Drug Interaction Report

ADJUST DOSING INTERVAL: Because sodium zirconium cyclosilicate can transiently increase gastric pH, it may affect the absorption of coadministered medications that exhibit pH-dependent solubility. Altered efficacy or safety of these medications may occur when they are administered too close to the dosing of sodium zirconium cyclosilicate. According to the product labeling, 39 drugs were tested to determine potential interactions with sodium zirconium cyclosilicate. Drugs that did not show an in vitro interaction with sodium zirconium cyclosilicate were allopurinol, apixaban, aspirin, captopril, cyclosporine, digoxin, ethyl estradiol, lisinopril, magnesium, metformin, phenytoin, prednisone, propranolol, quinapril, spironolactone, and ticagrelor. Of the 23 drugs that showed an in vitro interaction, nine were subsequently tested in healthy volunteers. Losartan, glipizide, and levothyroxine did not demonstrate an in vivo interaction with sodium zirconium cyclosilicate. However, an increase in systemic exposure was observed for weak acids such as furosemide and atorvastatin when coadministered with sodium zirconium cyclosilicate, while a decrease in systemic exposure was observed for weak bases such as dabigatran.

MANAGEMENT: In general, concomitant oral medications should be administered at least 2 hours before or 2 hours after sodium zirconium cyclosilicate. Separation of dosing times is not needed if it has been determined that the concomitant medication does not exhibit pH-dependent solubility.

ADJUST DOSING INTERVAL: Consumption of food has led to a 27% decrease in the bioavailability of orally administered tacrolimus.

MANAGEMENT: Tacrolimus should be administered at least one hour before or two hours after meals.

GENERALLY AVOID: Grapefruit juice has been reported to increase tacrolimus trough concentrations. Data are limited, but inhibition of the CYP450 enzyme system appears to be involved.

MANAGEMENT: The clinician may want to recommend that the patient avoid ingesting large amounts of grapefruit juice while taking tacrolimus.

ADJUST DOSING INTERVAL: Because sodium zirconium cyclosilicate can transiently increase gastric pH, it may affect the absorption of coadministered medications that exhibit pH-dependent solubility. Altered efficacy or safety of these medications may occur when they are administered too close to the dosing of sodium zirconium cyclosilicate. According to the product labeling, 39 drugs were tested to determine potential interactions with sodium zirconium cyclosilicate. Drugs that did not show an in vitro interaction with sodium zirconium cyclosilicate were allopurinol, apixaban, aspirin, captopril, cyclosporine, digoxin, ethyl estradiol, lisinopril, magnesium, metformin, phenytoin, prednisone, propranolol, quinapril, spironolactone, and ticagrelor. Of the 23 drugs that showed an in vitro interaction, nine were subsequently tested in healthy volunteers. Losartan, glipizide, and levothyroxine did not demonstrate an in vivo interaction with sodium zirconium cyclosilicate. However, an increase in systemic exposure was observed for weak acids such as furosemide and atorvastatin when coadministered with sodium zirconium cyclosilicate, while a decrease in systemic exposure was observed for weak bases such as dabigatran.

MANAGEMENT: In general, concomitant oral medications should be administered at least 2 hours before or 2 hours after sodium zirconium cyclosilicate. Separation of dosing times is not needed if it has been determined that the concomitant medication does not exhibit pH-dependent solubility.