Provided herein are small molecule compounds that alter the transport activity of solute transporters, particularly urea transporters. The compounds described herein belong to the phenylsulfoxyoxazole, phenylsulfoxyimidazole, phenylsulfoxythiazole class of compounds. The compounds described herein are useful for increasing solute clearance in states of fluid overload and for treating cardiovascular, renal, and metabolic diseases, disorders, and conditions. Methods for identifying and using these agents that inhibit urea transporters are described herein.