In one embodiment, the present application discloses methods of treating diseases and disorders with sulfasalazine, an ABCG2 inhibitor and pharmaceutical formulations of sulfasalazine where the bioavailability of the sulfasalazine is increased. In another embodiment, the present application also provides dosing regimens for treating neurodegenerative diseases and disorders with compositions comprising sulfasalazine and an ABCG2 inhibitor.在一個具體實例中,本申請案揭示藉由柳氮磺胺吡啶、ABCG2抑制劑及柳氮磺胺吡啶之醫藥調配物治療疾病及病症之方法,該柳氮磺胺吡啶之生物可用性在該醫藥調配物中增加。在另一具體實例中,本申請案亦提供藉由包含柳氮磺胺吡啶及ABCG2抑制劑之組成物治療神經退化性疾病及病症之給藥方案。