Drug Interactions between amoxicillin / clarithromycin / vonoprazan and sirolimus

GENERALLY AVOID: Coadministration with potent inhibitors of CYP450 3A4 and/or P-glycoprotein (P-gp) may significantly increase the plasma concentrations of sirolimus following oral administration. Sirolimus is a substrate of both CYP450 3A4 isoenzyme and P-gp efflux transporter, thus their inhibition in the intestine can enhance the absorption of sirolimus. In 23 healthy volunteers, administration of a single 5 mg dose of sirolimus with the potent dual CYP450 3A4/P-gp inhibitor ketoconazole (200 mg/day orally for 10 days) increased mean sirolimus peak plasma concentration (Cmax) and systemic exposure (AUC) by approximately 4- and 11-fold, respectively. Likewise, posaconazole (400 mg oral suspension twice a day for 16 days) increased mean Cmax and AUC of a single 2 mg dose of sirolimus by nearly 7- and 9-fold, respectively, while voriconazole (400 mg orally every 12 hours for 1 day, then 200 mg every 12 hours for 8 days) increased the same values by 7- and 11-fold, respectively. Another dual inhibitor, boceprevir (800 mg three times a day for 11 days), increased the Cmax and AUC of a single 2 mg dose of sirolimus by 10- and 17-fold, respectively. When sirolimus 2 mg once a day was coadministered with the moderate dual inhibitor erythromycin (ethylsuccinate salt 800 mg every 8 hours) in 24 study subjects, sirolimus Cmax and AUC increased by more than 4-fold each, while erythromycin Cmax and AUC also increased by more than 1.5-fold each.

MANAGEMENT: Concomitant use of sirolimus with potent CYP450 3A4 and/or P-gp inhibitors should generally be avoided. The manufacturers of posaconazole and voriconazole consider coadministration with sirolimus to be contraindicated. Some authorities recommend avoiding concomitant use of sirolimus during and for 2 weeks after treatment with itraconazole.

MONITOR: Coadministration with drugs that are inhibitors of CYP450 3A4 may increase the blood concentrations of the macrolide immunosuppressants sirolimus and tacrolimus, both of which are metabolized by the isoenzyme.

MANAGEMENT: The possibility of prolonged and/or increased pharmacologic effects of macrolide immunosuppressant therapy should be considered, including adverse effects such as fever, infection, diarrhea, hypokalemia, anemia, thrombocytopenia, leukopenia, and hyperlipidemia. Dosage adjustments as well as clinical and laboratory monitoring may be appropriate whenever a CYP450 3A4 inhibitor is added to or withdrawn from therapy.

Although some in vitro data indicate synergism between macrolide antibiotics and penicillins, other in vitro data indicate antagonism. When these drugs are given together, neither has predictable therapeutic efficacy. Data are available for erythromycin, although theoretically this interaction could occur with any macrolide. Except for monitoring of the effectiveness of antibiotic therapy, no special precautions appear to be necessary.