Drs. Carnahan and Perry comment that the medication labeling—"A," "B," and "C," denoting "low," "medium," and "high" doses—would alert investigators at day 7 to treatment assignment because all patients randomly assigned to ziprasidone received 80 mg b.i.d. (the "high" dose) on days 3 to 7 and all patients randomly assigned to olanzapine received 10 mg/day (the "medium" dose). The "A," "B," and "C" labeling was, in fact, employed only during the flexible-dose weeks of the study (weeks 2 to 6). During days 1 to 2 and days 3 to 7, when fixed doses were administered, the medication cards did not contain this labeling. During both the fixed titration and flexible-dose phases of the study, the patients in the two treatment arms received identical quantities of medication of identical appearance; in the olanzapine group, placebo capsules were employed to simulate twice-a-day dosing. For example, a subject who was assigned to olanzapine at 10 mg/day would have received the same number of identical-appearing capsules twice a day as a subject who was assigned to ziprasidone at 80 mg b.i.d. with this "double-dummy" design. Thus, there was no potential for unblinding in the drug-administration protocol.