Vonoprazan

Table 9 and Table 10 include drugs with clinically important drug interactions and interaction with diagnostics when administered concomitantly with VOQUEZNA and instructions for preventing or managing them. These recommendations are based on either drug interaction trials or predicted interactions due to the expected magnitude of interaction and potential for serious adverse reactions or loss of efficacy [see Clinical Pharmacology (12.3) ] . Consult the labeling of concomitantly used drugs to obtain further information about interactions with vonoprazan.

Table 9: Drug Interactions Affecting Drugs Co-Administered with VOQUEZNA and Interactions with Diagnostics Drugs Dependent on Gastric pH for Absorption Antiretrovirals Clinical Effect Vonoprazan reduces intragastric acidity [see Clinical Pharmacology (12.2) ], which may alter the absorption of antiretroviral drugs, leading to changes in the safety and/or effectiveness. Prevention or Management Rilpivirine-containing products Concomitant use with VOQUEZNA is contraindicated . Atazanavir Avoid concomitant use with VOQUEZNA.

Nelfinavir Other antiretrovirals See the prescribing information of other antiretroviral drugs dependent on gastric pH for absorption prior to concomitant use with VOQUEZNA. Other Drugs (e.g., iron salts, erlotinib, dasatinib, nilotinib, mycophenolate mofetil, ketoconazole/itraconazole) Clinical Effect Vonoprazan reduces intragastric acidity [see Clinical Pharmacology (12.2) ] , which may decrease the absorption of drugs reducing their effectiveness. Prevention or Management See the prescribing information for other drugs dependent on gastric pH for absorption.

Combination Therapy with Clarithromycin and/or Amoxicillin Clinical Effect Concomitant administration of clarithromycin with other drugs can lead to serious adverse reactions, including potentially fatal arrhythmias, and is contraindicated. Amoxicillin also has drug interactions. Prevention or Management See Contraindications and Warnings and Precautions in the prescribing information for clarithromycin. See Drug Interactions in the prescribing information for amoxicillin. Certain CYP3A Substrates Where Minimal Concentration Changes May Lead to Serious Toxicities Clinical Effect Vonoprazan is a weak CYP3A inhibitor [see Clinical Pharmacology (12.3) ] .

Vonoprazan may increase exposure of CYP3A4 substrates, which may increase the risk of adverse reactions related to these substrates. Prevention or Management Frequently monitor concentrations and/or adverse reactions related to the substrate drugs when used with VOQUEZNA. Dosage reduction of substrate drugs may be needed. See prescribing information for the relevant substrate drugs. CYP2C19 Substrates (e.g., clopidogrel, citalopram, cilostazol) Clinical Effect Vonoprazan is a CYP2C19 inhibitor [see Clinical Pharmacology (12.3) ] . Vonoprazan may reduce plasma concentrations of the active metabolite of clopidogrel and may cause reduction in platelet inhibition.

Vonoprazan may increase exposure of CYP2C19 substrate drugs (e.g., citalopram, cilostazol). Prevention or Management Clopidogrel Carefully monitor the efficacy of clopidogrel and consider alternative anti-platelet therapy. Citalopram and Cilostazol Carefully monitor patients for adverse reactions associated with citalopram and cilostazol. See the prescribing information for dosage adjustments. Chromogranin Test for Neuroendocrine Tumors Clinical Effect Vonoprazan reduces intragastric acidity [see Clinical Pharmacology (12.2) ] , which increases CgA levels and may cause false positive results in diagnostic investigations for neuroendocrine tumors .

Prevention or Management Assess CgA levels at least 4 weeks after stopping VOQUEZNA treatment and repeat the test if initial CgA levels are high. If serial tests are performed (e.g., for monitoring), use the same commercial laboratory for testing, as reference ranges between tests may vary. Interaction with Secretin Stimulation Test Clinical Effect Hyper-response in gastrin secretion in response to secretin stimulation test, falsely suggesting gastrinoma. Prevention or Management Temporarily stop VOQUEZNA at least 4 weeks before assessing to allow gastrin levels to return to normal [see Clinical Pharmacology (12.2) ] .

Table 10: Drug Interactions Affecting VOQUEZNA When Co-Administered with Other Drugs Strong or Moderate CYP3A4 Inducers Clinical Effect Vonoprazan is a CYP3A substrate. Strong or moderate CYP3A inducers decrease vonoprazan exposure [see Clinical Pharmacology (12.3) ], which may reduce the effectiveness of VOQUEZNA. Prevention or Management Avoid concomitant use with VOQUEZNA. See full prescribing information for a list of clinically important drug interactions. ( 7 )

8.1 Pregnancy Pregnancy Exposure Registry There is a pregnancy exposure registry that monitors pregnancy outcomes in women exposed to VOQUEZNA during pregnancy. Healthcare providers are encouraged to register patients by calling 1-866-609-1612 or visiting https://voqueznapregnancyregistry.com/ . Risk Summary There are no adequate and well-controlled studies of vonoprazan in pregnant women. Available data from pharmacovigilance reports with vonoprazan-containing products used in pregnant women are not sufficient to evaluate for a drug-associated risk for major birth defects, miscarriage, or other adverse maternal or fetal outcomes.

In pregnant rats, no adverse effects were noted after oral administration of vonoprazan during organogenesis at approximately 27-times the maximum recommended human dose (MRHD), based on AUC exposure comparisons. In a pre- and postnatal development (PPND) study, pups from dams orally administered vonoprazan during organogenesis and through lactation exhibited liver discoloration, which, in follow-up mechanistic animal studies, was associated with necrosis, fibrosis, and hemorrhage at a dose approximately 22-times the MRHD, based on AUC comparisons that were likely attributable to exposure during lactation [see Use in Specific Populations (8.2) ] .

These effects were not observed at the next lower dose in this study, which was approximately equal to the MRHD, based on AUC comparison; however, they were seen at clinically relevant exposures in dose range-finding studies in rats (see Data) . The background risks of major birth defects and miscarriage for the indicated population are unknown. All pregnancies have a background risk of birth defects, loss, or other adverse outcomes. In the United States 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.

Data Animal Data Pregnant rats were orally administered vonoprazan at doses of 30, 100, or 300 mg/kg/day (7-, 27-, 130-times the MRHD based on AUC comparison at the same doses from unmated female rats from separate studies) during the period of organogenesis from gestation day (GD) 6 to 17. During maternal dosing, one high-dose female died and decreased body weight and food consumption occurred at the middle and highest doses. No embryo-fetal lethality was observed but decreased fetal body weight was observed in the highest dose group. Fetal abnormalities were limited to the 300 mg/kg/day and included ventricular septal defect and mal-positioned subclavian artery in…