Provided herein are pyrimido-pyrrolo-quinoxalinedione (PPQ) compounds, and compositions comprising these compounds, that inhibit cystic fibrosis transmembrane conductance regulator (CFTR) mediated ion transport and that are useful for treating diseases and disorders associated with aberrantly increased CFTR chloride channel activity. The compounds, and compositions comprising the compounds, described herein are useful for treating diseases, disorders, and sequelae of diseases, disorders, and conditions that are associated with aberrantly increased CFTR activity, for example, polycystic kidney disease. The compounds may be used for inhibiting expansion or preventing formation of cysts in persons who have polycystic kidney disease.
