The Consequences of Excessively Taking Omeprazole

Omeprazole is a drug that belongs to the group of proton pump inhibitors (PPIs). They're very useful drugs for certain indications, although with prolonged use they can trigger adverse effects. Learn more in this article!
The Consequences of Excessively Taking Omeprazole
María Vijande

Reviewed and approved by the pharmacist María Vijande.

Written by María Vijande

Last update: 11 June, 2022

Excessively taking omeprazole and other proton pump inhibitors result in several mild adverse effects. However, in a small percentage, they aren’t so mild.

Omeprazole is a drug that belongs to the group of proton pump inhibitors (PPIs). This group of drugs exerts a potent inhibition on the acid secretion of the stomach, which gives them great therapeutic efficacy.

This way, they’re able to alleviate symptoms in patients suffering from gastroesophageal reflux or epigastric heartburn. However, they’re also useful in preventing potential drug-induced digestive bleeding.

Excessively taking of omeprazole

Due to their own effectiveness, excessively taking omeprazole and this type of drug has spread beyond their indications. They produce a profound inhibition of acidity that’s associated with effective symptomatic control and rapid healing of lesions.

However, these drugs have potential adverse effects. Although they’re infrequent and generally mild, in some cases serious alterations may occur. For this reason, studies have shown that chronic use of omeprazole isn’t completely harmless.

Adverse effects of excessively taking omeprazole

The most frequent adverse effects include:

  • Headache and dizziness
  • Nausea and diarrhea
  • Abdominal pain
  • Constipation and flatulence
  • Skin rash

Other less frequent adverse effects, but which have been associated with long-term consumption, are related to the loss of the defensive barrier function of the stomach acid. This adverse effect favors changes in the intestinal flora with bacterial overgrowth. There are data indicating that it could favor Clostridium difficile infection.

There are also data on an increased incidence of Candida infection. The associations with a higher prevalence of pneumonia aren’t completely clear, so we need researchers to conduct more studies to confirm this. In addition, these studies have to be more thorough.

A image of stomach acid
Although used for gastroesophageal reflux, omeprazole can cause similar symptoms as an adverse effect.

Alterations in the absorption and metabolism of some substances

The abuse of omeprazole, with the consequent hypochlorhydria, is considered a predisposing factor to alterations in the absorption and metabolism of some substances. There are data indicating that hypochlorhydria is associated with difficulty in the absorption of vitamin B12.

Specialists have observed that there’s an increased risk of fractures in chronic omeprazole users. However, they haven’t yet proved that it’s associated with alterations in calcium absorption or a higher prevalence of osteoporosis.
Excess gastrin secretion, which is produced by the reduction of gastric acidity, has been related to a possible predisposition to develop gastric or pancreatic cancer. However, no data associates omeprazole abuse with an increase in the incidence of these neoplasms.

However, you need to know that in some people it can lead to rare reactions such as:

  • Hypomagnesemia
  • Interstitial nephritis
  • Chronic renal damage
  • Rhabdomyolysis
A bottle of medicine pills

Indications for prolonged treatment with omeprazole

To avoid abuse of omeprazole and any drug, it’s important to know its real indications. The list of indications for treatment with proton pump inhibitors is very long, but in most cases, they’re for a limited time.

The main indications for chronic use of omeprazole are those in which there’s a chronic acid-related disease that requires its suppression such as:

  • Esophagitis
  • Gastroesophageal reflux disease that recurs when treatment is discontinued
  • Barrett’s esophagus: considered pre-cancerous
  • Zollinger Ellison’s disease

In some of them, such as Barret’s esophagus, patients can use omeprazole chronically and it’s very safe. Doctors also indicate chronic use in patients who present a high risk of digestive bleeding, such as older adults or those who have suffered previous bleeding.


Omeprazole and other proton pump inhibitors are highly effective and safe drugs in the treatment of gastric acid-related diseases. They’re also useful in the prevention of gastrointestinal bleeding.

However, you should be aware that most of the indications for treatment with omeprazole don’t exceed 6-8 weeks of treatment. Taking it for more than that time is rare, has precise indications, and can end up with adverse effects.


All cited sources were thoroughly reviewed by our team to ensure their quality, reliability, currency, and validity. The bibliography of this article was considered reliable and of academic or scientific accuracy.

  • Molero Gómez, R., Sacristán de Lama, M. P., López Arranz, C., Mangues Bafalluy, I., Socias Manzano, M. S., & Piñeiro Corrales, G. (1997). Utilización Terapéutica del Omeprazol. Sociedad Española de Farmacia Hospitalaria.

  • Callejas Díaz, A., Montero Hernández, E., Gil Navarro, M., Tutor-Ureta, P., Yebra Bango, M., & Vargas Núñez, J. A. (2011). Omeprazol e hipomagnesemia. Revista Clinica Espanola.

  • Sánchez, L. J., Nombela, A. M., Velázquez, C. B., Hernández, S. H., & Carretón, M. a. J. A. (2016). Efectos adversos del consumo crónico de omeprazol. FMC Formacion Medica Continuada En Atencion Primaria.

This text is provided for informational purposes only and does not replace consultation with a professional. If in doubt, consult your specialist.