What is Definity and how is it used?
Definity (perflutren lipid microsphere) Injectable Suspension is a contrast agent used to brighten and clarify images of the heart during echocardiograms.
What are side effects of Definity?
Common side effects of Definity include:
- injection site reactions,
- back and chest pain,
- hot flashes,
- fast or slow heart rate,
- high or low blood pressure,
- dry mouth,
- abdominal pain,
- joint pain,
- leg cramps,
- spinning sensation (vertigo),
- numbness and tingling,
- sore throat,
- runny or stuffy nose,
- shortness of breath,
- increased sweating, and
- dry skin.
SERIOUS CARDIOPULMONARY REACTIONS
Serious cardiopulmonary reactions, including fatalities, have occurred uncommonly during or following perflutren-containing microsphere administration [see WARNINGS AND PRECAUTIONS]. Most serious reactions occur within 30 minutes of administration.
DEFINITY (Perflutren Lipid Microsphere) Injectable Suspension is an ultrasound contrast agent. The DEFINITY vial contains components that upon activation yield perflutren lipid microspheres. The vial contains a clear, colorless, sterile, non-pyrogenic, hypertonic liquid, which upon activation with the aid of a VIALMIX, provides a homogeneous, opaque, milky white injectable suspension of perflutren lipid microspheres. The suspension of activated DEFINITY is administered by intravenous injection.
The perflutren lipid microspheres are composed of octafluoropropane encapsulated in an outer lipid shell consisting of (R) - hexadecanoic acid, 1-[(phosphonoxy)methyl]-1,2ethanediyl ester, monosodium salt (abbreviated DPPA); (R) - 4-hydroxy-N,N,N-trimethyl10-oxo-7-[(1-oxohexadecyl)oxy]-3,4,9-trioxa-4-phosphapentacosan-1-aminium, 4-oxide, inner salt (abbreviated DPPC); and (R)-∝-[6-hydroxy-6-oxido-9-[(1-oxohexadecyl)oxy]5,7,11-trioxa-2-aza-6-phosphahexacos-1-yl]-ω-methoxypoly(ox-1,2-ethanediyl), monosodium salt (abbreviated MPEG5000 DPPE).
Octafluoropropane is chemically characterized as 1,1,1,2,2,3,3,3-octafluoropropane. It has a molecular weight of 188, empirical formula of C3F8 and has the following structural formula:
DPPA has a molecular weight of 670, empirical formula of C35H68O8PNa, and following structural formula:
DPPC has a molecular weight of 734, empirical formula of C40H80NO8P, and following structural formula:
MPEG5000 DPPE has an approximate molecular weight of 5750 represented by empirical formula C265H527NO123PNa, and the following structural formula:
Prior to VIALMIX activation, the DEFINITY vial contains 6.52 mg/mL octafluoropropane in the headspace. Each mL of the clear liquid contains 0.75 mg lipid blend (consisting of 0.045 mg DPPA, 0.401 mg DPPC, and 0.304 mg MPEG5000 DPPE), 103.5 mg propylene glycol, 126.2 mg glycerin, 2.34 mg sodium phosphate monobasic monohydrate, 2.16 mg sodium phosphate dibasic heptahydrate, and 4.87 mg sodium chloride in Water for Injection. The pH is 6.2-6.8.
After activating the contents of the vial in a VIALMIX, each mL of the milky white suspension contains a maximum of 1.2 X 1010 perflutren lipid microspheres, and about 150 microL/mL (1.1 mg/mL) octafluoropropane. The microsphere particle size parameters are listed in Table 2 below:
Table 2 : Microsphere Size Distribution
|Microsphere particle size parameters|
|Mean diameter range||1.1 μm – 3.3 μm|
|Percent less than 10||98%|
|Maximum diameter||20 μm|
Activated DEFINITY (Perflutren Lipid Microsphere) Injectable Suspension is indicated for use in patients with suboptimal echocardiograms to opacify the left ventricular chamber and to improve the delineation of the left ventricular endocardial border.
DOSAGE AND ADMINISTRATION
Important Administration Instructions
- DEFINITY is intended for administration only after activation in the VIALMIX apparatus. Before injection, this product must be activated and prepared according to the instructions outlined below. The VIALMIX apparatus should be ordered from Lantheus Medical Imaging, 331 Treble Cove Road, North Billerica, MA, 01862. For customer orders call 1-800-299-3431.
- DEFINITY may be injected by either an intravenous (IV) bolus or infusion. Do not administer DEFINITY by intra-arterial injection [see WARNINGS AND PRECAUTIONS].
- The maximum dose is either two bolus doses or one single intravenous infusion. The safety of bolus and infusion dosing in combination or in sequence, has not been studied.
The recommended bolus dose for activated DEFINITY is 10 microliters (microL)/kg of the activated product by intravenous bolus injection within 30-60 seconds, followed by a 10 mL saline flush. If necessary, a second 10 microliters (microL)/kg dose followed by a second 10 mL saline flush may be administered 30 minutes after the first injection to prolong contrast enhancement.
The recommended infusion dose for activated DEFINITY is via an IV infusion of 1.3 mL added to 50 mL of preservative-free saline. The rate of infusion should be initiated at 4.0 mL/minute, but titrated as necessary to achieve optimal image enhancement, not to exceed 10 mL/minute.
After baseline non-contrast echocardiography is completed, set the mechanical index for the ultrasound device at 0.8 or below [see WARNINGS AND PRECAUTIONS]. Then inject activated DEFINITY (as described above) and begin ultrasound imaging immediately. Evaluate the activated DEFINITY echocardiogram images in combination with the non-contrast echocardiogram images.
In a crossover trial of 64 patients randomized to both bolus and infusion, the duration of clinically useful contrast enhancement for fundamental imaging was approximately 3.4 minutes after a 10 microL/kg bolus and was approximately 7.1 minutes during the continuous infusion of 1.3 mL activated DEFINITY in 50 mL saline at a rate of 4 mL/min.
DEFINITY Activation, Preparation And Handling Instructions
- Allow the vial to warm to room temperature before starting the activation procedure.
- Activate DEFINITY by shaking the vial for 45 seconds
using a VIALMIX.
Note: illustrations of this procedure are contained in the VIALMIX User's Guide.
Do not use this drug unless it has completed a full 45 second activation cycle in the VIALMIX. DEFINITY will not be properly activated unless the full 45 second activation cycle is completed. Do not reactivate the vial if VIALMIX did not complete a full 45 second cycle. Do not reactivate a successfully activated DEFINITY vial (see step 3). Do not use a VIALMIX that is not functioning properly. Refer to the VIALMIX User's Guide for the “VIALMIX calibration and replacement procedures” to ensure that a properly functioning VIALMIX is used.
- Immediately after activation in the VIALMIX, activated DEFINITY appears as a milky white suspension and may be used immediately after activation. If the product is not used within 5 minutes of VIALMIX activation, the microspheres should be resuspended by 10 seconds of hand agitation by inverting the vial before the product is withdrawn in a syringe. The activated DEFINITY may be used for up to 12 hours from the time of VIALMIX, but only after the microspheres are resuspended by hand agitation. Store the activated DEFINITY at room temperature in the original product vial.
- Invert the vial and withdraw the activated milky white suspension using the Intellipin (Dispensing Pin), the PINSYNC (Vented Vial Adapter 13mm), or 18 to 20 gauge syringe needle. Withdraw the material from the middle of the liquid in the inverted vial. Do not inject air into the DEFINITY Vial.
- Use the product immediately after its withdrawal from the vial; do not allow the product to stand in the syringe.
For single use only: DEFINITY does not contain bacterial preservative. Bacterial contamination with the risk of post-administration septicemia can occur following the puncture of the elastomeric septum. It is essential to follow directions for activation of DEFINITY carefully and to adhere to strict aseptic procedures during preparation.
Dosage Forms And Strengths
DEFINITY is supplied as a single use 2-mL clear glass vial containing a clear liquid in packages of four (4) and sixteen (16) single-use vials.
Prior to activation, the headspace of each vial contains 6.52 mg/mL octafluoropropane and the clear liquid contains 0.75mg/mL of a lipid blend. After activation, each vial contains a maximum of 1.2 X 1010 perflutren lipid microspheres, and about 150 microL/mL (1.1 mg/mL) octafluoropropane [see DESCRIPTION].
DEFINITY is supplied as a single use 2-mL clear glass vial containing clear liquid in packages of four (4) and sixteen (16) single-use vials.
One (1) 2mL vial -NDC (11994-011-01)
Four (4) 2mL vials per kit - NDC (11994-011-04)
Sixteen (16) 2mL vials per kit - NDC (11994-011-16)
Storage And Handling
Store between 2-8°C (36°-46°F).
Distributed By Lantheus Medical Imaging 331 Treble Cove Road N. Billerica, Massachusetts 01862 USA. For ordering, tel. toll free: 800-299-3431. All Other Business: 800-362-2668 (For Massachusetts and International, call 978-667-9531). Revised: Jan 2017
The following serious adverse reactions are described elsewhere in the labeling:
- Serious Cardiopulmonary Reactions [see WARNINGS AND PRECAUTIONS]
- Hypersensitivity Reactions [see WARNINGS AND PRECAUTIONS]
Clinical Trials Experience
Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.
A total of 1716 subjects were evaluated in pre-market clinical trials of activated DEFINITY. In this group, 1063 (61.9%) were male and 653 (38.1%) were female, 1328 (77.4%) were White, 258 (15.0%) were Black, 74 (4.3%) were Hispanic, and 56 (3.3%) were classified as other racial or ethnic groups. The mean age was 56.1 years (range 18 to 93). Of these, 144 (8.4%) had at least one adverse reaction (Table 1). There were 26 serious adverse events and 15 (0.9%) subjects discontinued because of an adverse event.
Serious Adverse Reactions
Among the 1716 study patients, 19 (1.1%) suffered serious cardiopulmonary adverse reactions.
For all adverse reactions, the overall incidence of adverse experiences was similar for the < 65 year age group and the > 65 year age group, similar in males and in females, similar among all racial or ethnic groups, and similar for bolus and infusion dosing. Table 1 summarizes the most common adverse reactions.
Table 1 : New-Onset Adverse Reactions Occurring in
≥ 0.5% of All DEFINITY-Treated Subjects
|Total Number of Adverse Reactions||269|
|Total Number of Subjects with an Adverse Reaction||144 (8.4%)|
|Preferred term||n (%)|
|Application Site Disorders||11 (0.6)|
|Injection Site Reactions||11 (0.6)|
|Body as a Whole||41 (2.4)|
|Back/renal pain||20 (1.2)|
|Chest pain||13 (0.8)|
|Central and peripheral nervous system disorder||54 (3.1)|
|Gastrointestinal system||31 (1.8)|
|Vascular (extracardiac) disorders||19 (1.1)|
|N=Sample size 1716 subjects who received activated
n=Number of subjects reporting at least one Adverse Reaction
Other adverse reactions that occurred in ≤ 0.5% of the activated DEFINITY-dosed subjects were:
Body as a Whole: Fatigue, fever, hot flushes, pain, rigors, and syncope
Platelet, Bleeding, and Clotting: Hematoma
Special Senses: Decreased hearing, conjunctivitis, abnormal vision and taste perversion
In a prospective, multicenter, open-label registry of 1053 patients receiving DEFINITY in routine clinical practice, heart rate, respiratory rate, and pulse oximetry were monitored for 30 minutes after DEFINITY administration. No deaths or serious adverse reactions were reported, suggesting that these reactions are unlikely to occur at a rate of more than 0.3% when DEFINITY is used according to recommendations.
The following adverse reactions have been identified during the post-marketing use of perflutren-containing microsphere products. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.
Fatal cardiopulmonary and hypersensitivity reactions and other serious but non-fatal adverse reactions were uncommonly reported. These reactions typically occurred within 30 minutes of DEFINITY administration. These serious reactions may be increased among patients with unstable cardiopulmonary conditions (acute myocardial infarction, acute coronary artery syndromes, worsening or unstable congestive heart failure, or serious ventricular arrhythmias [see WARNINGS AND PRECAUTIONS].
Reported reactions included:
Fatal cardiac or respiratory arrest, shock, syncope, symptomatic arrhythmias (atrial fibrillation, tachycardia, bradycardia, supraventricular tachycardia, ventricular fibrillation, ventricular tachycardia), hypertension, hypotension, dyspnea, hypoxia, chest pain, respiratory distress, stridor, wheezing.
Anaphylactic reaction, anaphylactic shock, bronchospasm, throat tightness, angioedema, edema (pharyngeal, palatal, mouth, peripheral, localized), swelling (face, eye, lip, tongue, upper airway), facial hypoesthesia, rash, urticaria, pruritus, flushing, erythema.
No information provided.
Included as part of the PRECAUTIONS section.
Serious Cardiopulmonary Reactions
Serious cardiopulmonary reactions including fatalities have occurred uncommonly during or shortly following perflutren-containing microsphere administration, typically within 30 minutes of administration. The risk for these reactions may be increased among patients with unstable cardiopulmonary conditions (acute myocardial infarction, acute coronary artery syndromes, worsening or unstable congestive heart failure, or serious ventricular arrhythmias). Always have cardiopulmonary resuscitation personnel and equipment readily available prior to DEFINITY administration and monitor all patients for acute reactions.
The reported reactions include: fatal cardiac or respiratory arrest, shock, syncope, symptomatic arrhythmias (atrial fibrillation, tachycardia, bradycardia, supraventricular tachycardia, ventricular fibrillation, ventricular tachycardia), hypertension, hypotension, dyspnea, hypoxia, chest pain, respiratory distress, stridor, wheezing, loss of consciousness, and convulsions [see ADVERSE REACTIONS].
In postmarketing use, serious hypersensitivity reactions were observed during or shortly following perflutren-containing microsphere administration including:
Shock, bronchospasm, throat tightness, angioedema, edema (pharyngeal, palatal, mouth, peripheral, localized), swelling (face, eye, lip, tongue, upper airway), facial hypoesthesia, rash, urticaria, pruritus, flushing, and erythema have occurred in patients with no prior exposure to perflutren-containing microsphere products [see ADVERSE REACTIONS]. Always have cardiopulmonary resuscitation personnel and equipment readily available prior to DEFINITY administration and monitor all patients for hypersensitivity reactions.
When administering DEFINITY to patients with a cardiac shunt, the microspheres can bypass filtering by the lung and enter the arterial circulation. Assess patients with shunts for embolic phenomena following DEFINITY administration. DEFINITY is only for intravenous administration; do not administer DEFINITY by intra-arterial injection [see DOSAGE AND ADMINISTRATION].
Ventricular Arrhythmia Related To High Mechanical Index
High ultrasound mechanical index values may cause microsphere cavitation or rupture and lead to ventricular arrhythmias. Additionally, end-systolic triggering with high mechanical indices has been reported to cause ventricular arrhythmias. DEFINITY is not recommended for use at mechanical indices greater than 0.8 [see DOSAGE AND ADMINISTRATION].
Carcinogenesis, Mutagenesis, And Impairment Of Fertility
Studies with activated DEFINITY have not been performed to evaluate carcinogenic potential. Evidence of genotoxicity was not found in the following studies with activated DEFINITY: 1) bacterial mutagenesis assay (Ames assay), 2) in vitro mammalian mutagenesis assay, 3) in vitro human lymphocyte chromosome aberration assay, and 4) in vivo rat micronucleus assay.
Impairment of male or female fertility was not observed in rats and rabbits treated with activated DEFINITY at doses up to 24 and 15 times the human dose based on body surface area (in rats and rabbits respectively).
Use In Specific Populations
Pregnancy Category B
There are no adequate and well-controlled studies of DEFINITY in pregnant women. Reproduction studies performed in rats and rabbits at doses up to 24 and 15 times the human dose based on body surface area (in rats and rabbits respectively) revealed no evidence of impaired fertility or harm to the fetus due to DEFINITY. Because animal reproduction studies are not always predictive of human response, this drug should be used during pregnancy only if clearly needed.
It is not known whether DEFINITY is excreted in human milk. Based on the rapid clearance of this drug, advise nursing mothers to pump and discard breast milk once after treatment [see CLINICAL PHARMACOLOGY]. Because many drugs are excreted in human milk, caution should be exercised when DEFINITY is administered to a nursing mother.
The safety and effectiveness of activated DEFINITY have not been established in the pediatric population.
The safety of injecting activated DEFINITY in neonates and infants with immature pulmonary vasculature has not been studied.
The pharmacokinetics of activated DEFINITY in pediatric subjects has not been studied.
In clinical trials, the overall incidence of adverse reactions was similar for the < 65 year age group and the ≥ 65 year age group. Of the total number of subjects in clinical trials of DEFINITY, 144 (33%) were 65 and over. No overall differences in safety or effectiveness were observed between these subjects and younger subjects, and other reported clinical experience has not identified differences in responses between the elderly and younger patients, but greater sensitivity of some older individuals cannot be ruled out.
No information provided.
Do not administer DEFINITY to patients with known or suspected:
- Hypersensitivity to perflutren [see WARNINGS AND PRECAUTIONS].
Mechanism Of Action
Perflutren lipid microspheres exhibit lower acoustic impedance than blood and enhance the intrinsic backscatter of blood. These physical acoustic properties of activated DEFINITY provide contrast enhancement of the left ventricular chamber and aid delineation of the left ventricular endocardial border during echocardiography.
In animal models the acoustic properties of activated DEFINITY were established at or below a mechanical index of 0.7 (1.8 MHz frequency). In clinical trials, the majority of the patients were imaged at or below a mechanical index of 0.8.
Human pharmacokinetics information is not available for the intact or degassed lipid microspheres. The pharmacokinetics of octafluoropropane gas (OFP) was evaluated in healthy subjects (n=8) after the IV administration of activated DEFINITY at a 50 microL/kg dose.
OFP gas binding to plasma proteins or partitioning into blood cells has not been studied. However, OFP protein binding is expected to be minimal due to its low partition coefficient into whole blood.
OFP is a stable gas that is not metabolized. The phospholipid components of the microspheres are thought to be metabolized to free fatty acids.
OFP was not detectable after 10 minutes in most subjects either in the blood or in expired air. OFP concentrations in blood were shown to decline in a mono-exponential fashion with a mean half-life of 1.3 minutes in healthy subjects.
The pharmacokinetics of octafluoropropane gas (OFP) was evaluated in subjects (n=11) with chronic obstructive pulmonary disease (COPD). The mean half-life of OFP in blood was 1.9 minutes. The total lung clearance of OFP was similar to that in healthy subjects.
The pharmacokinetics of activated DEFINITY has not been studied in subjects with hepatic diseases or congestive heart failure.
A total of 249 subjects were evaluated in clinical trials (208 received activated DEFINITY and 41 placebo). In this group, 154 (61.8%) were male and 95 (38.2%) were female; 183 (73.5%) were White, 38 (15.3%) were Black, 21 (8.4%) were Hispanic, and 7 (2.8%) were classified as other racial or ethnic groups. The mean age was 53.9 years (range 18 to 87).
Activated DEFINITY was evaluated in four controlled clinical trials: Two open-label baseline controlled, unpaired blinded image evaluation studies and two identical placebo-controlled, unpaired blinded image evaluation studies. Subjects were eligible for these studies if they had two or more (of six) non-evaluable segments in either the apical 2-or 4chamber view in non-contrast fundamental echocardiography.
In the baseline controlled studies, a total of 126 (67 in study A and 59 in study B) subjects received a bolus dose of 10 microL/kg activated DEFINITY. The outcome measures in these studies included the blinded assessment of ejection fraction (EF), endocardial border length (EBL) obtained by direct measurement, and qualitative assessment of wall motion.
In the two placebo-controlled studies a total of 123 subjects were randomized in 1:2 ratio to receive two IV bolus doses of either saline (placebo) or activated DEFINITY 10 microL/kg (17 placebo vs. 33 activated DEFINITY patients and 24 placebo vs. 49 activated DEFINITY patients, respectively). The outcome measure for assessing the effectiveness of activated DEFINITY was the blinded assessment of improvement in ventricular chamber enhancement (measured by videodensitometry at end-diastole and end-systole).
Endocardial Border Length
As shown in Table 3, compared to baseline, a single bolus dose of 10 microL/kg of activated DEFINITY increased the length of endocardial border that could be measured at both end-systole and end-diastole. The mean change in border length from baseline at end-diastole was statistically significant for all readers in the apical 4-chamber view and for 3 out of 4 readers for the apical 2-chamber view. The mean change in border length from baseline at end-systole was statistically significant for 3 out of 4 readers for the apical 4-chamber view and for 2 out of 4 readers for the apical 2-chamber view.
Ventricular Chamber Enhancement
Left ventricular chamber enhancement after an activated DEFINITY dose of 10 microL/kg was significantly increased from baseline compared to placebo in both views at the mid-ventricular and apical levels at end-diastole. Similar results were noted at end-systole, with the exception of the 4-chamber view.
In a retrospective analysis, in a subset of subjects (n=12 to 47, depending on reader) having at least 2 adjacent segments non-evaluable on non-contrast imaging, activated DEFINITY converted a baseline non-evaluable image to an evaluable image in 58 to 91% of the patients, depending on the reader. In the converted images, the accuracy of wall motion (i.e., normal versus abnormal) improved in 42 to 71% of the patients, depending on the reader, however, improvement in the specific diagnostic accuracy (e.g., hypokinetic, akinetic etc.) was not established. Also, in 13 to 37% of the patients, depending on the reader, activated DEFINITY was found to obscure the wall motion rendering the image non-evaluable.
In the 2 baseline controlled studies, ejection fraction results were evaluated in comparison to MRI. The results were evaluated by 3 blinded, independent radiologists. In these studies, although there was a statistically significant increase in ventricular chamber enhancement, activated DEFINITY did not significantly improve the assessment of ejection fraction compared to the baseline images.
Table 3 : MEAN (SD) ENDOCARDIAL BORDER LENGTH (CM) BY
BOTH APICAL 2-AND 4-CHAMBER VIEWS AT END-SYSTOLE AND END-DIASTOLE BY STUDY,
|Study/View||Endocardial Border Length - Blinded Read|
|Mean(SD) at End-Diastole||Mean(SD) at End-Systole|
|Reader 1||Reader 2||Reader 1||Reader 2|
|Studv A: (N = 67)|
|Study B: (N = 59)|
|Activated DEFINITY Bolus Dose = 10 μL/kg
* Significant change from baseline (paired t-test, p < 0.05)
In an open administration, crossover trial, 64 patients were randomized to receive both bolus (10 microL/kg) and infusion (1.3 mL activated DEFINITY in 50 mL saline at the rate of 4 mL/min) dosing of activated DEFINITY. Outcome measures for this study included clinically useful ventricular cavity enhancement and endocardial border length. Similar results were seen as described above.
Optimal activated DEFINITY doses and device settings for harmonic imaging have not been established.
Pulmonary Hemodynamic Effects
The impact of DEFINITY on pulmonary hemodynamics was explored in a prospective, open-label study of patients with normal ( ≤ 35 mmHg, 16 patients) and elevated ( > 35 mmHg, < 75 mmHg, 16 patients) pulmonary artery systolic pressure undergoing right heart catheterization. Patients with pulmonary artery systolic pressure greater than 75 mmHg were excluded from this study. Systemic hemodynamic parameters and ECGs were also evaluated. No clinically important pulmonary hemodynamic, systemic hemodynamic, or ECG changes were observed. This study did not assess the effect of DEFINITY on visualization of cardiac or pulmonary structures.
Advise patients to inform their healthcare provider if they develop any symptoms of hypersensitivity after DEFINITY administration, including rash, wheezing, or shortness of breath.
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