Complete Side Effects Profile for Omeprazole
Common Side Effects (1 in 10 people or more)
The most frequently reported side effects of omeprazole are generally mild and may include headaches, which affect approximately 7% of patients. Gastrointestinal effects such as stomach pain, diarrhoea, constipation, wind, and feeling sick are also common. These symptoms often improve as your body adjusts to treatment, typically within the first few weeks of starting omeprazole.
Uncommon Side Effects (1 in 100 people)
Less common effects include dizziness, dry mouth, insomnia, and skin reactions such as itchy rash. Some patients experience swelling of feet and ankles, blood test changes affecting liver function, or increased sweating. Feeling drowsy or having disturbed sleep patterns has also been reported, though these effects usually resolve with continued treatment.
Rare but Serious Side Effects
Severe kidney problems, though rare, can occur with long-term omeprazole use. Warning signs include passing little or no urine, swollen ankles or face, and feeling tired or short of breath. Low magnesium levels (hypomagnesaemia) may develop after prolonged treatment, potentially causing muscle spasms, irregular heartbeat, or fits. Joint pain affecting multiple areas of the body has been reported in some cases.
Long-term Safety Considerations
Extended omeprazole use may increase the risk of bone fractures, particularly in the hip, wrist, and spine, especially in patients over 50 or those taking high doses. Vitamin B12 deficiency can develop with prolonged treatment, potentially causing tiredness, weakness, or neurological symptoms. Some studies suggest a possible increased risk of stomach infections, as reduced acid levels may affect natural bacterial balance.
Drug Interactions and Precautions
Omeprazole can interact with medications such as warfarin, clopidogrel, and some antifungal treatments. EverydayMeds offers alternative acid reflux treatments including lansoprazole, pantoprazole, and esomeprazole for patients who experience problematic side effects with omeprazole. Our qualified pharmacists can review your medications to identify potential interactions and recommend suitable alternatives when appropriate.
When to Seek Medical Advice
Contact your healthcare provider if you experience persistent or worsening side effects, signs of allergic reaction including difficulty breathing or facial swelling, or symptoms suggesting serious complications. Regular monitoring may be recommended for long-term users, particularly older patients or those with existing kidney or liver conditions.
