The median time to Cmax (tmax) for ACT 178882 is prolonged from 3.5 to 5.0 h by diltiazem whereas its apparent terminal half-life (t?) is unaffected by diltiazem, 22.9 and 24.2 h for treatments A and B, respectively. Using treatment A as reference, the geometric mean ratio (90% CI) is 1.62 (1.36 to 1.94) for Cmax and 2.02 (1.75 to 2.34) for AUC∞, indicating a significant interaction between ACT 178882 and diltiazem[2].