Tamolarizine (also known as NC-1100), an organic Ca2+ channel blocker, was studied in clinical trials phase II in patients with neurological disorders. However, these studies were discontinued. In addition, experiments on rodents have shown that tamolarizine treatment protected the hippocampus from ischemic brain damage and ameliorated place learning impairment. Tamolarizine was also able to reverse the multidrug-resistance phenotype in human leukemia K562 cells through direct interaction with P-glycoprotein.