Lansoprazole can cause side effects, which may be mild or, in rare cases, serious. Common side effects include:
- headache
- diarrhea
- nausea
- constipation
- stomach pain
- dizziness
These symptoms are usually mild and often disappear after you stop taking the medication or as your body adjusts. However, if they persist or worsen, contact your doctor[1][4][5].
Less common or rare side effects include:
- joint pain
- increased or decreased appetite
- vomiting
- anxiety or nervousness
- blurred vision
- muscle pain
- rectal bleeding
- unusual bleeding or bruising
- mental depression
If you develop any of these symptoms, seek medical advice[2].
Some serious side effects require immediate medical attention. Contact your doctor or emergency services if you experience:
- rash; hives; itching; swelling of the face, lips, mouth, throat, or tongue; difficulty breathing or swallowing; or tightness in the throat (signs of a severe allergic reaction)
- blistering, peeling, or bleeding skin; or sores on the lips, nose, mouth, or genitals
- fever, swollen glands, or flu-like symptoms
- severe diarrhea, especially if it’s watery or bloody
- irregular, fast, or pounding heartbeat
- muscle spasms, uncontrollable shaking, or seizures
- new or worsening joint pain with a red skin rash, especially after exposure to sunlight
These could be signs of serious reactions such as Stevens-Johnson Syndrome, Toxic Epidermal Necrolysis, kidney problems, or severe allergic responses[1][3][4][6].
Long-term use risks:
- Increased risk of bone fractures (hip, wrist, spine), especially in people taking high doses for longer than a year
- Development of fundic gland polyps (stomach lining growths)
- Possible decrease in magnesium or vitamin B12 levels after prolonged use
Your doctor may recommend monitoring these risks if you require long-term treatment[1][5][6].
If you have any unusual or persistent symptoms while taking lansoprazole, consult your healthcare provider immediately[1].