Medically reviewed by Jessica Swirble, PharmD
Last updated on 5/16/2024

Drug Information | Side Effects | Use & Dosage | Request a Prescription

The use of omeprazole can lead to various side effects in some individuals.

Common mild side effects of omeprazole use include:

• Headache
  
• Diarrhea or constipation
  
• Nausea or upset stomach
  
• Vomiting
  
• Gas or bloating
  
• Dizziness
  
• Rash
  
• Cough
  
  

More severe side effects of omeprazole use can include:

• Severe stomach pain, nausea, or vomiting
  
• Kidney problems (such as changes in urine output)
  
• Severe diarrhea, especially if it is watery or bloody
  
• Unusual weight gain or swelling
  
• Low magnesium levels (leading to rapid heartbeat, jitteriness, muscle cramps, muscle spasms, or weakness)
  
• Lupus-like symptoms (such as rash on the nose and cheeks, new or worsening joint pain)
  
  

If you experience any severe or concerning side effects while taking omeprazole, contact your healthcare provider right away.

Tell your healthcare provider about any existing medical conditions, allergies, or other medications you are taking before starting treatment with omeprazole. This includes prescription drugs, over-the-counter medications, and dietary supplements, as they may interact with omeprazole.

Tell your provider if you are taking these medications or supplements:

• Anticoagulants (such as warfarin)
  
• Antiplatelet medications
  
• Antifungal medications
  
• Antibiotics
  
• HIV medications
  
• Anti-seizure medications
  
• Medications for depression
  
• Other stomach acid reducers
  
• Iron supplements
  
• St John’s wort
  
  

You should also mention medical conditions such as:

• Liver disease
  
• Osteoporosis or low bone mineral density
  
• Low magnesium or vitamin B12 levels
  
• Autoimmune disorders such as lupus
  
• Stomach cancer
  
  

If you are pregnant, planning to become pregnant, or breastfeeding, consult your healthcare provider before using omeprazole to assess potential risks and benefits.

Take omeprazole exactly as prescribed by your healthcare provider. Do not exceed the recommended dose or duration of treatment.

Omeprazole should be taken before meals, preferably in the morning. Swallow the capsules whole; do not crush, chew, or open them.

Avoid alcohol and foods that may trigger your symptoms. Be mindful of your body’s response to different dietary choices and activities.

Store omeprazole at room temperature, away from moisture and heat. Keep it out of reach of children.

In case of an omeprazole overdose, seek medical attention immediately. Symptoms of overdose may include confusion, drowsiness, blurred vision, fast or pounding heartbeats, nausea, vomiting, sweating, flushing, headache, dry mouth, and a faint feeling. If you suspect an overdose, contact the poison control helpline at 1-800-222-1222 or call emergency services.