Applies to all Prevacid dosage forms. Lansoprazole (the active ingredient contained in Prevacid) may cause unwanted side effects that require medical attention.

Severity: Major

If any of the following side effects occur while taking lansoprazole, check with your doctor immediately:

More common:

  • Diarrhea
  • skin rash or itching

Less common:

  • Abdominal or stomach pain
  • increased or decreased appetite
  • joint pain
  • nausea
  • vomiting

Rare:

  • Anxiety
  • cold or flu-like symptoms
  • constipation
  • increased cough
  • mental depression
  • muscle pain
  • rectal bleeding
  • unusual bleeding or bruisin

Incidence not known:

  • Abdominal or stomach tenderness
  • back or leg pains
  • bleeding gums
  • blistering, peeling, or loosening of the skin
  • bloating
  • bloody, black, or tarry stools
  • change in mental status
  • chest pain
  • chills
  • clay colored stools
  • cough or hoarseness
  • dark or bloody urine
  • difficulty with swallowing
  • drowsiness
  • fast heartbeat
  • fever
  • general body swelling
  • high fever
  • hives
  • indigestion
  • loss of appetite
  • lower back or side pain
  • mood or mental changes
  • muscle spasms (tetany) or twitching seizures
  • nosebleeds
  • painful or difficult urination
  • pains in the stomach, side, or abdomen, possibly radiating to the back
  • pale skin
  • pinpoint red spots on the skin
  • puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue
  • red, irritated eyes
  • red skin lesions, often with a purple center
  • seizures
  • sore throat
  • sores, ulcers, or white spots on the lips or in the mouth
  • swelling of the feet or lower legs
  • swollen or painful glands
  • tightness in the chest
  • trembling
  • unusual tiredness or weakness
  • yellow eyes or skin

Severity: Minor

Some lansoprazole side effects may not need any medical attention. As your body gets used to the medicine these side effects may disappear. Your health care professional may be able to help you prevent or reduce these side effects, but do check with them if any of the following side effects continue, or if you are concerned about them:

More common:

  • Dizziness
  • headache

Less common:

  • Bleeding, blistering, burning, coldness, or discoloration of the skin
  • mild nausea

Rare:

  • Acid or sour stomach
  • bad, unusual or unpleasant (after) taste
  • belching
  • burning, crawling, itching, numbness, prickling, “pins and needles”, or tingling feelings
  • change in taste
  • feeling faint, dizzy, or lightheaded
  • feeling of heat or warmth
  • flushing or redness of the skin, especially on the face and neck
  • mild diarrhea
  • mild headache
  • mild vomiting
  • stomach discomfort or upset
  • sweating

Incidence not known:

  • Decrease in passing urine (dribbling)
  • decrease in the frequency of urination
  • decrease in urine volume
  • difficulty with speaking