Prilosec Side Effects

The most common side effects of Prilosec (omeprazole) are headaches and abdominal pain. Rarely, serious side effects may occur, including liver and kidney damage. Prilosec may also lead to a higher risk of fractures if taken long-term. Ask your doctor about Prilosec side effects before taking it.

Last Modified: September 7, 2023
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Common Prilosec Side Effects

Common side effects of Prilosec (omeprazole) include headache and intestinal issues. Prilosec is a proton-pump inhibitor medication used for heartburn, gastroesophageal reflux disease, peptic ulcer disease, Zollinger-Ellison syndrome and other conditions. Prilosec relieves symptoms by reducing stomach acid.

The most common side effects are:
  • Headache (7%)
  • Abdominal pain (5%)
  • Nausea (4%)
  • Diarrhea (4%)
  • Vomiting (3%)
  • Flatulence (3%)
  • Constipation (2%)

Using Prilosec long-term may cause vitamin B12 and magnesium deficiencies.

Serious Side Effects

Serious side effects of Prilosec and other proton pump inhibitors may occur. Prilosec may lead to a higher risk of fractures if taken long-term.

Other serious side effects include:
  • Allergic reactions
  • Bone fractures
  • Growth in stomach lining known as fundic gland polyps
  • Infection of the gut known as Clostridioides difficile (C. diff) associated diarrhea
  • Joint pain
  • Kidney damage
  • Magnesium deficiency
  • Skin reactions
  • Vitamin B12 deficiency

Children and infants should only take Prilosec if prescribed by their pediatrician.

Rare Condition Associated With Prilosec

Prilosec is associated with a condition known as subacute cutaneous lupus erythematosus. People develop a rash with ringed red lesions on the skin, sometimes along with scaly patches that have distinct edges. Exposure to the sun worsens the rash. People with the condition have also reported joint pain. The condition usually resolves three months after stopping Prilosec.

Long-Term Side Effects of Prilosec

Taking high doses of Prilosec for long periods of time may lead to more serious side effects. Research has linked Prilosec to chronic kidney disease, renal failure and kidney injuries such as interstitial nephritis. People have filed Prilosec lawsuits for kidney or liver injuries.

Prilosec increases the risk of wrist, hip or spine fractures if used long-term. Researchers are not sure of the exact reason for this increased risk but recommend osteoporosis medication to manage Prilosec’s effect on bones.

Prilosec Overdose

It is essential to take Prilosec only for the length of time your doctor recommends and only in the prescribed dose. If you have questions about how much Prilosec is safe, talk to your doctor.

It’s possible to overdose on Prilosec.

Signs of a Prilosec overdose include:
  • Blurred vision
  • Confusion
  • Drowsiness
  • Dry mouth
  • Fast or pounding heartbeat
  • Flushing of the skin
  • Headache
  • Nausea and vomiting

If you take Prilosec and are experiencing one or more of these symptoms, contact the Poison Control Helpline at 1-800-222-1222. You can also get help online at Call 911 if you are experiencing a medical emergency after taking Prilosec.

Before Taking Prilosec

Your doctor may require lab tests before prescribing Prilosec. Only take Prilosec for as long as your doctor recommends. If you’re buying it over the counter, follow the label recommendations.

People with a history of hypersensitivity to omeprazole should not take Prilosec. Talk to your doctor before taking Prilosec if you have liver problems or are due for an endoscopy. In addition, you should not take omeprazole with heart medications, antifungal medications, methotrexate, HIV medicines or cilostazol.

Please seek the advice of a medical professional before making health care decisions.