- Concomitant Medications: Growth factors that support platelet or white cell number or function administered within the past 3 days, currently receiving investigational drugs, or who have received an investigational drug within the last 7 days, currently receiving other anti-cancer agents, currently taking phenobarbital, phenytoin, carbamazepine, oxcarbazepine (Trileptal), rifampin, voriconazole, itraconazole, ketoconazole or other systemically-administered azole antifungal drugs, aprepitant (Emend), or St. John's Wort, requiring antihypertensive agents at the time of enrollment, receiving medications known to inhibit platelet function or known to selectively inhibit cyclooxygenase activity, with the exception of acetaminophen.