Human pharmacokinetics and safety evaluation of SonoVue, a new contrast agent for ultrasound imaging.

RATIONALE AND OBJECTIVES. To assess in humans the pharmacokinetics of SonoVue™, a new echo contrast agent based on stabilized sulfur hexafluoride (SF6) microbubbles and to provide additional safety and tolerability information on the compound. METHODS. The blood kinetics and pulmonary elimination of SF6 after intravenous bolus injection of two dosage levels (0.03 and 0.3 mL/kg) of SonoVue™ were evaluated in 12 healthy subjects (7 men, 5 women). In addition, safety and tolerability were evaluated by monitoring vital signs, adverse effects, discomfort, and physical examination and laboratory parameters associated with the SonoVue™ injection. RESULTS. The blood kinetics of SF6 was not dose dependent. SF6 was rapidly removed from the blood by the pulmonary route, with 40% to 50% of the injected dose eliminated within the first minute after administration and 80% to 90% eliminated by 11 minutes after administration; the elimination was similar in men and women and independent of dose. Both dosages were well tolerated. No adverse effects were observed immediately or during the 24-hour follow-up period. CONCLUSIONS. SonoVue™ was shown to be rapidly removed from the blood. The route of SF6 elimination was by means of the lungs in the expired air. SonoVue™ appeared to be safe and well tolerated in healthy subjects.