Isosulfan Blue

5 WARNINGS AND PRECAUTIONS • Life threatening anaphylactic reactions have occurred after isosulfan blue injection 1% administration. Monitor patients closely for at least 60 minutes after administration of isosulfan blue injection 1% ( 5.1 ). • The admixture of isosulfan blue injection 1% with local anesthetics results in an immediate precipitation of 4% to 9% drug complex. Use a separate syringe for anesthetics ( 5.2 ). • Isosulfan blue injection 1% interferes with measurements in peripheral blood pulse oximetry. Arterial blood gas analysis may be needed ( 5.3 ). 5.1 Hypersensitivity Reactions Life threatening anaphylactic reactions (respiratory distress, shock, angioedema) have occurred after isosulfan blue injection 1% administration. Reactions are more likely to occur in patients with a history of bronchial asthma, allergies, drug reactions or previous reactions to tri-phenylmethane dyes. Monitor patients closely for at least 60 minutes after administration of isosulfan blue injection 1%. Trained personnel should be available to administer emergency care including resuscitation. 5.2 Precipitation of Isosulfan Blue Injection 1% by Lidocaine The admixture of isosulfan blue injection 1% (with local anesthetics (i.e. lidocaine)) in the same syringe results in an immediate precipitation of 4% to 9% drug complex. Use a separate syringe to administer a local anesthetic. 5.3 Interference with Oxygen Saturation and Methemoglobin Measurements Isosulfan blue injection 1% interferes with measurements of oxygen saturation in peripheral blood by pulse oximetry and can cause falsely low readings. The interference effect is maximal at 30 minutes and minimal generally by 4 hours after administration. Arterial blood gas analysis may be needed to verify decreased arterial partial pressure of oxygen. Isosulfan blue injection 1% may also cause falsely elevated readings of methemoglobin by arterial blood gas analyzer. Therefore, cooximetry may be needed to verify methemoglobin level.