H2-receptor antagonist influences dasatinib pharmacokinetics in a patient with Philadelphia-positive acute lymphoblastic leukemia.

We recently reported in this journal that administration of acid suppressant such as an H2-receptor antagonist (H2RA) and a proton pump inhibitor can decrease the absorption of dasatinib from the gastrointestinal tract, thereby resulting in a significant decrease in its plasma concentration. Here, we report a patient treated with dasatinib and H2RA famotidine for whom the total area under the total plasma concentration-time curve (AUC(0-12)) of dasatinib dramatically increased after cessation of famotidine from 505.7 to 1,816.3 ng·h/mL. This is the first report to confirm the drug interaction between dasatinib and H2RA by using sequential pharmacokinetic profiling.