Fact Checked

What Is Omeprazole?

Although many people experience heartburn or indigestion occasionally, an estimated 15 to 30 percent of Americans suffer from gastroesophageal reflux disease or GERD. GERD is characterized by the experience of heartburn or indigestion at least twice per week.  The International Foundation for Gastrointestinal Disorders reports that rates of GERD are skyrocketing in the United States due to a number of factors, including the rising obesity rates, as people who are overweight or obese are more likely to suffer from GERD. There are several different ways to treat GERD, depending on its severity, including lifestyle changes like dietary changes or weight loss, lifestyle changes combined with over the counter antacid medications like Pepcid and Tagamet, or treatment with prescription medications in combination with lifestyle changes. People with more severe or more persistent GERD may need to make lifestyle changes and take a different kind of medication or prescription drugs to treat their symptoms. There are numerous drugs on the market to treat GERD, including omeprazole, but what is omeprazole and how does it work?

What Is Omeprazole?

Omeprazole is a generic drug that is also sold under the brand name Prilosec. Omeprazole belongs to a class of medications called proton pump inhibitors (PPIs) and contains two isomers (chemical compounds that have the same formula but differ in the arrangement of their atoms) of omeprazole. Proton pump inhibitors are the most widely prescribed class of medications in the world. Omeprazole and Prilosec were originally sold by prescription only, but the U.S. Food and Drug Administration (FDA) approved Prilosec OTC (over the counter) as the first over the counter treatment for GERD in June 2003. Today, omeprazole is available over the counter at certain strengths and is also available by prescription at higher strengths. Omeprazole was the seventh most commonly prescribed medication in 2017 when nearly 59 million prescriptions were written for the drug in the United States. 

What Conditions Is Omeprazole Used to Treat?

Omeprazole is used to treat a number of digestive conditions, including GERD, Zollinger-Ellison Syndrome, gastric ulcers, duodenal ulcers, and erosive esophagitis. 

Gastroesophageal Reflux Disease 

Gastroesophageal reflux disease, also known as GERD or heartburn, is a condition that occurs when erosive gastric acid and digestive enzymes flow backward from the stomach into the esophagus. Although most people experience heartburn or acid reflux every once in a while, people with gastroesophageal reflux disease experience these symptoms at least twice per week over an extended period of time. While the occasional heartburn or indigestion can be due to eating too much spicy or acidic food, GERD is usually the result of dysfunction in the esophageal sphincter. This muscular ring is responsible for sealing off the esophagus from the stomach in order to prevent food and acid from coming back up into the esophagus, but people with GERD may have esophageal sphincters that do not function properly or seal tightly enough. When the esophageal sphincter does not seal properly, it allows food and digestive juices to enter the esophagus because it remains relaxed between swallows. The stomach acid that the stomach produces is highly acidic, and although the stomach has a special lining that usually protects it from damage, the esophagus does not. When exposed to stomach acid repeatedly over an extended period of time, the esophagus can experience inflammation, narrowing, development of open sores, or a condition called Barrett’s esophagus, which is associated with an increased risk of esophageal cancer. People with GERD often experience some or all of the following symptoms:

  • Nausea
  • A repeated sour or bitter taste in the mouth
  • Sharp or burning pain behind the breast bone
  • Sore throat
  • Coughing, wheezing or needing to clear your throat
  • Tightness in the chest or upper abdomen
  • Regurgitation
  • Difficulty swallowing
  • Hoarseness

Zollinger-Ellison Syndrome

Zollinger-Ellison syndrome is a condition that results in tumors forming in the pancreas or upper small intestines. These tumors secrete large amounts of a hormone called gastrin, which causes the stomach to overproduce acid. The additional acid can cause peptic ulcers, diarrhea, and other symptoms. The majority of people with Zollinger-Ellison syndrome are diagnosed between the ages of 20 and 50, but the condition may be present at any time in life. Symptoms associated with Zollinger-Ellison syndrome include:

  • Burning, aching, or discomfort in the upper abdomen
  • Nausea and vomiting
  • Decreased appetite
  • Diarrhea
  • Acid reflux and heartburn
  • Bleeding in the digestive tract
  • Abdominal pain

How Does Omeprazole Work?

Proton pump inhibitors like omeprazole work by blocking the action of the H+/K+ ATPase enzyme, which is found in parietal cells of the stomach. These enzymes are known as proton pumps and are responsible for the final production of hydrochloric acid, which is the primary component of stomach acid. PPIs work by decreasing the amount of acid made by proton pumps, bringing acidity levels down, and preventing the creation of excess acid. Proton pump inhibitors were first introduced in 1981 and are considered the most effective class of medications for reducing stomach acid.

What Dosage of Omeprazole Should I Take?

The dose of omeprazole taken by most adults will be between 20 to 40 mg taken once or twice daily for control of symptoms associated with GERD and other digestive conditions. Omeprazole is available over the counter in the form of 20 mg strength delayed-release capsules and is available by prescription in the form of delayed-release capsules and suspension at higher strengths. Omeprazole is typically taken for anywhere from ten days to eight weeks, but patients with chronic GERD or other digestive conditions often take this medication for extended periods of time at the direction of their healthcare provider. The medication should be taken prior to eating a meal, as it works best on an empty stomach. Omeprazole capsules should be swallowed whole and should not be crushed, divided, or chewed. Omeprazole will not take effect immediately, so you’ll need to give it about two and a half hours to kick in. Patients needing immediate relief from their symptoms can take the medication with a fast-acting acid reducer, such as Tums or Maalox. If taking the oral suspension form of omeprazole, the medication must be prepared, mixed into apple juice or apple sauce, and taken 30 minutes before a meal.

How Much Does Omeprazole Cost?

Omeprazole is considered a highly affordable medication for most people. Patients benefit from the sheer number of competitors and generic offerings, as well as the over the counter availability of many medications. The cost of omeprazole depends on whether it is purchased over the counter or by prescription, as over the counter medications are often more expensive because of the convenience associated with their purchase. The cash price for a one-month supply of 40 mg capsules is approximately 57 dollars when purchased by prescription, while 20 mg capsules would cost 26 dollars for a one month supply. The over the counter version of the medication is generally sold in bottles of 14 pills, as they are intended to be taken for no more than two weeks at a time.  Omeprazole is covered by most insurance plans, including Medicare and Medicaid, as well as most commercial insurance programs. However, insurance may not always offer the best prices on prescription drugs. Pharmacy discount card programs like USA Rx also offer savings on all FDA-approved brand name and generic medications, including omeprazole, and patients can sign up for free. 

What Benefits Are Associated With Omeprazole?

Proton pump inhibitors like omeprazole work differently to control acid reflux than faster-acting medications like antacids. There are several benefits associated with omeprazole’s ability to control acid production over an extended period of time:

  • Blocks the action of the majority of the stomach pumps that produce acid
  • Reduces the amount of stomach acid that causes heartburn
  • Relief from heartburn symptoms lasts up to 24 hours when taking one pill per day
  • Affordable medication that is accessible for most people
  • Available over the counter at a strength appropriate to control heartburn that occurs for up to two weeks every four months

What Risks Are Associated With Omeprazole?

Proton pump inhibitors like omeprazole do have some risks associated with long term use of the medication. Use of PPIs for a prolonged period of time (longer than the indicated dosing period) may increase the risk of the following conditions:

  • Bone weakening conditions, such as osteoporosis, leading to bone fractures in the spine and wrist in postmenopausal women, particularly when taken for a year or more at a high dose
  • Nutritional deficiencies, such as vitamin B-12 and magnesium deficiencies
  • Cutaneous lupus erythematosus (CLE) and systemic lupus erythematosus (SLE) 
  • Fundic gland polyps
  • Kidney disease and other problems
  • Bacterial inflammation of the colon (Clostridium difficile-associated diarrhea) due to disruption of the gut microbiome
  • Pneumonia
  • Heart-related conditions and cardiovascular issues

Some groups of people are considered more likely to experience negative effects associated with the long term use of PPIs. Risk factors include:

  • Being of Asian descent, as the body may require a different dosage due to a longer length of time needed to process PPIs
  • Medical conditions like liver disease
  • History of low magnesium levels
  • Being pregnant or planning to become pregnant
  • Breastfeeding

What Common Side Effects Are Associated With Omeprazole?

Side effects associated with omeprazole are fairly uncommon and most do not require medical attention. However, some can be serious. Possible side effects associated with omeprazole that do not normally require medical attention include:

  • Body aches or pain
  • Constipation
  • Diarrhea or loose stools
  • Dizziness
  • Gas
  • Loss of voice
  • Nasal congestion
  • Sneezing
  • Chest pain
  • Cough
  • Difficulty with breathing
  • Ear congestion
  • Heartburn
  • Muscle pain
  • Runny nose
  • Unusual drowsiness

Serious side effects associated with omeprazole are rare, but they can occur. Patients should seek medical advice if they experience any of the following adverse effects or allergic reactions while taking omeprazole:

  • Back, leg, or stomach pain
  • Blisters
  • Chills
  • Difficult, burning, or painful urination
  • Frequent urge to urinate
  • Frequent heartburn
  • Itching, skin rash
  • Loss of appetite
  • Pain
  • Redness, tenderness, itching, burning or peeling of the skin
  • Sores, ulcers, or white spots on the lips, in the mouth, or on the genitals
  • Unusual tiredness or weakness
  • Bleeding or crusting sores on the lips
  • Bloody or cloudy urine
  • Continuing ulcers or sores in the mouth
  • Fever
  • The feeling of discomfort or illness
  • Joint pain
  • Muscle aches or cramps
  • Red or irritated eyes
  • Sore throat
  • Unusual bleeding or bruising

Are There Any Drug Interactions Associated With Omeprazole?

Certain drugs and supplements should not be taken with Omeprazole. These medications include:

  • Clopidogrel
  • Nelfinavir
  • Rilpivirine
  • St. John’s wort
  • Delavirdine
  • Rifampin
  • Risedronate

Other drugs may interact with Omeprazole but can be taken with them under certain conditions. Make sure to tell your medical professional if you are taking any of the following medications:

  • Amphetamine
  • Atazanavir
  • Bosentan
  • Cilostazol
  • Clozapine
  • Dextroamphetamine
  • Antifungal drugs
  • Iron
  • Mesalamine
  • Methylphenidate
  • Raltegravir
  • Tacrolimus
  • Voriconazole
  • Aripiprazole
  • Bisphosphonates
  • Carvedilol
  • Citalopram
  • Cyclosporine
  • Escitalopram
  • Fosphenytoin
  • Hydrocodone
  • Methotrexate
  • Phenytoin
  • Saquinavir
  • Warfarin or other vitamin K antagonists

Is Omeprazole Safe for Use in Pregnant and Breastfeeding Women?

GERD and acid reflux are especially common during pregnancy, with approximately 30 to 50 percent of women experiencing heartburn during their pregnancies. Omeprazole is an FDA Category C medication for pregnant women, meaning that the effects of the medication on developing fetuses has not been conclusively studied. However, all proton pump inhibitors besides omeprazole are categorized by the FDA as Category B medications, meaning they are safe for use during pregnancy, and there is ample data that suggest that omeprazole should be categorized similarly.   However, the manufacturer advises that each woman speaks with their doctor to determine if the benefit of taking omeprazole during pregnancy may outweigh the risk. Omeprazole is generally considered safe to use while breastfeeding, as studies have shown that while PPIs do pass through breast milk to a nursing infant, no negative side effects have been demonstrated, and the amount that passes through the breast milk is less than the prescribed dose given to infants of the same age. Some infants suffer from acid reflux and receive a small dose of Zantac as a treatment for the condition; the dose given to infants is less than the amount that passes through breast milk.

Published July 14th, 2020 by Bridget Reed
Fact Checked by Chris Riley

What is Tresiba?

What is The Best Time to Take Tresiba?

How Much Does Jardiance Cost?

Was this artical helpful?

Put drug prices & coupons in your pocket!

We'll text you a link to download our free Android or iPhone app