Reassess response to treatment every 3 mth. Stop treatment in case no improvement is reached 6 mth after treatment initiation. Continue treatment chronically as long as response is maintained in responders. Eliminate other urologic disorders eg, UTI or bladder cancer. Evaluate patients undergoing invasive procedures or having signs/symptoms of underlying coagulopathy or other increased risk of bleeding (due to treatment w/ other medicinal products influencing coagulation eg, anticoagulants, heparin derivatives, thrombolytic or antiplatelet agents including ASA, or NSAIDs) for hemorrhagic events. Carefully monitor patients who have history of heparin or pentosan polysulfate Na-induced thrombocytopenia; w/ relevant hepatic or renal insufficiency. Retinal pigmentary changes w/ long-term use. Not recommended during pregnancy. Not to be used during breastfeeding. Safety & efficacy has not been established in childn & adolescent <18 yr.