- Current use or anticipated need for food or drugs that are known potent CYP3A4 inhibitors, including their administration within 7-days prior to the first PD 0332991dose (i.e. grapefruit juice, verapamil, ketoconazole, miconazole, itraconazole, posaconazole, erythromycin, clarithromycin, telithromycin, indinavir, saquinavir, ritonavir, nelfinavir, lopinavir, nefazodone, diltiazem, atazanavir, amprenavir,and fosamprenavir)