Drug interactions with carbamazepine: An ever expanding list?

In a study that applied a nonlinear mixed effect model to evaluate factors affecting steady-state serum carbamazepine concentrations in elderly nursing home residents, co-administration of iron supplements was reported to reduce serum carbamazepine concentrations by approximately one third. Although these findings suggest that iron ions reduce the oral bioavailability of carbamazepine, the influence of confounders cannot be excluded. Further studies are required to confirm this interaction.