Drug Interaction Report

GENERALLY AVOID: Coadministration with antacids, H2-receptor antagonists, proton pump inhibitors, or other agents with acid neutralizing or reducing effects may decrease the oral bioavailability and plasma concentrations of ampicillin from bacampicillin. The exact mechanism of interaction is unknown but may be related to degradation of the prodrug when gastric pH is increased.

MANAGEMENT: The possibility of a reduced or subtherapeutic response to bacampicillin should be considered during coadministration with antacids, H2-receptor antagonists, proton pump inhibitors, or other agents that can increase gastric pH. Preferably, these agents should be avoided during therapy with bacampicillin, or an alternative antibiotic be prescribed if these medications cannot be discontinued. Patients treated with antacids (or oral medications that contain antacids such as didanosine buffered tablets or pediatric oral solution) may minimize the effects of the interaction with bacampicillin by separating the times of administration by at least 2 hours.

ADJUST DOSING INTERVAL: Products containing aluminum, calcium, magnesium and other polyvalent cations such as antacids or vitamin with mineral supplements are likely to interfere with the gastrointestinal absorption of oral bisphosphonates. For example, the bioavailability of tiludronate has been shown to decrease 80% during simultaneous administration with calcium, and 60% when aluminum- or magnesium-containing antacids were administered one hour before tiludronate.

MANAGEMENT: Antacids or other oral medications containing aluminum, calcium, magnesium and other polyvalent cations should be administered at least 30 minutes after the bisphosphonate dose.

ADJUST DOSING INTERVAL: Administration with food may increase the absorption of calcium. However, foods high in oxalic acid (spinach or rhubarb), or phytic acid (bran and whole grains) may decrease calcium absorption.

MANAGEMENT: Calcium may be administered with food to increase absorption. Consider withholding calcium administration for at least 2 hours before or after consuming foods high in oxalic acid or phytic acid.

ADJUST DOSING INTERVAL: Food significantly decreases the bioavailability of risedronate, possibly to negligible levels.

MANAGEMENT: Risedronate should be administered with 180 to 240 mL (6 to 8 ounces) of plain water, at least 30 minutes before the first food, beverage, or medication of the day. Patients should remain upright for at least 30 minutes following administration of risedronate.