- Oral or injectable cytochrome P450 3A4 (CYP3A4) or breast cancer resistance protein (BRCP) substrates with a narrow therapeutic index (CYP3A4 substrates include, but are not limited to, alfenatil, cyclosporine, dihydroergotamine, ergotamine, fentanyl, pimozide, quinidine, sirolimus, tacrolimus, and theophylline; BCRP substrates include, but are not limited to, topotecan) The Investigator should consult with the medical monitor if necessary.