Mycophenolate Antacids

ANTACIDS MYCOPHENOLATE 1 plasma concentrations of mycophenolate (may be 30%) 1 absorption Do not co-administer simultaneously -separate by at least 4 hours... 

Most of the interactions with mycophenolate mofetil and enteric-coated MPA are due to reductions in intestinal absorption. Aluminum-, magnesium-, or calcium-containing antacids decrease the peak level and overall exposure of MPA from either of the preparations.11 If a patient requires liquid antacids, they should be administered at least 4 hours before... 

Drugs that may affect mycophenolate include acyclovir, antacids, azathioprine, cholestyramine, ganciclovir, iron, probenecid, and salicylates. 

Drug Interactions Acyclovir Antacids with magnesium and aluminum hydroxides Cholestyramine Drugs that alter gastrointestinal flora may interact with mycophenolate mofetil by disrupting enterohepatic recirculation Probenecid... 

The coadministration of mycophenolate mofetil with antacids results in decreased absorption. The plasma MPA concentration is significantly reduced by cholestyramine due to binding of the cholestyramine to MPAG in the intestine and interfering with the enterohepatic recirculation of the drug. The bioavailability of mycophenolate mofetil is higher when administered with tacrolimus as opposed to cyclosporine. The bioavailability of MPA is reduced by antibiotics including fluoroquinolones and metronidazole. 

An aluminium/magnesium hydroxide antacid reduced the absorption of mycophenolate in one study, but the ciinicai reievance of this is uncertain. 

Bullingham R, Shah J, Goldblum R, Schiff M. Effects of food and antacid on the pharmacokinetics of single doses of mycophenolate mofetil in rheumatoid arthritis patients, BrJ Clin Pharmacol (1996) 41, 513-16. 

A study in 5 healthy subjects given a single 1-g dose of myeophenolate alone or with polycarbophil calcium 2.4 g found that the AUC and peak serum levels of mycophenolic acid were redueed by about 51% and 69%, respectively. The authors suggest that this interaction was probably the result of reduced absorption due to chelate-complex formation between mycophenolate and the calcium ions, which they demonstrated in an in vitro study. It was concluded that mycophenolate and polycarbophil calcium should not be taken at the same time. A suitable interval was not specified, but a separation of 2 hours has been suggested with antacids , (p.l067), which interact by a similar mechanism. Further study is needed. 

Drag-drag interactions Pantoprazole Proton pump inhibitors suppress acid production and thus increase stomach pH, while mycophenolate mofetil is cleaved in the acidic milieu of the stomach. Of 36 patients with autoimmune diseases taking stable mycophenolate mofetil maintenance therapy, 23 took pantoprazole, and 13 patients received no proton pump inhibitors or antacids [98 j. Pantoprazole reduced the AUC of mycophenolate mofetil by 37% and the Cmax by 60%. 

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