Drug Interaction Report

Iron and zinc may reduce each other's absorption when they are coadministered orally. The mechanism of interaction is unknown. In clinical studies, concurrent supplementation with iron and zinc was associated with reduced efficacy in improving the growth and iron and zinc status of malnourished infants compared to supplementation with either one alone. It is not known whether the interaction occurs in adults. In any case, the clinical significance is probably minimal in healthy individuals. However, monitoring for reduced therapeutic response may be advisable in malnourished patients. Limited data suggest that the magnitude of the interaction may be lessened by separating the times of administration of each by 12 hours.

ADJUST DOSING INTERVAL: Concomitant use of some oral medications may reduce the bioavailability of orally administered iron, and vice versa.

Food taken in conjunction with oral iron supplements may reduce the bioavailability of the iron. However, in many patients intolerable gastrointestinal side effects occur necessitating administration with food.

MANAGEMENT: Ideally, iron products should be taken on an empty stomach (i.e., at least 1 hour before or 2 hours after meals), but if this is not possible, administer with meals and monitor the patient more closely for a subtherapeutic effect. Some studies suggest administration of iron with ascorbic acid may enhance bioavailability. In addition, administration of oral iron products and some oral medications should be separated whenever the bioavailability of either agent may be decreased. Consult the product labeling for specific separation times and monitor clinical responses as appropriate.