The present invention provides a method of treating edematous retinal disorders. The method comprises administration of a pharmaceutical formulation comprising a hydrolysis-resistant P2Y receptor agonist to stimulate the removal of pathological extraneous fluid from the subretinal and retinal spaces and thereby reduce the accumulation of said fluid associated with retinal detachment and retinal edema. The P2Y receptor agonist can be administered with therapeutic and adjuvant agents commonly used to treat edematous retinal disorders. The present invention also provides a method of treating cystic fibrosis. The present invention further provides P.sup.1-(2'-deoxycytidine 5'-)P.sup.4-(uridine 5'-) tetraphosphate, tetra-(alkali metal) salts such as tetrasodium, tetralithium, tetrapotassium, and mixed (tetra-alkali metal) salts. The present further provides a pharmaceutical formulation comprising a P.sup.1-(2'-deoxycytidine 5'-)P.sup.4-(uridine 5'-) tetraphosphate, tetra-(alkali metal) salt, in a pharmaceutically acceptable carrier.