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Lansoprazole Side Effects

For the Consumer

Applies to lansoprazole: oral capsule delayed release, oral packet, oral powder for suspension, oral tablet disintegrating delayed release

In addition to its needed effects, some unwanted effects may be caused by lansoprazole. In the event that any of these side effects do occur, they may require medical attention.

Severity: Major

You should check with your doctor immediately if any of these side effects occur when taking lansoprazole:

More common:
  • Diarrhea
  • skin rash or itching
Less common:
  • Abdominal or stomach pain
  • increased or decreased appetite
  • joint pain
  • nausea
  • vomiting
  • Anxiety
  • cold or flu-like symptoms
  • constipation
  • increased cough
  • mental depression
  • muscle pain
  • rectal bleeding
  • unusual bleeding or bruising
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 of the side effects that can occur with lansoprazole may not need medical attention. As your body adjusts to the medicine during treatment these side effects may go away. Your health care professional may also be able to tell you about ways to reduce or prevent some of these side effects. If any of the following side effects continue, are bothersome or if you have any questions about them, check with your health care professional:

More common:
  • Dizziness
  • headache
Less common:
  • Bleeding, blistering, burning, coldness, or discoloration of the skin
  • mild nausea
  • 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

For Healthcare Professionals

Applies to lansoprazole: compounding powder, intravenous powder for injection, oral delayed release capsule, oral granule for reconstitution, oral suspension, oral tablet disintegrating


Oncologic side effects have not been reported in humans. Drugs which increase gastric pH would be anticipated to stimulate release of gastrin. Animal studies have demonstrated an increase in plasma gastrin concentrations following the administration of lansoprazole. In addition, lifelong high-dose animal studies have revealed a dose-related increase in the incidence of gastric enterochromaffin-like (ECL) cell carcinoids (especially in female rats). However, to date, human studies of up to 1 year have not found any suggestion of gastric carcinoid formation due to lansoprazole use.[Ref]


Case series report of lansoprazole-associated microscopic colitis was confirmed by pathology studies of random biopsies of colon in six patients who developed chronic watery diarrhea. Patients completely recovered within 4 to 10 days after discontinuation of therapy.[Ref]

Gastrointestinal side effects have included diarrhea (3.2% to 11.6%), abdominal pain (1.8% to 4.3%), and nausea (1.4%). Vomiting and constipation have been reported less often. At least 6 cases of microscopic colitis have been reported. Pancreatitis has also been reported during postmarketing experience.[Ref]

Nervous system

Nervous system side effects have included headache in as many as 23% of patients (although most investigators have reported a much lower incidence), dizziness, and pain. Speech disorder has also been reported during postmarketing experience.[Ref]

The manufacturer reports that headache occurs more often in placebo treated patients than in lansoprazole treated patients.[Ref]


Dermatologic side effects have included skin rash in 4.3% of patients. Rarely, erythema multiforme has been reported.[Ref]


Hepatic side effects have included elevations of gamma-glutamyltransferase (GGT) and other liver function tests in a small number of patients. Elevated alanine aminotransferase (ALT) levels have been reported within a month after initiation of treatment with lansoprazole. Hepatotoxicity has also been reported in postmarketing experience.[Ref]


Respiratory side effects have included rhinitis and pharyngitis in 1% to 2% of patients. Cough and influenza-like symptoms have been reported less frequently.[Ref]


Psychiatric side effects including depression and anxiety have been extremely uncommon.[Ref]


Genitourinary side effects have been reported rarely. Impotence has been reported in some patients and a poorly described "testes disorder" has been reported in one patient. Interstitial nephritis and urinary retention have also been reported in postmarketing experience.[Ref]


Cardiovascular side effects have been reported rarely. These have included angina, myocardial infarction, hypertension, and hypotension in patients taking lansoprazole but the etiology of these cardiovascular problems was not specifically attributed to lansoprazole. Necrotizing arteritis has been reported in dogs. However, the clinical implications for human use have not been determined. In humans, one case of ischemic optic neuropathy has been tentatively associated with the use of the related drug omeprazole.[Ref]


Hypersensitivity side effects have rarely included toxic epidermal necrolysis. A few cases of eosinophilia have been reported and a single case of glottis edema. Stevens-Johnson syndrome and anaphylactic/anaphylactoid reactions have also been reported during postmarketing experience.[Ref]


An increased risk of hip fracture has been reported in a recent cohort study with information on patients in the United Kingdom (1987 to 2003). The risk of hip fracture was significantly increased among patients prescribed long-term high dose PPIs.

A 50-year-old white woman developed severe myalgia one week after starting lansoprazole. The patient also was found to have eosinophilia. The severity of pain worsened to the point where she had to quit her job and could not sleep at night. The patient eventually recovered after stopping lansoprazole and being treated with prednisone.

A 46-year-old woman who had undergone near total thyroidectomy six years earlier and fully compliant with her thyroid medication was diagnosed with tetany coincident with lansoprazole therapy. She had undergone two weeks of treatment with lansoprazole 30 mg daily. Her signs and symptoms responded immediately to intravenous administration of 10% calcium gluconate (20 mL) over 20 minutes; oral calcium carbonate, 2 g; and 0.25 mg calcitriol, and she fully recovered. Hypocalcemia is known to occur in subtotal thyroidectomy and in achlorhydria.[Ref]

Musculoskeletal side effects have included muscle spasm (tetany), arthralgia, aggravation of arthritis, arthropathy, cramps, fibromyalgia syndrome, hernia, hypertonia, polymyalgia rheumatica, and back pain. Myalgia and bone fracture have also been reported.[Ref]


An 85-year-old man experienced thrombocytopenia after receiving a second dose of lansoprazole 60 mg while in the hospital. His platelet count returned to normal values a few days after the drug was discontinued.[Ref]

Hematologic side effects have included decreased hemoglobin. Agranulocytosis, aplastic anemia, hemolytic anemia, leukopenia, neutropenia, pancytopenia, thrombocytopenia, and thrombocytopenic purpura have been reported during postmarketing experience.[Ref]


Other side effects including increased blood potassium, increased blood urea, crystal urine present, and positive fecal occult blood have been reported.[Ref]


FDA warns that prescription proton pump inhibitor (PPI) drugs may cause low serum magnesium levels (hypomagnesemia) if taken for prolonged periods of time (in most cases, longer than one year). Patients who develop hypomagnesemia may experience seizures, dizziness, abnormal or fast heart beat, or skipped heartbeat, jitteriness, jerking movements or tremors, muscle weakness, spasms of the hands and feet, cramps or muscle aches, and spasm of the voice box.


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4. Hawkey CJ, Long RG, Bardhan KD, Wormsley KG, Cochran KM, Christian J, Moules IK "Improved symptom relief and duodenal ulcer healing with lansoprazole, a new proton pump inhibitor, compared with ranitidine." Gut 34 (1993): 1458-62

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8. Feldman M, Harford WV, Fisher RS, Sampliner RE, Murray SB, Greski-Rose PA, Jennings DE "Treatment of reflux esophagitis resistant to H2-receptor antagonists with lansoprazole, a new H+/K(+)-ATPase inhibitor: a controlled, double-blind study. Lansoprazole Study Group." Am J Gastroenterol 88 (1993): 1212-7

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12. Hatlebakk JG, Berstad A, Carling L, Svedberg LE, Unge P, Ekstrom P, Halvorsen L, Stallemo A, Hovdenak N, Trondstad R, et al "Lansoprazole versus omeprazole in short-term treatment of reflux oesophagitis. Results of a Scandinavian multicentre trial." Scand J Gastroenterol 28 (1993): 224-8

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17. Takeda K, Nakamoto M, Nishihara G, Ueno K, Yasunaga C, Matsuo K, Urabe M, Goya T "Severe eosinophilia related with lansoprazole in a hemodialysis patient." Nephron 79 (1998): 115-6

18. Roldan FP, Rios ILD, Quinzanos ER "Lansoprazole and glottis edema." Am J Gastroenterol 94 (1999): 1995

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20. Yang YX, Lewis JD, Epstein S, Metz DC "Long-term proton pump inhibitor therapy and risk of hip fracture." JAMA 296 (2006): 2947-53

21. Subbiah V, Tayek JA "Tetany secondary to the use of a proton-pump inhibitor." Ann Intern Med 137 (2002): 219

22. Zlabek JA, Anderson CG "Lansoprazole-induced thrombocytopenia." Ann Pharmacother 36 (2002): 809-11

Not all side effects for lansoprazole may be reported. You should always consult a doctor or healthcare professional for medical advice. Side effects can be reported to the FDA here.

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