that would help was Nexium, and though I tried to convince him that I could not take proton pump inhibitors, he insisted this one was different. Withing 5 days I was so sick again, the breathing disorder worse, skin crawling, and room spinning. I stopped it and began experiencing what I believe was rebound acid that burned all the way up into my ears.

I lost 30 lbs. in 2 months because I was unable to eat and all this started with these medications. The week before I started Prilosec, I ate at the Cheesecake Factory, Olive Garden, Crabshack, and Tai House with no uspet stomach. Am not sure I even had reflux, but I have never been so sick in my life as I have been since starting these medications.


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Most recent post: September 19, 2016

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