2-(1,3-Dihydro-3-oxo-5-sulfo-2H-indol-2-yliden)-3-oxoindolin-5-sulfonsure

Approximately 4-9 minutes after indigotindisulfonate sodium is administered intravenously, its blue color is detectable at the ureteral orifices, enabling easier visualization for accuracy during medical procedures. Although indigotindisulfonic acid and its salt form indigotindisulfonate sodium were initially acknowledged as pharmacologically inert, their use has been associated with cardiovascular effects. Indigotindisulfonate sodium may lead to transient alpha-receptor stimulation, manifested as increased total peripheral vascular resistance, increased diastolic and systolic blood pressure, and increased central venous pressure with decreased cardiac output, stroke volume and heart rate. The use of indigotindisulfonate sodium may lead to severe or life-threatening cardiovascular reactions such as cardiac arrest, arrhythmia, asystole, second-degree atrioventricular block, hypotension, elevation in blood pressure, bradycardia, and tachycardia. Serious anaphylactic reactions with hypotension, dyspnea, bronchospasm, urticaria, or erythema have also been reported. Also, the use of indigotindisulfonate sodium may interfere with light absorption and pulse oximetric methods.

Indigotindisulfonic acid is a biologically inert blue dye. After intravenous injection, indigotindisulfonic acid is excreted by the kidney through tubular secretion and, with its deep blue color, it enhances visualization of the ureteral orifices. Because of this, indigotindisulfonic acid is used to identify ureteral patency in urologic and gynecologic procedures. Indigotindisulfonic acid may lead to the development of hypertension. It has been suggested that indigotindisulfonic acid inhibits endothelium-dependent relaxation at the level of nitric oxide generation and/or its release from the endothelium. Also, indigotindisulfonic acid appears to inhibit vascular guanylyl cyclase in smooth muscle.