Naproxen and esomeprazole magnesium

5 WARNINGS AND PRECAUTIONS Hepatotoxicity: Inform patients of warning signs and symptoms of hepatotoxicity. Discontinue if abnormal liver tests persist or worsen or if clinical signs and symptoms of liver disease develop. ( 5.3 ) Hypertension: Patients taking some antihypertensive medications may have impaired response to these therapies when taking NSAIDs. Monitor blood pressure. ( 5.4 , 7 ) Heart Failure and Edema: Avoid use of naproxen and esomeprazole magnesium delayed-release tablets in patients with severe heart failure unless benefits are expected to outweigh risk of worsening heart failure. ( 5.5 ) Renal Toxicity: Monitor renal function in patients with renal or hepatic impairment, heart failure, dehydration, or hypovolemia. Avoid use of naproxen and esomeprazole magnesium delayed-release tablets in patients with advanced renal disease unless benefits are expected to outweigh risk of worsening renal function. ( 5.6 ) Anaphylactic Reactions: Seek emergency help if an anaphylactic reaction occurs. ( 5.7 ) Exacerbation of Asthma Related to Aspirin Sensitivity: Naproxen and esomeprazole magnesium delayed-release tablets are contraindicated in patients with aspirin-sensitive asthma. Monitor patients with preexisting asthma (without aspirin sensitivity). ( 5.8 ) Serious Skin Reactions: Discontinue naproxen and esomeprazole magnesium delayed-release tablets at first appearance of skin rash or other signs of hypersensitivity. ( 5.9 ) Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS) : Discontinue and evaluate clinically ( 5.10 ) Fetal Toxicity : Limit use of NSAIDs, including naproxen and esomeprazole magnesium delayed-release tablets, between about 20 weeks to 30 weeks in pregnancy due to the risk of oligohydramnios/fetal renal dysfunction. Avoid use of NSAIDs in women at about 30 weeks gestation and later in pregnancy due to the risks of oligohydramnios/fetal renal dysfunction and premature closure of the fetal ductus arteriosus ( 5.11 , 8.1 ) Hematologic Toxicity: Monitor hemoglobin or hematocrit in patients with any signs of symptoms of anemia. ( 5.12 , 7 ) Masking of Inflammation and Fever: Potential for diminished utility of diagnostic signs in detecting infections. ( 5.13 ) Laboratory Monitoring: Obtain CBC and chemistry profile periodically during treatment. Monitor hemoglobin periodically in patients on long-term treatment who have an initial value of 10 g or less. ( 5.14 ) Active Bleeding: Withdraw treatment in patients who experience active and clinically significant bleeding. ( 5.15 ) Concomitant NSAID Use: Do not use naproxen and esomeprazole magnesium delayed-release tablets with other naproxen-containing products or other non-aspirin NSAIDs. ( 5.16 ) Gastric Malignancy: In adults, symptomatic response to esomeprazole does not preclude the presence of gastric malignancy. Consider additional follow-up and diagnostic testing. ( 5.17 ) Acute Tubulointerstitial Nephritis : Discontinue treatment and evaluate patients. ( 5.18 ) Clostridium difficile -Associated Diarrhea: PPI therapy may be associated with increased risk of Clostridium difficile associated diarrhea. ( 5.19 ) 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. ( 5.20 ) Cutaneous and Systemic Lupus Erythematosus: Mostly cutaneous, new onset or exacerbation of existing disease; discontinue naproxen and esomeprazole magnesium delayed-release tablets and refer to specialist for evaluation. ( 5.21 ) Interaction with Clopidogrel: Avoid concomitant use. ( 5.22 , 7 ) Cyanocobalamin (Vitamin B-12) Deficiency: Daily long-term use (e.g., longer than 3 years) may lead to malabsorption or a deficiency of cyanocobalamin. ( 5.23 ) Hypomagnesemia and Mineral Metabolism: Reported rarely with prolonged treatment with PPIs. ( 5.24 ) Interaction with St. John’s Wort or Rifampin: Avoid concomitant use. ( 5.25 , 7 ) Interactions with Diagnostic Investigations for Neuroendocrine Tumors: Increases in intragastric pH may result in hypergastrinemia, enterochromaffin-like cell hyperplasia, and increased Chromogranin A levels which may interfere with diagnostic investigations for neuroendocrine tumors. ( 5.26 ) Interaction with Methotrexate: Concomitant use with PPIs may elevate and/or prolong serum concentrations of methotrexate and/or its metabolite, possibly leading to toxicity. ( 5.27 , 7 ) Fundic Gland Polyps: Risk increases with long-term PPI use, especially beyond one year. Use the shortest duration of therapy. ( 5.28 ) 5.1 Cardiovascular Thrombotic Events Clinical trials of several COX-2 selective and nonselective NSAIDs of up to three years duration have shown an increased risk of serious cardiovascular (CV) thrombotic events, including myocardial infarction (MI), and stroke, which can be fatal. Based on available data, it is unclear that the risk for CV thrombotic events is similar for all NSAIDS. The relative increase in serious CV thrombotic events over baseline conferred by NSAID use appears to be similar in those with and without known CV disease or risk factors for CV disease. However, patients with known CV disease or risk factors had a higher absolute incidence of excess serious CV thrombotic events, due to their increased baseline rate. Some observational studies found that this increased risk of serious CV thrombotic events began as early as the first weeks of treatment. The increase in CV thrombotic risk has been observed most consistently at higher doses. To minimize the potential risk for an adverse CV event in NSAID-treated patients, use the lowest effective dose for the shortest duration possible. Physicians and patients should remain alert for the development of such events, throughout the entire treatment course, even in the absence of previous CV symptoms. Patients should be informed about the symptoms of serious CV events and the steps to take if they occur. There is no consistent evidence that concurrent use of aspirin mitigates the increased risk of serious CV thrombotic events associated with NSAID use. The concurrent use of aspirin and an NSAID, such as naproxen, increases the risk of serious gastrointestinal (GI) events [see Warnings and Precautions ( 5.2 )]. Status Post Coronary Artery Bypass Graft (CABG) Surgery Two large, controlled, clinical trials of a COX-2 selective NSAID for the treatment of pain in the first 10 days to 14 days following CABG surgery found an increased incidence of myocardial infarction and stroke. NSAIDs are contraindicated in the setting of CABG [see Contraindications ( 4 )]. Post-MI Patients Observational studies conducted in the Danish National Registry have demonstrated that patients treated with NSAIDs in the post-MI period were at increased risk of reinfarction, CV-related death, and all-cause mortality beginning in the first week of treatment. In this same cohort, the incidence of death in the first year post-MI was 20 per 100-person years in NSAID-treated patients compared to 12 per 100 person years in non-NSAID exposed patients. Although the absolute rate of death declined somewhat after the first year post-MI, the increased relative risk of death in NSAID users persisted over at least the next four years after follow-up. Avoid the use of naproxen and esomeprazole magnesium delayed-release tablets in patients with a recent MI unless the benefits are expected to outweigh the risk of recurrent CV thrombotic events. If naproxen and esomeprazole magnesium delayed-release tablets are used in patients with a recent MI, monitor patients for signs of cardiac ischemia. 5.2 Gastrointestinal Bleeding, Ulceration, and Perforation NSAIDs, including naproxen, can cause serious gastrointestinal (GI) adverse events including inflammation, bleeding, ulceration, and perforation of the esophagus, stomach, small intestine, or large intestine, which can be fatal. These serious adverse events can occur at any time, with or without warning symptoms, in patients treated with NSAIDs. Only one in five patients who develop a serious upper GI adverse event on NSAID therapy is symptomatic. Upper GI ulcers, gross bleeding, or perforation caused by NSAIDs occurred in approximately 1% of patients treated for 3 months to 6 months, and in about 2% to 4% of patients treated for one year. However, even short-term NSAID therapy is not without risk. Risk Factors for GI Bleeding, Ulceration, and Perforation Patients with a prior history of peptic ulcer disease and/or GI bleeding who used NSAIDs had a greater than 10-fold increased risk for developing a GI bleed compared to patients without these risk factors. Other factors that increase the risk for GI bleeding in patients treated with NSAIDs include longer duration of NSAID therapy; concomitant use of oral corticosteroids, aspirin, anticoagulants, or selective serotonin reuptake inhibitors (SSRIs); smoking; use of alcohol; older age; and poor general health status. Most postmarketing reports of fatal GI events are in elderly or debilitated patients. Additionally, patients with advanced liver disease and/or coagulopathy are at increased risk for GI bleeding. Strategies to Minimize the GI Risks in NSAID-treated patients: Use the lowest effective dosage for the shortest possible duration. Avoid administration of more than one NSAID at a time. Avoid use in patients at higher risk unless benefits are expected to outweigh the increased risk of bleeding. For such as patients, as well as those with active GI bleeding, consider alternate therapies other than NSAIDs. Remain alert for signs and symptoms of GI ulceration and bleeding during NSAID therapy. If a serious GI adverse event is suspected, promptly initiate evaluation and treatment, and discontinue naproxen and esomeprazole magnesium delayed-release tablets until a serious GI adverse event is ruled out. In the setting of concomitant use of low-dose aspirin for cardiac prophylaxis, monitor patients more closely for evidence of GI bleeding [see Drug Interactions ( 7 )]. NSAIDs should be given with care to patients with a history of inflammatory bowel disease (ulcerative colitis, Crohn’s disease) as their condition may be exacerbated. 5.3 Hepatotoxicity Elevations of ALT or AST (three or more times the upper limit of the normal [ULN]) have been reported in approximately 1% of NSAID-treated patients in clinical trials. In addition, rare, and sometimes fatal, cases of severe hepatic injury, including jaundice and fatal fulminant hepatitis, liver necrosis, and hepatic failure have been reported. Elevations of ALT or AST (less than three times ULN) may occur in up to 15% of patients treated with NSAIDs including naproxen. Inform patients of the warning signs and symptoms of hepatotoxicity (e.g., nausea, fatigue, lethargy, diarrhea, pruritus, jaundice, right upper quadrant tenderness, and “flu-like” symptoms). If clinical signs and symptoms consistent with liver disease develop, or if systemic manifestations occur (e.g., eosinophilia, rash, etc.), discontinue naproxen and esomeprazole magnesium delayed-release tablets immediately, and perform a clinical evaluation of the patient. Naproxen and esomeprazole magnesium delayed-release tablets should be avoided in patients with severe hepatic impairment [see Dosage and Administration ( 2 ), Use in Specific Populations ( 8.6 ), and Clinical Pharmacology ( 12.3 )]. 5.4 Hypertension NSAIDs, including naproxen and esomeprazole magnesium delayed-release tablets, can lead to new onset of hypertension or worsening of preexisting hypertension, either of which may contribute to the increased incidence of CV events. Patients taking angiotensin converting enzyme (ACE) inhibitors, thiazides diuretics, or loop diuretics may have impaired response to these therapies when taking NSAIDs [see Drug Interactions ( 7 )]. Monitor blood pressure (BP) during the initiation of NSAID treatment and throughout the course of therapy. 5.5 Heart Failure and Edema The Coxib and traditional NSAID Trialists’ Collaboration meta-analysis of randomized controlled trials demonstrated an approximately two-fold increase in hospitalizations for heart failure in COX-2 selective treated patients and nonselective NSAID-treated patients compared to placebo-treated patients. In a Danish National Registry study of patients with heart failure, NSAID use increased the risk of MI, hospitalization for heart failure, and death. Additionally, fluid retention and edema have been observed in some patients treated with NSAIDs. Use of naproxen may blunt the CV effects of several therapeutic agents used to treat these medical conditions (e.g., diuretics, ACE inhibitors, or angiotensin receptor blockers [ARBs]) [see Drug Interactions ( 7 )]. Avoid the use of naproxen and esomeprazole magnesium delayed-release tablets in patients with severe heart failure unless the benefits are expected to outweigh the risk of worsening heart failure. If naproxen and esomeprazole magnesium delayed-release tablets are used in patients with severe heart failure, monitor patients for signs and symptoms of worsening heart failure. 5.6 Renal Toxicity and Hyperkalemia Renal Toxicity Long-term administration of NSAIDs has resulted in renal papillary necrosis and other renal injury. Renal toxicity has also been seen in patients in whom renal prostaglandins have a compensatory role in the maintenance of renal perfusion. In these patients, administration of an NSAID may cause a dose-dependent reduction in prostaglandin formation and, secondarily, in renal blood flow, which may precipitate overt renal decompensation. Patients at greatest risk of this reaction are those with impaired renal function, dehydration, hypovolemia, heart failure, liver dysfunction, those taking diuretics and ACE-inhibitors or ARBs, and the elderly. Discontinuation of NSAID therapy was usually followed by recovery to the pretreatment state. No information is available from controlled clinical studies regarding the use of naproxen and esomeprazole magnesium delayed-release tablets in patients with advanced renal disease. The renal effects of naproxen and esomeprazole magnesium delayed-release tablets may hasten the progression of renal dysfunction in patients with pre-existing renal disease. Correct volume status in dehydrated or hypovolemic patients prior to initiating naproxen and esomeprazole magnesium delayed-release tablets. Monitor renal function in patients with renal or hepatic impairment, heart failure, dehydration, or hypovolemia during use of naproxen and esomeprazole magnesium delayed-release tablets [see Drug Interactions ( 7 )] . Avoid the use of naproxen and esomeprazole magnesium delayed-release tablets in patients with advanced renal disease unless the benefits are expected to outweigh the risk of worsening renal failure. If naproxen and esomeprazole magnesium delayed-release tablets are used in patients with advanced renal disease, monitor patients for signs of worsening renal function. Hyperkalemia Increases in serum potassium concentration, including hyperkalemia, have been reported with use of NSAIDs, even in some patients without renal impairment. In patients with normal renal function, these effects have been attributed to a hyporeninemic-hypoaldosteronism state. 5.7 Anaphylactic Reactions Naproxen has been associated with anaphylactic reactions in patients with and without known hypersensitivity to naproxen and in patients with aspirin-sensitive asthma [see Contraindications ( 4 ) and Warnings and Precautions ( 5.8 )]. Seek emergency help if an anaphylactic reaction occurs. 5.8 Exacerbation of Asthma Related to Aspirin Sensitivity A subpopulation of patients with asthma may have aspirin-sensitive asthma which may include chronic rhinosinusitis complicated by nasal polyps; severe, potentially fatal bronchospasm; and/or intolerance to aspirin and other NSAIDs. Because cross-reactivity between aspirin and other NSAIDs has been reported in such aspirin-sensitive patients, naproxen and esomeprazole magnesium delayed-release tablets are contraindicated in patients with this form of aspirin sensitivity [see Contraindications ( 4 )] . When naproxen and esomeprazole magnesium delayed-release tablets are used in patients with preexisting asthma (without known aspirin sensitivity), monitor patients for changes in the signs and symptoms of asthma. 5.9 Serious Skin Reactions NSAIDs, including naproxen, can cause serious skin adverse reactions such as exfoliative dermatitis, Stevens-Johnson Syndrome (SJS), and toxic epidermal necrolysis (TEN), which can be fatal. NSAIDs can also cause fixed drug eruption (FDE). FDE may present as a more severe variant known as generalized bullous fixed drug eruption (GBFDE), which can be life-threatening. PPIs can cause severe cutaneous adverse reactions, SJS, TEN, and acute generalized exanthematous pustulosis (AGEP) [see Adverse Reactions ( 6.2 )] .These serious events may occur without warning. Inform patients about the signs and symptoms of serious skin reactions, and to discontinue the use of naproxen and esomeprazole magnesium delayed-release tablets at the first appearance of skin rash or any other sign of hypersensitivity. Naproxen and esomeprazole magnesium delayed-release tablets are contraindicated in patients with previous serious skin reactions to NSAIDs [see Contraindications ( 4 )] . 5.10 Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS) Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS) has been reported in patients taking NSAIDs and PPIs such as those contained in naproxen and esomeprazole magnesium delayed-release tablets. Some of these events have been fatal or life-threatening. DRESS typically, although not exclusively, presents with fever, rash, lymphadenopathy, and/or facial swelling. Other clinical manifestations may include hepatitis, nephritis, hematological abnormalities, myocarditis, or myositis. Sometimes symptoms of DRESS may resemble an acute viral infection. Eosinophilia is often present. Because this disorder is variable in its presentation, other organ systems not noted here may be involved. It is important to note that early manifestations of hypersensitivity, such as fever or lymphadenopathy, may be present even though rash is not evident. If such signs or symptoms are present, discontinue naproxen and esomeprazole magnesium delayed-release tablets and evaluate the patient immediately [see also Warnings and Precautions ( 5.9 )] . 5.11 Fetal Toxicity Premature Closure of Fetal Ductus Arteriosus: Avoid use of NSAIDs, including naproxen and esomeprazole magnesium delayed-release tablets, in pregnant women at about 30 weeks gestation and later. NSAIDs, including naproxen and esomeprazole magnesium delayed-release tablets, increase the risk of premature closure of the fetal ductus arteriosus at approximately this gestational age. Oligohydramnios/Neonatal Renal Impairment: Use of NSAIDs, including naproxen and esomeprazole magnesium delayed-release tablets, at about 20 weeks gestation or later in pregnancy may cause fetal renal dysfunction leading to oligohydramnios and, in some cases, neonatal renal impairment. These adverse outcomes are seen, on average, after days to weeks of treatment, although oligohydramnios has been infrequently reported as soon as 48 hours after NSAID initiation. Oligohydramnios is often, but not always, reversible with treatment discontinuation. Complications of prolonged oligohydramnios may, for example, include limb contractures and delayed lung maturation. In some postmarketing cases of impaired neonatal renal function, invasive procedures such as exchange transfusion or dialysis were required. If NSAID treatment is necessary between about 20 weeks and 30 weeks gestation, limit naproxen and esomeprazole magnesium delayed-release tablets use to the lowest effective dose and shortest duration possible. Consider ultrasound monitoring of amniotic fluid if naproxen and esomeprazole magnesium delayed-release tablets treatment is needed in a pregnant woman. Discontinue naproxen and esomeprazole magnesium delayed-release tablets if oligohydramnios occurs and follow up according to clinical practice [see Use in Specific Populations ( 8.1 )]. 5.12 Hematologic Toxicity Anemia has occurred in NSAID-treated patients. This may be due to occult or gross blood loss, fluid retention, or an incompletely described effect on erythropoiesis. If a patient treated with naproxen and esomeprazole magnesium delayed-release tablets have any signs or symptoms of anemia, monitor hemoglobin or hematocrit. NSAIDs, including naproxen and esomeprazole magnesium delayed-release tablets, may increase the risk of bleeding events. Co-morbid conditions such as coagulation disorders or concomitant use of warfarin and other anticoagulants, antiplatelet agents (e.g., aspirin), and serotonin reuptake inhibitors (SSRIs) and serotonin norepinephrine reuptake inhibitors (SNRIs) may increase the risk. Monitor these patients for signs of bleeding [see Drug Interactions ( 7 )]. 5.13 Masking of Inflammation and Fever The pharmacological activity of naproxen and esomeprazole magnesium delayed-release tablets in reducing inflammation, and possibly fever, may diminish the utility of diagnostic signs in detecting infections. 5.14 Laboratory Monitoring Because serious GI bleeding, hepatotoxicity, and renal injury can occur without warning symptoms or signs, consider monitoring patients on long-term NSAID treatment with a CBC and chemistry profile periodically [see Warnings and Precautions ( 5.2 , 5.3 , 5.6 )]. Patients with initial hemoglobin values of 10 g or less who are to receive long-term therapy should have hemoglobin values determined periodically. 5.15 Active Bleeding When active and clinically significant bleeding from any source occurs in patients receiving naproxen and esomeprazole magnesium delayed-release tablets, the treatment should be withdrawn. 5.16 Concomitant NSAID Use Naproxen and esomeprazole magnesium delayed-release tablets contain naproxen as one of its active ingredients. It should not be used with other naproxen-containing products since they all circulate in the plasma as the naproxen anion. The concomitant use of naproxen and esomeprazole magnesium delayed-release tablets with any dose of a non-aspirin NSAID should be avoided due to the potential for increased risk of adverse reactions. 5.17 Presence of Gastric Malignancy In adults, response to gastric symptoms with naproxen and esomeprazole magnesium delayed-release tablets do not preclude the presence of gastric malignancy. Consider additional gastrointestinal follow-up and diagnostic testing in adult patients who experience gastric symptoms during treatment with naproxen and esomeprazole magnesium delayed-release tablets or have a symptomatic relapse after completing treatment. In older patients, also consider an endoscopy. 5.18 Acute Tubulointerstitial Nephritis Acute 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, 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 naproxen and esomeprazole magnesium delayed-release tablets and evaluate patients with suspected acute TIN [see Contraindications ( 4 )]. 5.19 Clostridium difficile -Associated Diarrhea Published observational studies suggest that proton pump inhibitor (PPI) therapy like naproxen and esomeprazole magnesium delayed-release tablets 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 [see Dosage and Administration ( 2 )]. 5.20 Bone Fracture Several published observational studies suggest that 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 ) , Adverse Reactions ( 6.2 )]. Naproxen and esomeprazole magnesium delayed-release tablets (a combination PPI/NSAID) are approved for use twice a day and does not allow for administration of a lower daily dose of the PPI [see Dosage and Administration ( 2 )]. 5.21 Cutaneous and Systemic Lupus Erythematosus Cutaneous lupus erythematosus (CLE) and systemic lupus erythematosus (SLE) have been reported in patients taking PPIs, including esomeprazole. These events have occurred as both new onset and an exacerbation of existing autoimmune disease. The majority of PPI-induced lupus erythematous 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 inpatients ranging from infants to the elderly. Generally, histological findings were observed without organ involvement. 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 primarily 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 naproxen and esomeprazole magnesium delayed-release tablets, discontinue 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. 5.22 Interaction with Clopidogrel Avoid concomitant use of esomeprazole 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 esomeprazole, that inhibit CYP2C19 activity. Concomitant use of clopidogrel with 40 mg esomeprazole reduces the pharmacological activity of clopidogrel. When using esomeprazole, a component of naproxen and esomeprazole magnesium delayed-release tablets, consider alternative anti-platelet therapy [see Drug Interactions ( 7 ), Clinical Pharmacology ( 12.3 )]. 5.23 Cyanocobalamin (Vitamin B-12) Deficiency Daily 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. 5.24 Hypomagnesemia and Mineral Metabolism Hypomagnesemia, 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 naproxen and esomeprazole magnesium delayed-release tablets 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 naproxen and esomeprazole magnesium delayed-release tablets. 5.25 Concomitant Use of St. John’s Wort or Rifampin with Naproxen and Esomeprazole Magnesium Delayed-Release Tablets Drugs that induce CYP2C19 or CYP3A4 (such as St. John’s Wort or rifampin) can substantially decrease esomeprazole concentrations. Avoid concomitant use of naproxen and esomeprazole magnesium delayed-release tablets with St. John’s Wort or rifampin [see Drug Interactions ( 7 )]. 5.26 Interactions with Diagnostic Investigations for Neuroendocrine Tumors Serum 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 esomeprazole 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 [see Drug Interactions ( 7 ), Clinical Pharmacology ( 12.2 )]. 5.27 Concomitant Use of Naproxen and Esomeprazole Magnesium Delayed-Release Tablets with Methotrexate Literature suggests that concomitant use of PPIs with methotrexate (primarily at high dose; see methotrexate prescribing information) 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 )]. 5.28 Fundic Gland Polyps PPI use is associated with an increased risk of fundic gland polyps that increases with long-term use, especially beyond one year. Most PPI 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.