The main objectives of the present study are to investigate the basic pharmacokinetics of BI 671800, its major metabolite CD6384, and 14C-radioactivity, including mass balance, excretion pathways and metabolism following a single oral dose of 400 mg [14C]BI 671800 HEA to healthy male volunteers. Secondary objectives are to evaluate the safety and tolerability following a single oral dose of 400 mg [14C]BI 671800 HEA to healthy male volunteers.