A phase I study to determine the effect of tamoxifen on the pharmacokinetics of a single 250 mg oral dose of gefitinib (IRESSA) in healthy male volunteers.

Objectives: To determine the effect of tamoxifen on the pharmacokinetics of a single 250 mg oral dose of gefitinib (IRESSA) in healthy volunteers.

Methods: An open-label, single-center, phase I study in healthy male volunteers. Each volunteer received a single 250 mg oral dose of gefitinib on day 1.