Myfortic Drug Interactions

Observed interactions resulting in a concomitant use not recommended: Azathioprine: It is recommended that Myfortic should not be co-administered with azathioprine because such co-administration has not been studied (see Precautions).
Live vaccines: Live vaccines should not be given to patients with an impaired immune response. The antibody response to other vaccines may be diminished (see Precautions).
Observed interactions to be considered: Aciclovir: Higher plasma concentrations of both MPAG (mycophenolic acid glucuronide) and aciclovir may occur in the presence of renal impairment. Therefore, the potential exists for these two drugs to compete for tubular secretion, resulting in a further increase in the concentration of both MPAG and aciclovir. In this situation patients should be carefully monitored.
Gastroprotective agents: Antacids with magnesium and aluminium hydroxides: The absorption of mycophenolate sodium was decreased when administered with antacids. Co-administration of Myfortic and antacids containing magnesium and aluminium hydroxide results in a 37% decrease in MPA systemic exposure and a 25% decrease in MPA maximal concentration. Caution should be used when co-administering antacids (containing magnesium and aluminium hydroxide) with Myfortic.
Proton pump inhibitors: In healthy volunteers, co-administration of 1000 mg MMF and 40 mg pantoprazole twice daily led to a 27% decrease in MPA AUC and to a 57% decrease in MPA C_max. However, in the same study, no changes in the pharmacokinetics of MPA were observed following co-administration of Myfortic and pantoprazole.
Ganciclovir: MPA and MPAG pharmacokinetics are unaffected by the addition of ganciclovir. The clearance of ganciclovir is unchanged in the setting of therapeutic MPA exposure. However, in patients with renal impairment in which Myfortic and ganciclovir are coadministered the dose recommendations for ganciclovir should be observed and patients monitored carefully.
Tacrolimus: In a calcineurin cross-over study in stable renal transplant patients, steady state Myfortic pharmacokinetics were measured during both Neoral and tacrolimus treatments. Mean MPA AUC was 19% higher and C_max about 20% lower. Conversely mean MPAG AUC and C_max were about 30% lower on tacrolimus treatment compared to Neoral treatment.
Ciclosporin A: When studied in stable renal transplant patients, ciclosporin A pharmacokinetics were unaffected by steady state dosing of Myfortic.
Anticipated interactions to be considered: Cholestyramine and drugs that interfere with enterohepatic circulation: Due to its capacity to block the enteric circulation of drugs, cholestyramine may decrease the systemic exposure of MPA. Caution should be used when co-administering cholestyramine or drugs that interfere with enterohepatic circulation due to the potential to reduce the efficacy of Myfortic.
Oral contraceptives: Oral contraceptives undergo oxidative metabolism while Myfortic is metabolized by glucuronidation. A clinically significant effect of oral contraceptives on Myfortic pharmacokinetics is not anticipated. However, as the long term effect of Myfortic dosing on the pharmacokinetics of oral contraceptives is not known, it is possible that the efficacy of oral contraceptives may be adversely affected (see Use in Pregnancy & Lactation).