In clinical trials using combination therapy with lansoprazole plus amoxicillin and clarithromycin, and lansoprazole 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 lansoprazole, amoxicillin, or clarithromycin.
Triple Therapy: Lansoprazole/amoxicillin/clarithromycin
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: Lansoprazole/amoxicillin
The most frequently reported adverse reactions for patients who received lansoprazole 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 lansoprazole three times daily plus amoxicillin three times daily dual therapy than with lansoprazole alone. For information about adverse reactions with antibacterial agents (amoxicillin and clarithromycin) indicated in combination with lansoprazole, refer to the Adverse Reactions section of their prescribing information.
The following changes in laboratory parameters in patients who received lansoprazole 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 lansoprazole, 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 lansoprazole reported jaundice at any time during the study.
In clinical trials using combination therapy with lansoprazole plus amoxicillin and clarithromycin, and lansoprazole 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 lansoprazole, refer to the Adverse Reactions section of their prescribing information.
Tables 2 and 3 include drugs with clinically important drug interactions and interaction with diagnostics when administered concomitantly with lansoprazole 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 Coadministered with Lansoprazole 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.|
|Intervention:||Rilpivirine-containing products: Concomitant use with lansoprazole is contraindicated [see Contraindications ( 4)] . See prescribing information. Atazanavir: See prescribing information for atazanavir for dosing information. Nelfinavir: Avoid concomitant use with lansoprazole. 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 [see Warnings and Precautions ( 5.8)] .|
|Intervention:||A temporary withdrawal of lansoprazole 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 [see Clinical Pharmacology ( 12.3)] .|
|Intervention:||Individual patients may require additional titration of their theophylline dosage when lansoprazole 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.|
|Intervention:||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 lansoprazole and MMF. Use lansoprazole with caution in transplant patients receiving and 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.|
|Intervention:||• 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 [see Warnings and Precautions ( 5.7), Clinical Pharmacology ( 12.2)] .|
|Intervention:||Temporarily stop lansoprazole 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 lansoprazole treatment at least 28 days before assessing to allow gastrin levels to return to baseline [see Clinical Pharmacology ( 12.2)].|
|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 Lansoprazole When Co-Administered with Other Drugs
|CYP2C19 OR CYP3A4 Inducers|
|Clinical Impact:||Decreased exposure of lansoprazole when used concomitantly with strong inducers [see Clinical Pharmacology ( 12.3)] .|
|Intervention:||St John’s Wort, rifampin: Avoid concomitant use with lansoprazole. Ritonavir-containing products: See prescribing information.|
|CYP2C19 or CYP3A4 Inhibitors|
|Clinical Impact:||Increased exposure of lansoprazole is expected when used concomitantly with strong inhibitors [see Clinical Pharmacology ( 12.3)] .|
|Intervention:||Voriconazole: See prescribing information.|
|Clinical Impact:||Decreased and delayed absorption of lansoprazole [see Clinical Pharmacology ( 12.3)] .|
|Intervention:||Take lansoprazole at least 30 minutes prior to sucralfate [see Dosage and Administration ( 2.4)] .|
8 USE IN SPECIFIC POPULATIONS
Available data from published observational studies overall do not indicate an association of adverse pregnancy outcomes with lansoprazole treatment (see Data).
In animal reproduction studies, oral administration of lansoprazole to rats during organogenesis through lactation at 6.4 times the maximum recommended human dose produced reductions in the offspring in femur weight, femur length, crown-rump length and growth plate thickness (males only) on postnatal Day 21 (see Data). These effects were associated with reduction in body weight gain. Advise pregnant women of the potential risk to the fetus.
The estimated background risk of major birth defects and miscarriage for the indicated populations are unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the US general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2 to 4% and 15 to 20%, respectively.
If lansoprazole is administered with clarithromycin, the pregnancy information for clarithromycin also applies to the combination regimen. Refer to the prescribing information for clarithromycin for more information on use in pregnancy.
Available data from published observational studies failed to demonstrate an association of adverse pregnancy-related outcomes and lansoprazole use. Methodological limitations of these observational studies cannot definitely establish or exclude any drug-associated risk during pregnancy. In a prospective study by the European Network of Teratology Information Services, outcomes from a group of 62 pregnant women administered median daily doses of 30 mg of lansoprazole were compared to a control group of 868 pregnant women who did not take any PPIs. There was no difference in the rate of major malformations between women exposed to PPIs and the control group, corresponding to a Relative Risk (RR)=1.04, [95% Confidence Interval (CI) 0.25 to 4.21]. In a population-based retrospective cohort study covering all live births in Denmark from 1996 to 2008, there was no significant increase in major birth defects during analysis of first trimester exposure to lansoprazole in 794 live births. A meta-analysis that compared 1,530 pregnant women exposed to PPIs in at least the first trimester with 133,410 unexposed pregnant women showed no significant increases in risk for congenital malformations or spontaneous abortion with exposure to PPIs (for major malformations Odds Ratio (OR)=1.12, [95% CI 0.86 to 1.45] and for spontaneous abortions OR=1.29, [95% CI 0.84 to 1.97]).
No adverse effects on embryo-fetal development occurred in studies performed in pregnant rats at oral lansoprazole doses up to 150 mg/kg/day (40 times the recommended human dose [30 mg/day] based on body surface area) administered during organogenesis and pregnant rabbits at oral lansoprazole doses up to 30 mg/kg/day (16 times the recommended human dose based on body surface area) administered during organogenesis.
A pre- and postnatal developmental toxicity study in rats with additional endpoints to evaluate bone development was performed with lansoprazole at oral doses of 10 to 100 mg/kg/day (0.7 to 6.4 times the maximum recommended human lansoprazole dose of 30 mg based on AUC [area under the plasma concentration-time curve]) administered during organogenesis through lactation. Maternal effects observed at 100 mg/kg/day (6.4 times the maximum recommended human lansoprazole dose of 30 mg based on AUC) included increased gestation period, decreased body weight gain during gestation, and decreased food consumption. The number of stillbirths was increased at this dose, which may have been secondary to maternal toxicity. Body weight of pups was reduced at 100 mg/kg/day starting on postnatal Day 11. Femur weight, femur length, and crown-rump length were reduced at 100 mg/kg/day on postnatal Day 21. Femur weight was still decreased in the 100 mg/kg/day group at age 17 to 18 weeks. Growth plate thickness was decreased in the 100 mg/kg/day males on postnatal Day 21, and was increased in the 30 and 100 mg/kg/day males at age 17 to 18 weeks. The effects on bone parameters were associated with reduction in body weight gain.
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