Omeprazole/bicarbonate
(Omeprazole And Sodium Bicarbonate)Omeprazole/Bicarbonate Prescribing Information
- short-term treatment of active duodenal ulcer. Most patients heal within four weeks. Some patients may require an additional four weeks of therapy.
- short-term treatment (4 to 8 weeks) of active benign gastric ulcer.
- treatment of heartburn and other symptoms associated with GERD for up to 4 weeks.
- short-term treatment (4 to 8 weeks) of EE due to acid-mediated GERD which has been diagnosed by endoscopy in adults.
- The efficacy of omeprazole and sodium bicarbonate used for longer than 8 weeks in patients with EE has not been established. If a patient does not respond to 8 weeks of treatment, an additional 4 weeks of treatment may be given. If there is recurrence of EE or GERD symptoms (e.g., heartburn), additional 4 to 8-week courses of omeprazole and sodium bicarbonate may be considered.
- maintenance of healing of EE due to acid-mediated GERD. Controlled studies do not extend beyond 12 months.
| Indication | Recommended Adult Dosage |
|---|---|
| Omeprazole and sodium bicarbonate capsules | |
| Active Duodenal Ulcer | 20 mg once daily for 4 weeks; some patients may require an additional 4 weeks |
| Active Benign Gastric Ulcer | 40 mg once daily for 4 to 8 weeks |
| Treatment of Symptomatic GERD | 20 mg once daily for up to 4 weeks |
| Treatment of EE due to Acid-Mediated GERD | 20 mg once daily for 4 to 8 weeksan additional 4 weeks of treatment may be given if no response; if recurrence, additional 4 to 8-week courses may be considered. |
| Maintenance of Healing of EE due to Acid-Mediated GERD | 20 mg once dailystudied for 12 months. |
8.6 Hepatic ImpairmentIn patients with hepatic impairment (Child-Pugh Class A, B, or C) exposure to omeprazole substantially increased compared to healthy subjects. Avoid use of omeprazole and sodium bicarbonate in patients with hepatic impairment for maintenance of healing of erosive esophagitis
8.7 Asian PopulationIn studies of healthy subjects, Asians had approximately a four-fold higher exposure than Caucasians. Avoid use of omeprazole and sodium bicarbonate in Asian patients for maintenance of healing of erosive esophagitis
Omeprazole and sodium bicarbonate is contraindicated in patients with known hypersensitivity to substituted benzimidazoles or to any component of the formulation. Hypersensitivity reactions may include anaphylaxis, anaphylactic shock, angioedema, bronchospasm, acute tubulointerstitial nephritis, and urticaria
5.2 Acute Tubulointerstitial NephritisAcute tubulointerstitial nephritis (TIN) has been observed in patients taking PPIs and may occur at any point during PPI therapy. Patients may present with varying signs and symptoms from symptomatic hypersensitivity reactions to non-specific symptoms of decreased renal function (e.g., malaise, nausea and anorexia). In reported case series, some patients were diagnosed on biopsy and in the absence of extra-renal manifestations (e.g., fever, rash or arthralgia). Discontinue omeprazole and sodium bicarbonate and evaluate patients with suspected acute TIN
6.2 Postmarketing ExperienceThe following adverse reactions have been identified during post-approval use of omeprazole and sodium bicarbonate. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.
Metabolic alkalosis, seizures, and tetany.
Proton pump inhibitors (PPIs), including omeprazole and sodium bicarbonate, are contraindicated in patients receiving rilpivirine containing products
7 DRUG INTERACTIONSConsult the labeling of concomitantly used drugs to obtain further information about interactions with PPIs.
Antiretrovirals | |
Clinical Impact: | The effect of PPIs on antiretroviral drugs is variable. The clinical importance and the mechanisms behind these interactions are not always known.
|
Intervention: | Rilpivirine-containing products: Concomitant use with omeprazole and sodium bicarbonate is contraindicated[see Contraindications (4)]. Atazanavir: Avoid concomitant use with omeprazole and sodium bicarbonate. See prescribing information for atazanavir for dosing information.Nelfinavir: Avoid concomitant use with omeprazole and sodium bicarbonate. See prescribing information for nelfinavir.Saquinavir: See the prescribing information for saquinavir for monitoring of potential saquinavir-related toxicities.Other antiretrovirals: See prescribing information for specific antiretroviral drugs. |
Warfarin | |
Clinical Impact: | Increased INR and prothrombin time in patients receiving PPIs, including omeprazole, and warfarin concomitantly. Increases in INR and prothrombin time may lead to abnormal bleeding and even death. |
Intervention: | Monitor INR and prothrombin time and adjust the dose of warfarin, if needed, to maintain target INR range. |
Methotrexate | |
Clinical Impact: | Concomitant use of omeprazole 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 (5.12)]. |
Intervention: | A temporary withdrawal of omeprazole and sodium bicarbonate may be considered in some patients receiving high-dose methotrexate. |
CYP2C19 Substrates (e.g., clopidogrel, citalopram, cilostazol, phenytoin, diazepam) | |
Clopidogrel | |
Clinical Impact: | Concomitant use of omeprazole 80 mg results in reduced plasma concentrations of the active metabolite of clopidogrel and a reduction in platelet inhibition [see Clinical Pharmacology (12.3)]. There are no adequate combination studies of a lower dose of omeprazole or a higher dose of clopidogrel in comparison with the approved dose of clopidogrel . |
Intervention: | Avoid concomitant use with omeprazole and sodium bicarbonate. Consider use of alternative anti-platelet therapy [see Warnings and Precautions (5.7)]. |
Citalopram | |
Clinical Impact: | Increased exposure of citalopram leading to an increased risk of QT prolongation [see Clinical Pharmacology (12.3)]. |
Intervention: | Limit the dose of citalopram to a maximum of 20 mg per day. See prescribing information for citalopram. |
Cilostazol | |
Clinical Impact: | Increased exposure of one of the active metabolites of cilostazol (3,4-dihydrocilostazol) [see Clinical Pharmacology (12.3)]. |
Intervention: | Reduce the dose of cilostazol to 50 mg twice daily. See prescribing information for cilostazol. |
Phenytoin | |
Clinical Impact: | Potential for increased exposure of phenytoin. |
Intervention: | Monitor phenytoin serum concentrations. Dose adjustment may be needed to maintain therapeutic drug concentrations. See prescribing information for phenytoin. |
Diazepam | |
Clinical Impact: | Increased exposure of diazepam [see Clinical Pharmacology (12.3)]. |
Intervention: | Monitor patients for increased sedation and reduce the dose of diazepam as needed. |
Digoxin | |
| Clinical Impact: | Potential for increased exposure of digoxin [see Clinical Pharmacology (12.3)]. |
| Intervention: | Monitor digoxin concentrations. Dose adjustment may be needed to maintain therapeutic drug concentrations. See digoxin prescribing information. |
Drugs Dependent on Gastric pH for Absorption (e.g., iron salts, erlotinib, dasatinib, nilotinib, mycophenolate mofetil, ketoconazole/itraconazole) | |
Clinical Impact: | Omeprazole can reduce the absorption of other drugs due to its effect on reducing intragastric acidity. |
Intervention: | Mycophenolate mofetil (MMF): Co-administration of omeprazole 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 omeprazole and sodium bicarbonate and MMF. Use omeprazole and sodium bicarbonate with caution in transplant patients receiving MMF [see Clinical Pharmacology (12.3)]. See the prescribing information for other drugs dependent on gastric pH for absorption. |
Tacrolimus | |
Clinical Impact: | Potential for increased exposure of tacrolimus, especially in transplant patients who are intermediate or poor metabolizers of CYP2C19 . |
Intervention: | Monitor tacrolimus whole blood concentrations. Dose adjustment may be needed to maintain therapeutic drug concentrations. See prescribing information for tacrolimus. |
Interactions with Investigations of Neuroendocrine Tumors | |
Clinical Impact: | Serum chromogranin A (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 (5.11)and Clinical Pharmacology (12.2)]. |
Intervention: | Temporarily stop PRILOSEC 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 omeprazole and sodium bicarbonate treatment at least 14 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. |
Other | |
Clinical Impact: | There have been clinical reports of interactions with other drugs metabolized via the cytochrome P450 system (e.g., cyclosporine, disulfiram). |
Intervention: | Monitor patients to determine if it is necessary to adjust the dosage of these other drugs when taken concomitantly with omeprazole and sodium bicarbonate. |
CYP2C19 or CYP3A4 Inducers | |
Clinical Impact: | Decreased exposure of omeprazole when used concomitantly with strong inducers [see Clinical Pharmacology (12.3)]. |
Intervention: | St. John's wort, rifampin : Avoid concomitant use with omeprazole and sodium bicarbonate[see Warnings and Precautions (5.10)]. Ritonavir-containing products : See prescribing information for specific drugs. |
CYP2C19 or CYP3A4 Inhibitors | |
Clinical Impact: | Increased exposure of omeprazole [see Clinical Pharmacology (12.3)]. |
Intervention: | Voriconazole : Dosage adjustment of omeprazole and sodium bicarbonate is not required. |
See full prescribing information for a list of clinically important drug interactions.
- Gastric Malignancy:In adults, symptomatic response does not preclude the presence of gastric malignancy. Consider additional follow-up and diagnostic testing. ()
5.1 Presence of Gastric MalignancyIn adults, symptomatic response to therapy with omeprazole and sodium bicarbonate does not preclude the presence of gastric malignancy. Consider additional follow-up and diagnostic testing in adult patients who have a suboptimal response or an early symptomatic relapse after completing treatment with a proton pump inhibitor (PPI). In older patients, also consider an endoscopy.
- Acute Tubulointerstitial Nephritis:Discontinue treatment and evaluate patients. ()
5.2 Acute Tubulointerstitial NephritisAcute tubulointerstitial nephritis (TIN) has been observed in patients taking PPIs and may occur at any point during PPI therapy. Patients may present with varying signs and symptoms from symptomatic hypersensitivity reactions to non-specific symptoms of decreased renal function (e.g., malaise, nausea and anorexia). In reported case series, some patients were diagnosed on biopsy and in the absence of extra-renal manifestations (e.g., fever, rash or arthralgia). Discontinue omeprazole and sodium bicarbonate and evaluate patients with suspected acute TIN
[see Contraindications (4)]. - Sodium Bicarbonate Buffer Content:Take sodium content into consideration in patients on a sodium-restricted diet. Avoid in patients with Bartter's syndrome, hypokalemia, hypocalcemia, and problems with acid-base balance. ()
5.3 Sodium Bicarbonate Buffer ContentEach 20 mg and 40 mg omeprazole and sodium bicarbonate capsule contains 1,100 mg (13 mEq) of sodium bicarbonate. The total content of sodium in each capsule is 304 mg.
Chronic administration of bicarbonate with calcium or milk can cause milk-alkali syndrome. Chronic use of sodium bicarbonate may lead to systemic alkalosis, and increased sodium intake can produce edema and weight gain.
The sodium content of omeprazole and sodium bicarbonate products should be taken into consideration when administering to patients on a sodium-restricted diet or those at risk for developing congestive heart failure.
Avoid omeprazole and sodium bicarbonate in patients with Bartter's syndrome, hypokalemia, hypocalcemia, and problems with acid-base balance.
- : PPI therapy may be associated with increased risk. (Clostridium difficile-Associated Diarrhea)
5.4Clostridium difficile-Associated DiarrheaPublished observational studies suggest that PPI therapy like omeprazole and sodium bicarbonate may be associated with an increased risk of
Clostridium difficile-associated diarrhea, especially in hospitalized patients. This diagnosis should be considered for diarrhea that does not improve[see Adverse Reactions (6.2)].Patients should use the lowest dose and shortest duration of PPI therapy appropriate to the condition being treated.
- Bone Fracture:Long-term and multiple daily dose PPI therapy may be associated with an increased risk for osteoporosis-related fractures of the hip, wrist, or spine. ()
5.5 Bone FractureSeveral published observational studies suggest that proton pump inhibitor (PPI) therapy may be associated with an increased risk for osteoporosis-related fractures of the hip, wrist, or spine. The risk of fracture was increased in patients who received high-dose, defined as multiple daily doses, and long-term PPI therapy (a year or longer). Patients should use the lowest dose and shortest duration of PPI therapy appropriate to the condition being treated. Patients at risk for osteoporosis-related fractures should be managed according to the established treatment guidelines
[see Dosage and Administration (2.2)and Adverse Reactions (6.2)]. - Severe Cutaneous Adverse Reactions: Discontinue at the first signs or symptoms of severe cutaneous adverse reactions or other signs of hypersensitivity and consider further evaluation. ()
5.6 Severe Cutaneous Adverse ReactionsSevere cutaneous adverse reactions, including Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN), drug reaction with eosinophilia and systemic symptoms (DRESS), and acute generalized exanthematous pustulosis (AGEP) have been reported in association with the use of PPIs
[see Adverse Reactions (6.2)].Discontinue omeprazole and sodium bicarbonate at the first signs or symptoms of severe cutaneous adverse reactions or other signs of hypersensitivity and consider further evaluation. - Cutaneous and Systemic Lupus Erythematosus:Mostly cutaneous; new onset or exacerbation of existing disease; discontinue omeprazole and sodium bicarbonate and refer to specialist for evaluation. ()
5.7 Cutaneous and Systemic Lupus ErythematosusCutaneous lupus erythematosus (CLE) and systemic lupus erythematosus (SLE) have been reported in patients taking PPIs, including omeprazole. These events have occurred as both new onset and an exacerbation of existing autoimmune disease. The majority of PPI-induced lupus erythematosus cases were CLE.
The most common form of CLE reported in patients treated with PPIs was subacute CLE (SCLE) and occurred within weeks to years after continuous drug therapy in patients ranging from infants to the elderly. Generally, histological findings were observed without organ involvement.
Systemic lupus erythematosus (SLE) is less commonly reported than CLE in patients receiving PPIs. PPI associated SLE is usually milder than non-drug induced SLE. Onset of SLE typically occurred within days to years after initiating treatment in patients ranging from young adults to the elderly. The majority of patients presented with rash; however, arthralgia and cytopenia were also reported.
Avoid administration of PPIs for longer than medically indicated. If signs or symptoms consistent with CLE or SLE are noted in patients receiving omeprazole and sodium bicarbonate, discontinue the drug and refer the patient to the appropriate specialist for evaluation. Most patients improve with discontinuation of the PPI alone in 4 to 12 weeks. Serological testing (e.g., ANA) may be positive and elevated serological test results may take longer to resolve than clinical manifestations.
- Interaction with Clopidogrel:Avoid concomitant use of omeprazole and sodium bicarbonate. ()
5.8 Interaction with ClopidogrelAvoid concomitant use of omeprazole and sodium bicarbonate with clopidogrel. Clopidogrel is a prodrug. Inhibition of platelet aggregation by clopidogrel is entirely due to an active metabolite. The metabolism of clopidogrel to its active metabolite can be impaired by use with concomitant medications, such as omeprazole, that interfere with CYP2C19 activity. Concomitant use of clopidogrel with 80 mg omeprazole reduces the pharmacological activity of clopidogrel, even when administered 12 hours apart. When using omeprazole and sodium bicarbonate, consider alternative antiplatelet therapy
[see Drug Interactions (7)and Clinical Pharmacology (12.3)]. - Cyanocobalamin (Vitamin B-12) Deficiency:Daily long-term use (e.g., longer than 3 years) may lead to malabsorption or a deficiency of cyanocobalamin. ()
5.9 Cyanocobalamin (Vitamin B-12) DeficiencyDaily treatment with any acid-suppressing medications over a long period of time (e.g., longer than 3 years) may lead to malabsorption of cyanocobalamin (vitamin B-12) caused by hypo- or achlorhydria. Rare reports of cyanocobalamin deficiency occurring with acid-suppressing therapy have been reported in the literature. This diagnosis should be considered if clinical symptoms consistent with cyanocobalamin deficiency are observed in patients treated with omeprazole and sodium bicarbonate.
- Hypomagnesemia and Mineral Metabolism:Reported rarely with prolonged treatment with PPIs. ()
5.10 Hypomagnesemia and Mineral MetabolismHypomagnesemia, symptomatic and asymptomatic, has been reported rarely in patients treated with PPIs for at least three months, in most cases after a year of therapy. Serious adverse events include tetany, arrhythmias, and seizures. Hypomagnesemia may lead to hypocalcemia and/or hypokalemia and may exacerbate underlying hypocalcemia in at-risk patients. In most patients, treatment of hypomagnesemia required magnesium replacement and discontinuation of the PPI.
For patients expected to be on prolonged treatment or who take PPIs with medications such as digoxin or drugs that may cause hypomagnesemia (e.g., diuretics), health care professionals may consider monitoring magnesium levels prior to initiation of PPI treatment and periodically
[see Adverse Reactions (6.2)].Consider monitoring magnesium and calcium levels prior to initiation of omeprazole and sodium bicarbonate and periodically while on treatment in patients with a preexisting risk of hypocalcemia (e.g., hypoparathyroidism). Supplement with magnesium and/or calcium as necessary. If hypocalcemia is refractory to treatment, consider discontinuing the PPI.
- Interaction with St. John's wort or Rifampin:Avoid concomitant use of omeprazole and sodium bicarbonate. (,
5.11 Interaction with St. John's wort or RifampinDrugs which induce CYP2C19 or CYP3A4 (such as St. John's wort or rifampin) can substantially decrease omeprazole concentrations
[see Drug Interactions (7)].Avoid concomitant use of omeprazole and sodium bicarbonate with St. John's wort or rifampin.)7 DRUG INTERACTIONSTables 6and7include drugs with clinically important drug interactions and interaction with diagnostics when administered concomitantly with omeprazole and instructions for preventing or managing them.Consult the labeling of concomitantly used drugs to obtain further information about interactions with PPIs.
Table 6: Clinically Relevant Interactions Affecting Drugs Co-Administered with Omeprazole and Interaction with Diagnostics AntiretroviralsClinical 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 omeprazole may reduce antiviral effect and promote the development of drug resistance[see Clinical Pharmacology (12.3)].
- Increased exposure of other antiretroviral drugs (e.g., saquinavir) when used concomitantly with omeprazole may increase toxicity[see Clinical Pharmacology (12.3)].
- There are other antiretroviral drugs which do not result in clinically relevant interactions with omeprazole.
Intervention:Rilpivirine-containing products:Concomitant use with omeprazole and sodium bicarbonate is contraindicated[see Contraindications (4)].Atazanavir:Avoid concomitant use with omeprazole and sodium bicarbonate. See prescribing information for atazanavir for dosing information.Nelfinavir:Avoid concomitant use with omeprazole and sodium bicarbonate. See prescribing information for nelfinavir.Saquinavir:See the prescribing information for saquinavir for monitoring of potential saquinavir-related toxicities.Other antiretrovirals:See prescribing information for specific antiretroviral drugs.WarfarinClinical Impact:Increased INR and prothrombin time in patients receiving PPIs, including omeprazole, and warfarin concomitantly. Increases in INR and prothrombin time may lead to abnormal bleeding and even death. Intervention:Monitor INR and prothrombin time and adjust the dose of warfarin, if needed, to maintain target INR range. MethotrexateClinical Impact:Concomitant use of omeprazole 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 (5.12)].Intervention:A temporary withdrawal of omeprazole and sodium bicarbonate may be considered in some patients receiving high-dose methotrexate. CYP2C19 Substrates (e.g., clopidogrel, citalopram, cilostazol, phenytoin, diazepam)ClopidogrelClinical Impact:Concomitant use of omeprazole 80 mg results in reduced plasma concentrations of the active metabolite of clopidogrel and a reduction in platelet inhibition [see Clinical Pharmacology (12.3)].
There are no adequate combination studies of a lower dose of omeprazole or a higher dose of clopidogrel in comparison with the approved dose of clopidogrel.Intervention:Avoid concomitant use with omeprazole and sodium bicarbonate. Consider use of alternative anti-platelet therapy [see Warnings and Precautions (5.7)].CitalopramClinical Impact:Increased exposure of citalopram leading to an increased risk of QT prolongation [see Clinical Pharmacology (12.3)].Intervention:Limit the dose of citalopram to a maximum of 20 mg per day. See prescribing information for citalopram. CilostazolClinical Impact:Increased exposure of one of the active metabolites of cilostazol (3,4-dihydrocilostazol) [see Clinical Pharmacology (12.3)].Intervention:Reduce the dose of cilostazol to 50 mg twice daily. See prescribing information for cilostazol. PhenytoinClinical Impact:Potential for increased exposure of phenytoin. Intervention:Monitor phenytoin serum concentrations. Dose adjustment may be needed to maintain therapeutic drug concentrations. See prescribing information for phenytoin. DiazepamClinical Impact:Increased exposure of diazepam [see Clinical Pharmacology (12.3)].Intervention:Monitor patients for increased sedation and reduce the dose of diazepam as needed. DigoxinClinical Impact: Potential for increased exposure of digoxin [see Clinical Pharmacology (12.3)].Intervention: Monitor digoxin concentrations. Dose adjustment may be needed to maintain therapeutic drug concentrations. See digoxin prescribing information. Drugs Dependent on Gastric pH for Absorption (e.g., iron salts, erlotinib, dasatinib, nilotinib, mycophenolate mofetil, ketoconazole/itraconazole)Clinical Impact:Omeprazole can reduce the absorption of other drugs due to its effect on reducing intragastric acidity. Intervention:Mycophenolate mofetil (MMF): Co-administration of omeprazole 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 omeprazole and sodium bicarbonate and MMF. Use omeprazole and sodium bicarbonate with caution in transplant patients receiving MMF [see Clinical Pharmacology (12.3)].
See the prescribing information for other drugs dependent on gastric pH for absorption.TacrolimusClinical Impact:Potential for increased exposure of tacrolimus, especially in transplant patients who are intermediate or poor metabolizers of CYP2C19 .Intervention:Monitor tacrolimus whole blood concentrations. Dose adjustment may be needed to maintain therapeutic drug concentrations. See prescribing information for tacrolimus. Interactions with Investigations of Neuroendocrine TumorsClinical Impact:Serum chromogranin A (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 (5.11)and Clinical Pharmacology (12.2)].Intervention:Temporarily stop PRILOSEC 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 TestClinical Impact:Hyper-response in gastrin secretion in response to secretin stimulation test, falsely suggesting gastrinoma. Intervention:Temporarily stop omeprazole and sodium bicarbonate treatment at least 14 days before assessing to allow gastrin levels to return to baseline [see Clinical Pharmacology (12.2)].False Positive Urine Tests for THCClinical 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. OtherClinical Impact:There have been clinical reports of interactions with other drugs metabolized via the cytochrome P450 system (e.g., cyclosporine, disulfiram). Intervention:Monitor patients to determine if it is necessary to adjust the dosage of these other drugs when taken concomitantly with omeprazole and sodium bicarbonate. Table 7: Clinically Relevant Interactions Affecting Omeprazole When Co-Administered with Other Drugs CYP2C19 or CYP3A4 InducersClinical Impact:Decreased exposure of omeprazole when used concomitantly with strong inducers [see Clinical Pharmacology (12.3)].Intervention:St. John's wort, rifampin: Avoid concomitant use with omeprazole and sodium bicarbonate[see Warnings and Precautions (5.10)].Ritonavir-containing products: See prescribing information for specific drugs.CYP2C19 or CYP3A4 InhibitorsClinical Impact:Increased exposure of omeprazole [see Clinical Pharmacology (12.3)].Intervention:Voriconazole: Dosage adjustment of omeprazole and sodium bicarbonate is not required.See full prescribing information for a list of clinically important drug interactions.
- Decreased exposure of some antiretroviral drugs (e.g., rilpivirine, atazanavir and nelfinavir) when used concomitantly with omeprazole may reduce antiviral effect and promote the development of drug resistance
- Interactions with Diagnostic Investigations for Neuroendocrine Tumors:Increased Chromogranin A (CgA) levels may interfere with diagnostic investigations for neuroendocrine tumors; temporarily stop omeprazole and sodium bicarbonate at least 14 days before assessing CgA levels. ()
5.12 Interactions with Investigations for Neuroendocrine TumorsSerum chromogranin A (CgA) levels increase secondary to drug-induced decreases in gastric acidity. The increased CgA level may cause false positive results in diagnostic investigations for neuroendocrine tumors. Providers should temporarily stop omeprazole and sodium bicarbonate treatment for 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
[see Drug Interactions (7)]. - Interaction with Methotrexate:Concomitant use with PPIs may elevate and/or prolong serum concentrations of methotrexate and/or its metabolite, possibly leading to toxicity. With high dose methotrexate administration, consider a temporary withdrawal of omeprazole and sodium bicarbonate. (,
5.13 Interaction with MethotrexateLiterature suggests that concomitant use of PPIs with methotrexate (primarily at high dose) may elevate and prolong serum levels of methotrexate and/or its metabolite, possibly leading to methotrexate toxicities. In high-dose methotrexate administration, a temporary withdrawal of the PPI may be considered in some patients
[see Drug Interactions (7)].)7 DRUG INTERACTIONSTables 6and7include drugs with clinically important drug interactions and interaction with diagnostics when administered concomitantly with omeprazole and instructions for preventing or managing them.Consult the labeling of concomitantly used drugs to obtain further information about interactions with PPIs.
Table 6: Clinically Relevant Interactions Affecting Drugs Co-Administered with Omeprazole and Interaction with Diagnostics AntiretroviralsClinical 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 omeprazole may reduce antiviral effect and promote the development of drug resistance[see Clinical Pharmacology (12.3)].
- Increased exposure of other antiretroviral drugs (e.g., saquinavir) when used concomitantly with omeprazole may increase toxicity[see Clinical Pharmacology (12.3)].
- There are other antiretroviral drugs which do not result in clinically relevant interactions with omeprazole.
Intervention:Rilpivirine-containing products:Concomitant use with omeprazole and sodium bicarbonate is contraindicated[see Contraindications (4)].Atazanavir:Avoid concomitant use with omeprazole and sodium bicarbonate. See prescribing information for atazanavir for dosing information.Nelfinavir:Avoid concomitant use with omeprazole and sodium bicarbonate. See prescribing information for nelfinavir.Saquinavir:See the prescribing information for saquinavir for monitoring of potential saquinavir-related toxicities.Other antiretrovirals:See prescribing information for specific antiretroviral drugs.WarfarinClinical Impact:Increased INR and prothrombin time in patients receiving PPIs, including omeprazole, and warfarin concomitantly. Increases in INR and prothrombin time may lead to abnormal bleeding and even death. Intervention:Monitor INR and prothrombin time and adjust the dose of warfarin, if needed, to maintain target INR range. MethotrexateClinical Impact:Concomitant use of omeprazole 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 (5.12)].Intervention:A temporary withdrawal of omeprazole and sodium bicarbonate may be considered in some patients receiving high-dose methotrexate. CYP2C19 Substrates (e.g., clopidogrel, citalopram, cilostazol, phenytoin, diazepam)ClopidogrelClinical Impact:Concomitant use of omeprazole 80 mg results in reduced plasma concentrations of the active metabolite of clopidogrel and a reduction in platelet inhibition [see Clinical Pharmacology (12.3)].
There are no adequate combination studies of a lower dose of omeprazole or a higher dose of clopidogrel in comparison with the approved dose of clopidogrel.Intervention:Avoid concomitant use with omeprazole and sodium bicarbonate. Consider use of alternative anti-platelet therapy [see Warnings and Precautions (5.7)].CitalopramClinical Impact:Increased exposure of citalopram leading to an increased risk of QT prolongation [see Clinical Pharmacology (12.3)].Intervention:Limit the dose of citalopram to a maximum of 20 mg per day. See prescribing information for citalopram. CilostazolClinical Impact:Increased exposure of one of the active metabolites of cilostazol (3,4-dihydrocilostazol) [see Clinical Pharmacology (12.3)].Intervention:Reduce the dose of cilostazol to 50 mg twice daily. See prescribing information for cilostazol. PhenytoinClinical Impact:Potential for increased exposure of phenytoin. Intervention:Monitor phenytoin serum concentrations. Dose adjustment may be needed to maintain therapeutic drug concentrations. See prescribing information for phenytoin. DiazepamClinical Impact:Increased exposure of diazepam [see Clinical Pharmacology (12.3)].Intervention:Monitor patients for increased sedation and reduce the dose of diazepam as needed. DigoxinClinical Impact: Potential for increased exposure of digoxin [see Clinical Pharmacology (12.3)].Intervention: Monitor digoxin concentrations. Dose adjustment may be needed to maintain therapeutic drug concentrations. See digoxin prescribing information. Drugs Dependent on Gastric pH for Absorption (e.g., iron salts, erlotinib, dasatinib, nilotinib, mycophenolate mofetil, ketoconazole/itraconazole)Clinical Impact:Omeprazole can reduce the absorption of other drugs due to its effect on reducing intragastric acidity. Intervention:Mycophenolate mofetil (MMF): Co-administration of omeprazole 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 omeprazole and sodium bicarbonate and MMF. Use omeprazole and sodium bicarbonate with caution in transplant patients receiving MMF [see Clinical Pharmacology (12.3)].
See the prescribing information for other drugs dependent on gastric pH for absorption.TacrolimusClinical Impact:Potential for increased exposure of tacrolimus, especially in transplant patients who are intermediate or poor metabolizers of CYP2C19 .Intervention:Monitor tacrolimus whole blood concentrations. Dose adjustment may be needed to maintain therapeutic drug concentrations. See prescribing information for tacrolimus. Interactions with Investigations of Neuroendocrine TumorsClinical Impact:Serum chromogranin A (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 (5.11)and Clinical Pharmacology (12.2)].Intervention:Temporarily stop PRILOSEC 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 TestClinical Impact:Hyper-response in gastrin secretion in response to secretin stimulation test, falsely suggesting gastrinoma. Intervention:Temporarily stop omeprazole and sodium bicarbonate treatment at least 14 days before assessing to allow gastrin levels to return to baseline [see Clinical Pharmacology (12.2)].False Positive Urine Tests for THCClinical 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. OtherClinical Impact:There have been clinical reports of interactions with other drugs metabolized via the cytochrome P450 system (e.g., cyclosporine, disulfiram). Intervention:Monitor patients to determine if it is necessary to adjust the dosage of these other drugs when taken concomitantly with omeprazole and sodium bicarbonate. Table 7: Clinically Relevant Interactions Affecting Omeprazole When Co-Administered with Other Drugs CYP2C19 or CYP3A4 InducersClinical Impact:Decreased exposure of omeprazole when used concomitantly with strong inducers [see Clinical Pharmacology (12.3)].Intervention:St. John's wort, rifampin: Avoid concomitant use with omeprazole and sodium bicarbonate[see Warnings and Precautions (5.10)].Ritonavir-containing products: See prescribing information for specific drugs.CYP2C19 or CYP3A4 InhibitorsClinical Impact:Increased exposure of omeprazole [see Clinical Pharmacology (12.3)].Intervention:Voriconazole: Dosage adjustment of omeprazole and sodium bicarbonate is not required.See full prescribing information for a list of clinically important drug interactions.
- Decreased exposure of some antiretroviral drugs (e.g., rilpivirine, atazanavir and nelfinavir) when used concomitantly with omeprazole may reduce antiviral effect and promote the development of drug resistance
- Fundic Gland Polyps: Risk increases with long-term use, especially beyond one year. Use the shortest duration of therapy. ()
5.14 Fundic Gland PolypsPPI use is associated with an increased risk of fundic gland polyps that increases with long-term use, especially beyond one year. Most PPIs users who developed fundic gland polyps were asymptomatic and fundic gland polyps were identified incidentally on endoscopy. Use the shortest duration of PPI therapy appropriate to the condition being treated.