PRECAUTIONS General Diagnostic procedures which involve the use of radiopaque diagnostic agents should be carried out under the direction of personnel with the prerequisite training and with a thorough knowledge of the particular procedure to be performed. Appropriate facilities should be available for coping with any complication of the procedure, as well as for emergency treatment of severe reactions to the contrast agent itself. After administration of the radiocontrast agent, competent personnel and emergency facilities should be available for at least 30 to 60 minutes since delayed reactions have occurred (see ADVERSE REACTIONS ). The possibility of an idiosyncratic reaction in susceptible patients should always be considered (see ADVERSE REACTIONS ). The susceptible population includes patients with a history of a previous reaction to a contrast medium, patients with a known sensitivity to iodine per se and patients with a known clinical hypersensitivity: bronchial asthma, hay fever and food allergies. A positive history of allergies or hypersensitivity does not arbitrarily contraindicate the use of a contrast agent where a diagnostic procedure is thought essential, but caution should be exercised (see ADVERSE REACTIONS ). Premedication with antihistamines or corticosteroids to avoid or minimize possible allergic reactions in such patients should be considered. Recent reports indicate that such pre-treatment does not prevent serious life-threatening reactions, but may reduce both their incidence and severity. Since these procedures require instrumentation, special precautions should be observed in those patients known to have an acute urinary tract infection. Filling of the bladder should be done at a steady rate, exercising caution to avoid excessive pressure. Sterile procedures should be employed in administration. Carcinogenesis, Mutagenesis, Impairment of Fertility No long-term animal studies have been performed to evaluate carcinogenic potential, mutagenic potential or whether this drug affects fertility in males or females. Use in Pregnancy Category C. Animal reproduction studies have not been conducted with Cysto-Conray II. It is also not known whether this drug can cause fetal harm when administered to a pregnant woman or can affect reproduction capacity. Cysto-Conray II should be used in pregnant women only if clearly needed. Nursing Mothers Iothalamate salts are excreted unchanged in human milk. Although it has not been established that serious adverse reactions occur in nursing infants, because of the potential for adverse reactions, caution should be exercised when Cysto-Conray II is administered to a nursing woman. Information for the Patient Patients receiving diagnostic agents for instillation urography should be instructed to: Inform your physician if you are pregnant. Inform your physician if you are allergic to any food, drugs or dyes used for x-ray procedures (see PRECAUTIONS, General ). Consult with your physician if, at some future date, any thyroid tests are planned. The iodine in this agent may interfere with later thyroid tests. Inform your physician about any other medications you are currently taking. Drug/Laboratory Test Interaction Thyroid Function Tests – If indicated, these tests generally should be performed prior to the administration of any iodinated agent. However, thyroid function can be evaluated after use of these agents by using T3 resin uptake or free thyroxine assays.