What is Prevacid (lansoprazole)?

Prevacid (lansoprazole) is a proton pump inhibitor (PPI) which blocks the production of acid by the stomach used to treat conditions such as ulcers, gastroesophageal reflux disease (GERD) and Zollinger-Ellison syndrome that are caused by stomach acid. 

Prevacid, like other proton-pump inhibitors, blocks the enzyme in the wall of the stomach that produces acid. By blocking the enzyme, the production of acid is decreased, and this allows the stomach and esophagus to heal. Prevacid is available over-the-counter (OTC). 

Drug interactions of Prevacid include other drugs whose absorption may be affected by stomach acidity. Prevacid and other PPIs that reduce stomach acid also reduce the absorption and concentration in blood of ketoconazole and increase the absorption and concentration in blood of digoxin. This may lead to reduced effectiveness of ketoconazole or increased digoxin toxicity, respectively. 

Prevacid may increase blood levels of methotrexate and tacrolimus

Proton pump inhibitors may also increase the action of warfarin, increasing the risk of bleeding. 

Use of Prevacid in pregnant women has not been adequately evaluated. Prevacid has not been studied in nursing women. Consult your doctor before breastfeeding.

What are the side effects of Prevacid?

What are the common side effects of Prevacid?

Common side effects of Prevacid include

What are the serious side effects of Prevacid?

Serious side effects of Prevacid include

  • increased risk of Clostridium difficile infection;
  • increased risk of osteoporosis-related fractures of the hip, wrist, or spine with high doses and long-term use (1 year or longer);
  • reduced absorption of vitamin B12 (cyanocobalamin);
  • low levels of magnesium (hypomagnesemia) with long-term use; and
  • increased risk of heart attacks with long-term use.

Is Prevacid addictive?

No information provided

What drugs interact with Prevacid?

Tables 2 and 3 include drugs with clinically important drug interactions and interaction with diagnostics when administered concomitantly with Prevacid or Prevacid SoluTab and instructions for preventing or managing them.

Consult the labeling of concomitantly used drugs to obtain further information about interactions with PPIs.

Table 2. Clinically Relevant Interactions Affecting Drugs Co-Administered with Prevacid orPrevacid SoluTab and Interactions with Diagnostics

Clinical Impact: The effect of PPIs on antiretroviral drugs is variable. The clinical importance and the mechanisms behind these interactions are not always known.
  • Decreased exposure of some antiretroviral drugs (e.g., rilpivirine, atazanavir, and nelfinavir) when used concomitantly with lansoprazole may reduce antiviral effect and promote the development of drug resistance.
  • Increased exposure of other antiretroviral drugs (e.g., saquinavir) when used concomitantly with lansoprazole may increase toxicity of the antiretroviral drugs.
  • There are other antiretroviral drugs which do not result in clinically relevant interactions with lansoprazole.

Rilpivirine-containing products: Concomitant use with Prevacid or Prevacid SoluTab is contraindicated. See prescribing information.

Atazanavir: See prescribing information for atazanavir for dosing information.

Nelfinavir: Avoid concomitant use with Prevacid or Prevacid SoluTab. See prescribing information for nelfinavir.

Saquinavir:See the prescribing information for saquinavir and monitor for potential saquinavir toxicities.

Other antiretrovirals: See prescribing information.

Clinical Impact: Increased INR and prothrombin time in patients receiving PPIs and warfarin concomitantly. Increases in INR and prothrombin time may lead to abnormal bleeding and even death.
Intervention: Monitor INR and prothrombin time. Dose adjustment of warfarin may be needed to maintain target INR range. See prescribing information for warfarin.
Clinical Impact: Concomitant use of PPIs with methotrexate (primarily at high dose) may elevate and prolong serum concentrations of methotrexate and/or its metabolite hydroxymethotrexate, possibly leading to methotrexate toxicities. No formal drug interaction studies of high-dose methotrexate with PPIs have been conducted.
Intervention: A temporary withdrawal of Prevacid or Prevacid SoluTab may be considered in some patients receiving high-dose methotrexate.
Clinical Impact: Potential for increased exposure of digoxin.
Intervention: Monitor digoxin concentrations. Dose adjustment of digoxin may be needed to maintain therapeutic drug concentrations. See prescribing information for digoxin.
Clinical Impact: Increased clearance of theophylline.
Intervention: Individual patients may require additional titration of their theophylline dosage when Prevacid or Prevacid SoluTab is started or stopped to ensure clinically effective blood concentrations.
Drugs Dependent on Gastric pH for Absorption (e.g., iron salts, erlotinib, dasatinib, nilotinib,mycophenolate mofetil, ketoconazole/itraconazole)
Clinical Impact: Lansoprazole can reduce the absorption of other drugs due to its effect on reducing intragastric acidity.

Mycophenolate mofetil (MMF): Co-administration of PPIs in healthy subjects and in transplant patients receiving MMF has been reported to reduce the exposure to the active metabolite, mycophenolic acid (MPA), possibly due to a decrease in MMF solubility at an increased gastric pH. The clinical relevance of reduced MPA exposure on organ rejection has not been established in transplant patients receiving Prevacid and MMF.

Use Prevacid and Prevacid SoluTab with caution in transplant patients receiving MMF. See the prescribing information for other drugs dependent on gastric pH for absorption.

Combination Therapy with Clarithromycin and Amoxicillin
Clinical Impact: Concomitant administration of clarithromycin with other drugs can lead to serious adverse reactions, including potentially fatal arrhythmias, and are contraindicated. Amoxicillin also has drug interactions.
  • See Contraindications and Warnings and Precautions in prescribing information for clarithromycin.
  • See Drug Interactions in prescribing information for amoxicillin.
Clinical Impact: Potentially increased exposure of tacrolimus, especially in transplant patients who are intermediate or poor metabolizers of CYP2C19.
Intervention: Monitor tacrolimus whole blood trough concentrations. Dose adjustment of tacrolimus may be needed to maintain therapeutic drug concentrations. See prescribing information for tacrolimus.
Interactions with Investigations of Neuroendocrine Tumors
Clinical Impact: CgA levels increase secondary to PPI-induced decreases in gastric acidity. The increased CgA level may cause false positive results in diagnostic investigations for neuroendocrine tumors.
Intervention: Temporarily stop Prevacid or Prevacid SoluTab treatment at least 14 days before assessing CgA levels and consider repeating the test if initial CgA levels are high. If serial tests are performed (e.g., for monitoring), the same commercial laboratory should be used for testing, as reference ranges between tests may vary.
Interaction with Secretin Stimulation Test
Clinical Impact: Hyper-response in gastrin secretion in response to secretin stimulation test, falsely suggesting gastrinoma.
Intervention: Temporarily stop Prevacid or Prevacid SoluTab treatment at least 28 days before assessing to allow gastrin levels to return to baseline.
False Positive Urine Tests for THC
Clinical Impact: There have been reports of false positive urine screening tests for tetrahydrocannabinol (THC) in patients receiving PPIs.
Intervention: An alternative confirmatory method should be considered to verify positive results.

Table 3. Clinically Relevant Interactions Affecting Prevacid or Prevacid SoluTab When Co-Administered with Other Drugs

CYP2C19 OR CYP3A4 Inducers
Clinical Impact: Decreased exposure of lansoprazole when used concomitantly with strong inducers.
Intervention: St John’s Wort, rifampin: Avoid concomitant use with Prevacid or Prevacid SoluTab.
Ritonavir-containing products: See prescribing information.
CYP2C19 or CYP3A4 Inhibitors
Clinical Impact: Increased exposure of lansoprazole is expected when used concomitantly with strong inhibitors.
Intervention: Voriconazole: See prescribing information.
Clinical Impact: Decreased and delayed absorption of lansoprazole.
Intervention: Take Prevacid or Prevacid SoluTab at least 30 minutes prior to sucralfate.

Prevacid side effects list for healthcare professionals

The following serious adverse reactions are described below and elsewhere in labeling:

Clinical Trials Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in clinical practice.

Worldwide, over 10,000 patients have been treated with Prevacid in Phase 2 or Phase 3 clinical trials involving various dosages and durations of treatment. In general, Prevacid treatment has been well-tolerated in both short-term and long-term trials.

The following adverse reactions were reported by the treating physician to have a possible or probable relationship to drug in 1% or more of Prevacid-treated patients and occurred at a greater rate in Prevacid-treated patients than placebo-treated patients in Table 1.

Table 1. Incidence of Possibly or Probably Treatment-Related Adverse Reactions in Short-Term, Placebo-Controlled Prevacid Studies

Body System/
Adverse Reaction
Body as a Whole
  Abdominal Pain 2.1 1.2
Digestive System
  Constipation 1.0 0.4
  Diarrhea 3.8 2.3
  Nausea 1.3 1.2

Headache was also seen at greater than 1% incidence but was more common on placebo. The incidence of diarrhea was similar between patients who received placebo and patients who received 15 and 30 mg of Prevacid, but higher in the patients who received 60 mg of Prevacid (2.9, 1.4, 4.2, and 7.4%, respectively).

The most commonly reported possibly or probably treatment-related adverse event during maintenance therapy was diarrhea.

In the risk reduction study of Prevacid for NSAID-associated gastric ulcers, the incidence of diarrhea for patients treated with Prevacid, misoprostol, and placebo was 5, 22, and 3%, respectively.

Another study for the same indication, where patients took either a COX-2 inhibitor or lansoprazole and naproxen, demonstrated that the safety profile was similar to the prior study. Additional reactions from this study not previously observed in other clinical trials with Prevacid included

Additional adverse experiences occurring in less than 1% of patients or subjects who received Prevacid in domestic trials are shown below:

Body as a Whole – abdomen enlarged, allergic reaction, asthenia, back pain, candidiasis, carcinoma, chest pain (not otherwise specified), chills, edema, fever, flu syndrome, halitosis, infection (not otherwise specified), malaise, neck pain, neck rigidity, pain, pelvic pain

Cardiovascular Systemangina, arrhythmia, bradycardia, cerebrovascular accident/cerebral infarction, hypertension/hypotension, migraine, myocardial infarction, palpitations, shock (circulatory failure), syncope, tachycardia, vasodilation

Digestive System – abnormal stools, anorexia, bezoar, cardiospasm, cholelithiasis, colitis, dry mouth, dyspepsia, dysphagia, enteritis, eructation, esophageal stenosis, esophageal ulcer, esophagitis, fecal discoloration, flatulence, gastric nodules/fundic gland polyps, gastritis, gastroenteritis, gastrointestinal anomaly, gastrointestinal disorder, gastrointestinal hemorrhage, glossitis, gum hemorrhage, hematemesis, increased appetite, increased salivation, melena, mouth ulceration, nausea and vomiting, nausea and vomiting and diarrhea, gastrointestinal moniliasis, rectal disorder, rectal hemorrhage, stomatitis, tenesmus, thirst, tongue disorder, ulcerative colitis, ulcerative stomatitis

Endocrine System diabetes mellitus, goiter, hypothyroidism

Hemic and Lymphatic Systemanemia, hemolysis, lymphadenopathy

Metabolism and Nutritional Disorders – avitaminosis, gout, dehydration, hyperglycemia/hypoglycemia, peripheral edema, weight gain/loss

Musculoskeletal Systemarthralgia, arthritis, bone disorder, joint disorder, leg cramps, musculoskeletal pain, myalgia, myasthenia, ptosis, synovitis

Nervous System – abnormal dreams, agitation, amnesia, anxiety, apathy, confusion, convulsion, dementia, depersonalization, depression, diplopia, dizziness, emotional lability, hallucinations, hemiplegia, hostility aggravated, hyperkinesia, hypertonia, hypesthesia, insomnia, libido decreased/increased, nervousness, neurosis, paresthesia, sleep disorder, somnolence, thinking abnormality, tremor, vertigo

Respiratory System asthma, bronchitis, cough increased, dyspnea, epistaxis, hemoptysis, hiccup, laryngeal neoplasia, lung fibrosis, pharyngitis, pleural disorder, pneumonia, respiratory disorder, upper respiratory inflammation/infection, rhinitis, sinusitis, stridor

Skin and Appendages acne, alopecia, contact dermatitis, dry skin, fixed eruption, hair disorder, maculopapular rash, nail disorder, pruritus, rash, skin carcinoma, skin disorder, sweating, urticaria

Special Senses – abnormal vision, amblyopia, blepharitis, blurred vision, cataract, conjunctivitis, deafness, dry eyes, ear/eye disorder, eye pain, glaucoma, otitis media, parosmia, photophobia, retinal degeneration/disorder, taste loss, taste perversion, tinnitus, visual field defect

Urogenital System – abnormal menses, breast enlargement, breast pain, breast tenderness, dysmenorrhea, dysuria, gynecomastia, impotence, kidney calculus, kidney pain, leukorrhea, menorrhagia, menstrual disorder, penis disorder, polyuria, testis disorder, urethral pain, urinary frequency, urinary retention, urinary tract infection, urinary urgency, urination impaired, vaginitis

Postmarketing Experience

Additional adverse experiences have been reported since Prevacid and Prevacid SoluTab have been marketed. The majority of these cases are foreign-sourced and a relationship to Prevacid or Prevacid SoluTab has not been established. Because these reactions were reported voluntarily from a population of unknown size, estimates of frequency cannot be made. These events are listed below by COSTART body system.

Body as a Whole – anaphylactic/anaphylactoid reactions, systemic lupus erythematosus;

Digestive System – hepatotoxicity, pancreatitis, vomiting;

Hemic and Lymphatic System – agranulocytosis, aplastic anemia, hemolytic anemia, leukopenia, neutropenia, pancytopenia, thrombocytopenia, and thrombotic thrombocytopenic purpura;

Infections and InfestationsClostridium difficile-associated diarrhea;

Metabolism and Nutritional Disorders – hypomagnesemia; Musculoskeletal System – bone fracture, myositis;

Skin and Appendages – severe dermatologic reactions including erythema multiforme, Stevens-Johnson syndrome, toxic epidermal necrolysis (some fatal), cutaneous lupus erythematosus;

Special Senses – speech disorder;

Urogenital System – interstitial nephritis, urinary retention.

Combination Therapy With Amoxicillin And Clarithromycin

In clinical trials using combination therapy with Prevacid plus amoxicillin and clarithromycin, and Prevacid plus amoxicillin, no adverse reactions peculiar to these drug combinations were observed. Adverse reactions that have occurred have been limited to those that had been previously reported with Prevacid, amoxicillin, or clarithromycin.

Triple Therapy


The most frequently reported adverse reactions for patients who received triple therapy for 14 days were diarrhea (7%), headache (6%), and taste perversion (5%). There were no statistically significant differences in the frequency of reported adverse reactions between the 10 and 14 day triple therapy regimens. No treatment-emergent adverse reactions were observed at significantly higher rates with triple therapy than with any dual therapy regimen.

Dual Therapy

Prevacid/amoxicillin The most frequently reported adverse reactions for patients who received Prevacid three times daily plus amoxicillin three times daily dual therapy were diarrhea (8%) and headache (7%). No treatment-emergent adverse reactions were observed at significantly higher rates with Prevacid three times daily plus amoxicillin three times daily dual therapy than with Prevacid alone.

For information about adverse reactions with antibacterial agents (amoxicillin and clarithromycin) indicated in combination with Prevacid or Prevacid SoluTab, refer to the Adverse Reactions section of their prescribing information.

Laboratory Values

The following changes in laboratory parameters in patients who received Prevacid were reported as adverse reactions:

  • Abnormal liver function tests,
  • increased SGOT (AST),
  • increased SGPT (ALT),
  • increased creatinine,
  • increased alkaline phosphatase,
  • increased globulins,
  • increased GGTP,
  • increased/decreased/abnormal WBC,
  • abnormal AG ratio,
  • abnormal RBC,
  • bilirubinemia,
  • blood potassium increased,
  • blood urea increased,
  • crystal urine present,
  • eosinophilia,
  • hemoglobin decreased,
  • hyperlipemia,
  • increased/decreased electrolytes,
  • increased/decreased cholesterol,
  • increased glucocorticoids,
  • increased LDH,
  • increased/decreased/abnormal platelets,
  • increased gastrin levels and
  • positive fecal occult blood.

Urine abnormalities such as albuminuria, glycosuria, and hematuria were also reported. Additional isolated laboratory abnormalities were reported.

In the placebo-controlled studies, when SGOT (AST) and SGPT (ALT) were evaluated, 0.4% (4/978) and 0.4% (11/2677) patients, who received placebo and Prevacid, respectively, had enzyme elevations greater than three times the upper limit of normal range at the final treatment visit. None of these patients who received Prevacid reported jaundice at any time during the study.

In clinical trials using combination therapy with Prevacid plus amoxicillin and clarithromycin, and Prevacid plus amoxicillin, no increased laboratory abnormalities particular to these drug combinations were observed.

For information about laboratory value changes with antibacterial agents (amoxicillin and clarithromycin) indicated in combination with Prevacid or Prevacid SoluTab, refer to the Adverse Reactions section of their prescribing information.

Treatment & Diagnosis

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Medically Reviewed on 8/6/2021
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Professional side effects and drug interactions sections courtesy of the U.S. Food and Drug Administration.