Treatment consisted of a single-dose (Phase A) followed by a once-daily dose for 7 days (Phase B). Doses were prepared as follows: Group 1 = 3 tablets of BIA 2-093 600 mg plus 1 placebo tablet, or 4 placebo tablets; Group 2 = 4 tablets of BIA 2-093 600 mg, or 4 placebo tablets.