warnings and cautions
5 WARNINGS AND PRECAUTIONS Gastric Malignancy : In adults, symptomatic response does not preclude the presence of gastric malignancy. Consider additional follow-up and diagnostic testing. ( 5.1 ) Acute Tubulointerstitial Nephritis : discontinue treatment and evaluate patients. ( 5.2 ) Clostridium difficile -Associated Diarrhea : PPI therapy may be associated with increased risk. ( 5.3 ) 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. ( 5.4 ) 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. ( 5.5 ) Cutaneous and Systemic Lupus Erythematosus : Mostly cutaneous; new onset or exacerbation of existing disease; discontinue Omeprazole Delayed-Release Capsules and refer to specialist for evaluation. ( 5.6 ) I n teraction with Clopidogrel : Avoid concomitant use of Omeprazole Delayed-Release Capsules. ( 5.7 , 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. ( 5.8 ) Hypomagnesemia and Mineral Metabolism : Reported rarely with prolonged treatment with PPIs. ( 5.9 ) Interaction with St. John’s Wort or Rifampin : Avoid concomitant use of Omeprazole Delayed-Release Capsules. ( 5.10 , 7 ) Interactions with Diagnostic Investigations for Neuroendocrine Tumors : Increased Chromogranin A (CgA) levels may interfere with diagnostic investigations for neuroendocrine tumors; temporarily stop Omeprazole Delayed-Release Capsules at least 14 days before assessing CgA levels. ( 5.11 , 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 Delayed-Release Capsules. ( 5.12 , 7 ) Fundic Gland Polyps : Risk increases with long-term use, especially beyond one year. Use the shortest duration of therapy. ( 5.13 ) 5.1 Presence of Gastric Malignancy In adults, symptomatic response to therapy with Omeprazole Delayed-Release Capsules 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 PPI. In older patients, also consider an endoscopy. 5.2 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 omeprazole delayed-release capsules and evaluate patients with suspected acute TIN [see Contraindications ( 4 )] . 5.3 Clostridium difficile -Associated Diarrhea Published observational studies suggest that PPI therapy like Omeprazole Delayed-Release Capsules 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 A d verse Reactions ( 6.2 )] . Patients should use the lowest dose and shortest duration of PPI therapy appropriate to the condition being treated. Clostridium difficile -associated diarrhea (CDAD) has been reported with use of nearly all antibacterial agents. For more information specific to antibacterial agents (clarithromycin and amoxicillin) indicated for use in combination with Omeprazole Delayed-Release Capsules, refer to Warnings and Precautions sections of the corresponding prescribing information. 5.4 Bone Fracture Several 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 established treatment guidelines [see D o sage and Administration ( 2.1 ) , A dverse Reactions ( 6.3 )] . 5.5 Severe Cutaneous Adverse Reactions Severe 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 ( 6.3 )] . Discontinue Omeprazole Delayed-Release Capsules at the first signs or symptoms of severe cutaneous adverse reactions or other signs of hypersensitivity and consider further evaluation. 5.6 Cutaneous and Systemic Lupus Erythematosus Cutaneous 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 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 Omeprazole Delayed-Release Capsules, 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. 5.7 Interaction with Clopidogrel Avoid concomitant use of Omeprazole Delayed-Release Capsules 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 inhibit 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 Delayed-Release Capsules, consider alternative anti-platelet therapy [see Drug I nteractions ( 7 ) and C l i n i cal Pharmacology ( 12.3 )] . 5.8 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 in patients treated with Omeprazole Delayed-Release Capsules. 5.9 Hypomagnesemia and Mineral Metabolism Hypomagnesemia, symptomatic and asymptomatic, has been reported in patients treated with PPIs for at least three months, in most cases after a year of therapy. Serious adverse reactions 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. In cases of severe hypocalcemia, both intravenous magnesium and calcium replacement may be required. Consider monitoring magnesium and calcium levels prior to initiation of Omeprazole Delayed-Release Capsules and periodically while on treatment in patients: expected to be on prolonged treatment with Omeprazole Delayed-Release Capsules taking medications such as digoxin or other drugs that may cause hypomagnesemia (e.g., diuretics) or that may cause hypocalcemia with a preexisting risk of hypocalcemia (e.g., hypoparathyroidism) Supplement with magnesium and/or calcium as necessary. 5.10 Interaction with St. John’s Wort or Rifampin Drugs 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 Delayed-Release Capsules with St. John’s Wort or rifampin. 5.11 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. Healthcare providers should temporarily stop Omeprazole Delayed-Release Capsules 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 D rug Interactions ( 7 )] . 5.12 Interaction with Methotrexate Literature 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 )] . 5.13 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.