Indgift af lapatinib samtidig med stærke inhibitorer af CYP3A4 (fx ritonavir, saquinavir, telithromycin, ketoconazol, itraconazol, voriconazol, posaconazol, nefazodin) bør undgås.
Coadministration of lapatinib with strong inhibitors of CYP3A4 (e. g. ritonavir, saquinavir, telithromycin, ketoconazole, itraconazole, voriconazole, posaconazole, nefazodone) should be avoided.