Vonoprazan

Gastric Malignancy : Symptomatic response to treatment 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 ) Clostridioides difficile -Associated Diarrhea (CDAD) : May be associated with an increased risk; use the shortest duration of treatment appropriate to the condition. ( 5.3 ) Bone Fracture, including Osteoporosis-related Fracture : Use the shortest duration of treatment appropriate to the condition. ( 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 ) Vitamin B12 (Cobalamin) Deficiency : Long-term use may lead to malabsorption or deficiency; consider further workup if clinical symptoms are present. ( 5.6 ) Hypomagnesemia and Mineral Metabolism : Hypomagnesemia may lead to hypocalcemia and/or hypokalemia. Consider monitoring magnesium and calcium levels in at-risk patients, or if there is concomitant use of digoxin or other drugs that cause hypomagnesemia. ( 5.7 ) Interactions with Investigations for Neuroendocrine Tumors : Increased chromogranin A (CgA) levels may interfere with diagnostic investigations; temporarily stop VOQUEZNA at least 4 weeks before assessing CgA levels. ( 5.8 , 7 ) Fundic Gland Polyps : Risk increases with long-term use; use the shortest duration of treatment appropriate to the condition. ( 5.9 )

Presence of Gastric Malignancy In adults, symptomatic response to therapy with VOQUEZNA does not preclude the presence of gastric malignancy. Consider additional follow-up and diagnostic testing in patients who have a suboptimal response or an early symptomatic relapse after completing treatment with VOQUEZNA. In older patients, also consider endoscopy.

Acute Tubulointerstitial Nephritis Acute tubulointerstitial nephritis (TIN) has been reported with VOQUEZNA [see Adverse Reactions (6.1) ] . If suspected, discontinue VOQUEZNA and evaluate patients with suspected acute TIN.

Clostridioides difficile -Associated Diarrhea Published observational studies suggest that proton pump inhibitors (PPIs) may be associated with an increased risk of Clostridioides difficile -associated diarrhea (CDAD), especially in hospitalized patients. VOQUEZNA, another drug that blocks the proton pump to inhibit gastric acid production, may also increase the risk of CDAD. Consider CDAD in patients with diarrhea that does not improve [see Adverse Reactions (6.2) ] . Use the shortest duration of VOQUEZNA appropriate to the condition being treated. 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 VOQUEZNA, refer to the Warnings and Precautions section of the corresponding prescribing information.

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 therapy (a year or longer). Bone fracture, including osteoporosis-related fracture, has also been reported with vonoprazan. Use the shortest duration of VOQUEZNA appropriate to the condition being treated [see Dosage and Administration (2.1) ]. Patients at risk for osteoporosis-related fractures should be managed according to the established treatment guidelines .

Severe Cutaneous Adverse Reactions Severe cutaneous adverse reactions, including Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) have been reported with VOQUEZNA [see Adverse Reactions (6.2) ] . Discontinue VOQUEZNA at the first signs or symptoms of severe cutaneous adverse reactions or other signs of hypersensitivity and consider further evaluation.

Vitamin B12 (Cobalamin) Deficiency Long-term use of acid-suppressing drugs can lead to malabsorption of Vitamin B12 caused by hypo- or achlorhydria. Vitamin B12 deficiency has been reported postmarketing with vonoprazan [see Adverse Reactions (6.2) ]. If clinical symptoms consistent with Vitamin B12 deficiency are observed in patients treated with VOQUEZNA consider further workup.

Hypomagnesemia and Mineral Metabolism Hypomagnesemia has been reported postmarketing with vonoprazan [see Adverse Reactions (6.2) ] . Hypomagnesemia may lead to hypocalcemia and/or hypokalemia and may exacerbate underlying hypocalcemia in at-risk patients. Consider monitoring magnesium levels prior to initiation of VOQUEZNA and periodically in patients expected to be on prolonged treatment, in patients taking drugs that may have increased toxicity in the presence of hypomagnesemia (e.g., digoxin), or drugs that may cause hypomagnesemia (e.g., diuretics). Treatment of hypomagnesemia may require magnesium replacement and discontinuation of VOQUEZNA. Consider monitoring magnesium and calcium levels prior to initiation of VOQUEZNA 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 VOQUEZNA.

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. Temporarily discontinue VOQUEZNA treatment at least 4 weeks 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) and Clinical Pharmacology (12.2) ] .

Fundic Gland Polyps Use of VOQUEZNA is associated with a risk of fundic gland polyps that increases with long-term use, especially beyond one year. Fundic gland polyps have been reported with vonoprazan in clinical trials and postmarketing use with PPIs. Most patients who developed fundic gland polyps were asymptomatic and fundic gland polyps were identified incidentally on endoscopy. Use the shortest duration of VOQUEZNA appropriate to the condition being treated [see Dosage and Administration (2.1) ] .