Although not discussing the comparative safety of Lumason and Definity, the updated 2024 American College of Radiology (ACR) Manual on Contrast Media reported that adverse events from either agent are exceedingly rare. The overall adverse event rate reported in older studies was ~2%, and serious hypersensitivity reactions were reported in 0.01% of patients. Most adverse events are mild and likely physiologic in etiology, including symptoms such as headache, a sensation of warmth or flushing, nausea, and altered taste. There were no reports of death. Most severe reactions occur within 30 minutes of administration and can occur on first or subsequent doses. [1]
A 2017 review discussed the safety data of echocardiographic contrast agents (ECAs). Safety studies have included outpatients, hospitalized patients, patients undergoing stress echocardiography, and those with pulmonary hypertension. There have also been safety statements published by the Food and Drug Administration (FDA) regarding ECAs to soften the safety restrictions of Definity. Overall, the incidence rates of serious allergic reactions from ECAs appear to be minimal (0.004% and 0.009% for serious allergic and anaphylactoid reactions, respectively, as estimated by a meta-analysis of 110,500 patients). These rare allergic reactions are considered the only patient safety risk regarding ultrasound contrast agents. In general, a difference in safety profile between the agents has not been recognized. Direct comparative data between the agents is also limited. [2], [3]
A 2021 comprehensive review article investigated the safety data for use of ECAs in pediatric patients. Their search revealed a total of 57 studies, with the majority (51 studies; n= 4,306) focused on Lumason. Serious adverse events occurred in 10 children in the Lumason studies, with 5 being severe hypersensitivity/anaphylactic reactions. No serious adverse events were reported for children receiving Definity (n= 116). However, these differences can be attributed to the larger dataset available for Lumason. The authors infer that the overall safety profile for ECAs is robust in children with no notable safety alerts among the individual agents. [4]
A 2017 preclinical study detailed a comprehensive in vitro and in vivo comparison of three commercially available ultrasound contrast agents in animals: SonoVue (also marketed as Lumason in the USA), Definity, and Optison. The investigation involved characterizing the physicochemical properties of these agents, as well as evaluating their imaging performance using a Multisizer Coulter Counter for size distribution and microbubble concentration assessments. In vitro contrast enhancements were determined via dose-ranging measurements in a custom-built beaker setup, and in vivo performances were scrutinized using pig and rabbit models, focusing on heart and liver imaging. Findings revealed that the physicochemical characteristics of the agents were consistent with manufacturer specifications, although distinct differences were noted in imaging performance. SonoVue demonstrated superior imaging performance relative to both Definity and Optison. In vitro results showed that SonoVue's echogenicity was similar to or better than Definity's but markedly superior to Optison's, with normalized scattered power up to tenfold higher. In vivo cardiac imaging in pigs corroborated these findings: SonoVue offered longer duration and higher peak enhancement in pig heart imaging compared to Definity. In rabbits, liver imaging indicated comparable performance between SonoVue and Definity, but both outperformed Optison significantly in terms of peak and duration of enhancement. Overall, the article concluded that SonoVue generally exhibited superior imaging performance for the experimental conditions evaluated. [5]
A 2000 multicenter, randomized, placebo-controlled, double-blind trial evaluated the efficacy and safety of the novel ultrasound contrast agent perflutren (Definity) in patients with suboptimal baseline left ventricular echocardiographic images. Conducted at 17 sites, the study enrolled 211 patients with suspected cardiac disease and suboptimal echocardiograms, as indicated by the non-visibility of endocardial borders in two or more segments of the apical four- or two-chamber views. Participants were randomly assigned to receive two intravenous injections of either a placebo (saline) or perflutren at doses of 5 or 10 mL/kg, spaced approximately 30 minutes apart. Echocardiographic images were captured and evaluated for left ventricular opacification and endocardial border enhancement. The results demonstrated that perflutren significantly improved left ventricular cavity opacification, with 87% (5 mL/kg) and 91% (10 mL/kg) of patients displaying clinically useful contrast following administration, compared to 0% in the placebo group (p<0.01). The duration of effective contrast was observed to average 90 seconds. The trial further revealed that perflutren markedly enhanced endocardial border delineation, with 91% of patients showing improvement post-administration versus 12% in the placebo group (p<0.001). This enhancement translated to an average of four additional evaluable segments per patient. Notably, 48% of subjects with nondiagnostic baseline echocardiograms were successfully converted to diagnostic-quality images following perflutren administration. The safety profile of perflutren was comparable to that of the placebo, with no significant adverse effects reported. These findings underscore the potential of perflutren to substantially enhance echocardiographic imaging quality and accuracy in patients with initially poor image conditions, offering a valuable tool for improved cardiac assessment and management. [6]
A 2000 European multicenter, single-blind, cross-over study investigated the efficacy and safety of SonoVue (BR1), a novel echocardiographic contrast agent. This study involved 218 patients with suspected coronary artery disease and was designed to assess SonoVue's ability to enhance the delineation of the left ventricular endocardial border during echocardiographic imaging. Participants received randomized, sequential administrations of four different doses of SonoVue (0.5 ml, 1.0 ml, 2.0 ml, and 4.0 ml) to evaluate dose-dependent improvements in visualization. Each dose was separated by at least a five-minute interval or until the disappearance of the contrast effect. Echocardiographic views were acquired and analyzed by two pairs of off-site observers, blinded to both the doses and patients’ histories. Results demonstrated significant improvement across all doses in endocardial visualization scores compared to baseline echocardiography, particularly in the apical views, with changes being dose-dependent (p<0.001). The highest dose of 4 ml provided the greatest efficacy in endocardial border delineation, with improved diagnostic confidence and image quality post-enhancement. The effective duration of contrast activity increased with dose, ranging from 3.8 ± 2.4 minutes (0.5 mL) to 6.1 ± 3.2 minutes (4 mL). Moreover, SonoVue was effective for patients with suboptimal baseline images, enhancing endocardial visualization significantly. Importantly, the administration of SonoVue was well tolerated, with no significant changes in laboratory parameters, vital signs, or adverse events requiring intervention, indicating both its safety and efficacy in improving echocardiographic imaging in patients with coronary artery disease. [7]
A 2025 nationwide claims analysis of over 11.4 million patients (including 500,073 who received ultrasound enhancing agents for transthoracic or stress echocardiography) directly compared the safety of Definity and Lumason alongside Optison. The study found that serious adverse events within two days of UEA administration were very uncommon. After propensity score matching, patients receiving UEAs had significantly lower odds of death within two days compared to those not receiving contrast (odds ratio 0.23), with no meaningful differences across agents: Definity (OR 0.22), Lumason (OR 0.33), and Optison (OR 0.17). Rates of anaphylaxis, myocardial infarction, ventricular tachycardia, and cardiac arrest were similarly low between UEA recipients and non‑recipients, and no significant differences emerged between Definity and Lumason for any safety outcome. Adverse event rates remained stable across the study period, including before and after the COVID‑19 pandemic. The authors conclude that both Definity and Lumason are associated with continued safety in contemporary practice, and prior reports suggesting differential risks likely reflect selection bias rather than true agent‑specific differences. [8]
A 2025 systematic review and Bayesian network meta-analysis (including 20 studies) compared the safety of the three FDA-approved ultrasound enhancing agents, Optison, Definity, and Lumason, for echocardiography. While the analysis focused primarily on Optison’s favorable profile, direct evidence comparing Definity and Lumason consistently showed potentially lower adverse event rates for Definity. For example, in a large study, serious adverse events occurred in 0.0048% of Definity administrations (7/145,981) versus 0.057% for Lumason (37/64,898); tachycardia occurred in 0% with Definity versus 0.014% with Lumason; and hypotension occurred in 0% with Definity versus 0.031% with Lumason. The network meta-regression for serious adverse events within 30 minutes did not provide a direct odds ratio between Definity and Lumason. Therefore, the evidence suggests that Definity has a more favorable safety profile than Lumason. [9]