Dexmedetomidine Hcl 100 Mcg/ml Injectable Solution
- RECENT MAJOR CHANGES
- 1 INDICATIONS AND USAGE
- 2 DOSAGE AND ADMINISTRATION
- 3 DOSAGE FORMS AND STRENGTHS
- 4 CONTRAINDICATIONS
- 5 WARNINGS AND PRECAUTIONS
- 6 ADVERSE REACTIONS
- 7 DRUG INTERACTIONS
- 8 USE IN SPECIFIC POPULATIONS
- 9 DRUG ABUSE AND DEPENDENCE
- 10 OVERDOSAGE
- 11 DESCRIPTION
- 12 CLINICAL PHARMACOLOGY
- 13 NONCLINICAL TOXICOLOGY
- 14 CLINICAL STUDIES
- 16 HOW SUPPLIED/STORAGE AND HANDLING
- 17 PATIENT COUNSELING INFORMATION
- SPL UNCLASSIFIED
RECENT MAJOR CHANGES
1 INDICATIONS AND USAGE
1.1 Intensive Care Unit Sedation
1.2 Procedural Sedation
2 DOSAGE AND ADMINISTRATION
2.1 Administration Instructions
- Individualize and titrate dosing to desired clinical response.
- Administer by continuous intravenous infusion using a controlled infusion device.
- Administration duration should not exceed 24 hours [see Warnings and Precautions (5.5, 5.6)].
- Dexmedetomidine Injection must be diluted prior to administration [see Dosage and Administration (2.4)].
- Dexmedetomidine Injection should be administered only by health care providers skilled in the management of patients in the intensive care or operating room setting.
- Continuously monitor blood pressure, heart rate and oxygen levels during the use of Dexmedetomidine Injection as clinically appropriate after discontinuation.
- Dexmedetomidine Injection has been continuously infused in mechanically ventilated adult patients prior to extubation, during extubation, and post extubation. It is not necessary to discontinue Dexmedetomidine Injection.
- Use administration components made with synthetic or coated natural rubber gaskets. Dexmedetomidine Injection has the potential for absorption into some types of natural rubber.
2.2 Recommended Dosage
|
INDICATION
|
DOSAGE AND ADMINISTRATION
|
|
Initiation of Intensive Care Unit Sedation
|
For adult patients: a loading infusion of one mcg/kg over 10 minutes . For adult patients being converted from alternate sedative therapy: a loading dose may not be required. For patients over 65 years of age: Consider a dose reduction [see Use in Specific Populations (8.5)] . For adult patients with impaired hepatic function: Consider a dose reduction [see Use in Specific Populations (8.6), Clinical Pharmacology (12.3)] . |
|
Maintenance of Intensive Care Unit Sedation
|
For adult patients: a maintenance infusion of 0.2 to 0.7 mcg/kg/hour . The rate of the maintenance infusion should be adjusted to achieve the desired level of sedation. For patients over 65 years of age: Consider a dose reduction [see Use in Specific Populations (8.5)]. For adult patients with impaired hepatic function: Consider a dose reduction [see Use in Specific Populations (8.6), Clinical Pharmacology (12.3)] |
|
Initiation of Procedural Sedation
|
For adult patients: a loading infusion of one mcg/kg over 10 minutes . For less invasive procedures such as ophthalmic surgery, a loading infusion of 0.5 mcg/kg given over 10 minutes may be suitable. For awake fiberoptic intubation in adult patients: a loading infusion of one mcg/kg over 10 minutes . For patients over 65 years of age: a loading infusion of 0.5 mcg/kg over 10 minutes [see Use in Specific Populations (8.5)]. For adult patients with impaired hepatic function: Consider a dose reduction [see Use in Specific Populations (8.6), Clinical Pharmacology (12.3)] . |
|
Maintenance of Procedural Sedation
|
For adult patients: the maintenance infusion is generally initiated at 0.6 mcg/kg/hour and titrated to achieve desired clinical effect with doses ranging from 0.2 to 1 mcg/kg/hour . Adjust the rate of the maintenance infusion to achieve the targeted level of sedation. For awake fiberoptic intubation in adult patients: a maintenance infusion of 0.7 mcg/kg/hour is recommended until the endotracheal tube is secured. For patients over 65 years of age: Consider a dose reduction [see Use in Specific Populations (8.5)]. For adult patients with impaired hepatic function: Consider a dose reduction [see Use in Specific Populations (8.6), Clinical Pharmacology (12.3)] . |
2.3 Dosage Adjustment
2.4 Preparation of Solution
Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit. Do not use if product is discolored or if precipitate matter is present.
Dexmedetomidine Injection, 400 mcg/4 mL (100 mcg/mL) and 1000 mcg/10 mL (100 mcg/mL)
Dexmedetomidine Injection must be diluted with 0.9% sodium chloride injection to achieve required concentration (4 mcg/mL) prior to administration. Preparation of solutions is the same, whether for the loading dose or maintenance infusion.
To prepare the solution, do one of the following:
- Withdraw 2 mL of Dexmedetomidine Injection, and add to 48 mL of 0.9% Sodium Chloride Injection to a total volume of 50 mL or
- Withdraw 4 mL of Dexmedetomidine Injection, and add to 96 mL of 0.9% Sodium Chloride Injection to a total of volume of 100 mL
Prior to use, may store the diluted dexmedetomidine solution for up to 4 hours at room temperature or up to 24 hours at 2o to 8oC.
Discard unused portion.
2.5 Administration with Other Fluids
Dexmedetomidine Injection has been shown to be incompatible when administered with the following drugs: amphotericin B, diazepam.
Dexmedetomidine Injection is compatible with and may be co- administered with:
- 0.9% Sodium Chloride Injection
- 5% Dextrose Injection in water
- 20% Mannitol Injection
- Lactated Ringer's Injection
- 100 mg/mL Magnesium Sulfate Injection
- 0.3% potassium chloride solution
2.6 Compatibility with Natural Rubber
3 DOSAGE FORMS AND STRENGTHS
- 400 mcg/4 mL (100 mcg/mL) in a multiple-dose vial
- 1000 mcg in 10 mL in a multiple-dose vial
4 CONTRAINDICATIONS
5 WARNINGS AND PRECAUTIONS
5.1 Drug Administration
5.2 Hypotension, Bradycardia, and Sinus Arrest
Reports of hypotension and bradycardia have been associated with dexmedetomidine infusion. Some of these cases have resulted in fatalities. If medical intervention is required, treatment may include decreasing or stopping the infusion of dexmedetomidine, increasing the rate of intravenous fluid administration, elevation of the lower extremities, and use of pressor agents. Because dexmedetomidine has the potential to augment bradycardia induced by vagal stimuli, clinicians should be prepared to intervene. The intravenous administration of anticholinergic agents (e.g., glycopyrrolate, atropine) should be considered to modify vagal tone. In clinical trials, glycopyrrolate or atropine were effective in the treatment of most episodes of dexmedetomidine-induced bradycardia. However, in some patients with significant cardiovascular dysfunction, more advanced resuscitative measures were required.
Caution should be exercised when administering dexmedetomidine to patients with advanced heart block and/or severe ventricular dysfunction. Because dexmedetomidine decreases sympathetic nervous system activity, hypotension and/or bradycardia may be expected to be more pronounced in patients with hypovolemia, diabetes mellitus, or chronic hypertension and in elderly patients.
In clinical trials where other vasodilators or negative chronotropic agents were co-administered with dexmedetomidine an additive pharmacodynamic effect was not observed. Nonetheless, caution should be used when such agents are administered concomitantly with dexmedetomidine.
5.3 Transient Hypertension
5.4 Arousability
5.5 Withdrawal
With administration up to 7 days, regardless of dose, 12 (5%) dexmedetomidine injection adult subjects experienced at least 1 event related to withdrawal within the first 24 hours after discontinuing study drug and 7 (3%) dexmedetomidine injection adult subjects experienced at least 1 event 24 to 48 hours after end of study drug. The most common events were nausea, vomiting, and agitation [see Adverse Reactions (6.1)].
In adult subjects, tachycardia and hypertension requiring intervention in the 48 hours following study drug discontinuation occurred at frequencies of <5%.
Procedural Sedation
In adult subjects, withdrawal symptoms were not seen after discontinuation of short-term infusions of dexmedetomidine (<6 hours).
In pediatric patients, mild transient withdrawal symptoms of emergence delirium or agitation were seen after discontinuation of short-term infusions of dexmedetomidine (<2 hours).
5.6 Tolerance and Tachyphylaxis
5.7 Hyperthermia or Pyrexia
5.8 Hepatic Impairment
6 ADVERSE REACTIONS
- Hypotension, bradycardia and sinus arrest [see Warnings and Precautions (5.2)]
- Transient hypertension [see Warnings and Precautions (5.3)]
6.1 Clinical Trials Experience
Most common treatment-emergent adverse reactions, occurring in greater than 2% of adult patients in both Intensive Care Unit and procedural sedation studies include hypotension, bradycardia and dry mouth.
Intensive Care Unit Sedation
Adverse reaction information is derived from the continuous infusion trials of dexmedetomidine injection for sedation in the Intensive Care Unit setting in which 1,007 adult patients received dexmedetomidine injection. The mean total dose was 7.4 mcg/kg (range: 0.8 to 84.1), mean dose per hour was 0.5 mcg/kg/hr (range: 0.1 to 6.0) and the mean duration of infusion of 15.9 hours (range: 0.2 to 157.2). The population was between 17 to 88 years of age, 43% ≥65 years of age, 77% male and 93% Caucasian. Treatment-emergent adverse reactions occurring at an incidence of >2% are provided in Table 2. The most frequent adverse reactions were hypotension, bradycardia and dry mouth [see Warnings and Precautions (5.2)].
Table 2: Adverse Reactions with an Incidence >2%— Adult Intensive Care Unit Sedation Population <24 hours*
|
Adverse Event |
All Dexmedetomidine
Injection (N = 1007) (%) |
Randomized Dexmedetomidine
Injection (N = 798) (%) |
Placebo
(N = 400) (%) |
Propofol
(N = 188) (%) |
| Hypotension |
25% |
24% |
12% |
13% |
| Hypertension |
12% |
13% |
19% |
4% |
| Nausea |
9% |
9% |
9% |
11% |
| Bradycardia |
5% |
5% |
3% |
0 |
| Atrial Fibrillation |
4% |
5% |
3% |
7% |
| Pyrexia |
4% |
4% |
4% |
4% |
| Dry Mouth |
4% |
3% |
1% |
1% |
| Vomiting |
3% |
3% |
5% |
3% |
| Hypovolemia |
3% |
3% |
2% |
5% |
| Atelectasis |
3% |
3% |
3% |
6% |
| Pleural Effusion |
2% |
2% |
1% |
6% |
| Agitation |
2% |
2% |
3% |
1% |
| Tachycardia |
2% |
2% |
4% |
1% |
| Anemia |
2% |
2% |
2% |
2% |
| Hyperthermia |
2% |
2% |
3% |
0 |
| Chills |
2% |
2% |
3% |
2% |
| Hyperglycemia |
2% |
2% |
2% |
3% |
| Hypoxia |
2% |
2% |
2% |
3% |
| Post-procedural Hemorrhage |
2% |
2% |
3% |
4% |
| Pulmonary Edema |
1% |
1% |
1% |
3% |
| Hypocalcemia |
1% |
1% |
0 |
2% |
| Acidosis |
1% |
1% |
1% |
2% |
| Urine Output Decreased |
1% |
1% |
0 |
2% |
| Sinus Tachycardia |
1% |
1% |
1% |
2% |
| Ventricular Tachycardia |
<1% |
1% |
1% |
5% |
| Wheezing |
<1% |
1% |
0 |
2% |
| Edema Peripheral |
<1% |
0 |
1% |
2% |
|
*26 subjects in the all dexmedetomidine injection group and 10 subjects in the randomized dexmedetomidine injection group had exposure for greater than 24 hours. |
||||
Table 3: Treatment-Emergent Adverse Events Occurring in >1% of All Dexmedetomidine-Treated Adult Patients in the Randomized Placebo-Controlled Continuous Infusion <24 Hours ICU Sedation Studies
|
Adverse Event |
Randomized Dexmedetomidine (N = 387)
|
Placebo
(N = 379) |
| Hypotension |
28% |
13% |
| Hypertension |
16% |
18% |
| Nausea |
11% |
9% |
| Bradycardia |
7% |
3% |
| Fever |
5% |
4% |
| Vomiting |
4% |
6% |
| Atrial Fibrillation |
4% |
3% |
| Hypoxia |
4% |
4% |
| Tachycardia |
3% |
5% |
| Hemorrhage |
3% |
4% |
| Anemia |
3% |
2% |
| Dry Mouth |
3% |
1% |
| Rigors |
2% |
3% |
| Agitation |
2% |
3% |
| Hyperpyrexia |
2% |
3% |
| Pain |
2% |
2% |
| Hyperglycemia |
2% |
2% |
| Acidosis |
2% |
2% |
| Pleural Effusion |
2% |
1% |
| Oliguria |
2% |
<1% |
| Thirst |
2% |
<1% |
Table 4: Key Treatment-Emergent Adverse Events Occurring in Dexmedetomidine- or Midazolam-Treated Adult Patients in the Randomized Active Comparator Continuous Infusion Long-Term Intensive Care Unit Sedation Study
|
Adverse Event
|
Dexmedetomidine
(N = 244) |
Midazolam
(N = 122) |
| Hypotension1
|
56% |
56% |
| Hypotension Requiring Intervention |
28% |
27% |
| Bradycardia2
|
42% |
19% |
| Bradycardia Requiring Intervention |
5% |
1% |
| Systolic Hypertension3
|
28% |
42% |
| Tachycardia4
|
25% |
44% |
| Tachycardia Requiring Intervention |
10% |
10% |
| Diastolic Hypertension3
|
12% |
15% |
| Hypertension3
|
11% |
15% |
| Hypertension Requiring Intervention† |
19% |
30% |
| Hypokalemia |
9% |
13% |
| Pyrexia |
7% |
2% |
| Agitation |
7% |
6% |
| Hyperglycemia |
7% |
2% |
| Constipation |
6% |
6% |
| Hypoglycemia |
5% |
6% |
| Respiratory Failure |
5% |
3% |
| Renal Failure Acute |
2% |
1% |
| Acute Respiratory Distress Syndrome |
2% |
1% |
| Generalized Edema |
2% |
6% |
| Hypomagnesemia |
1% |
7% |
|
† Includes any type of hypertension. 1 Hypotension was defined in absolute terms as Systolic blood pressure of <80 mmHg or Diastolic blood pressure of <50 mmHg or in relative terms as ≤30% lower than pre-study drug infusion value. 2 Bradycardia was defined in absolute terms as <40 bpm or in relative terms as ≤30% lower than pre-study drug infusion value. 3 Hypertension was defined in absolute terms as Systolic blood pressure >180 mmHg or Diastolic blood pressure of >100 mmHg or in relative terms as ≥30% higher than pre-study drug infusion value. 4 Tachycardia was defined in absolute terms as >120 bpm or in relative terms as ≥30% greater than pre-study drug infusion value. |
||
Table 5. Number (%) of Adult Subjects Who Had a Dose-Related Increase in Treatment Emergent Adverse Events by Maintenance Adjusted Dose Rate Range in the Dexmedetomidine Injection Group
|
Dexmedetomidine Injection mcg/kg/hr
|
|||
|
Adverse Event |
≤0.7*
(N = 95) |
>0.7 to ≤1.1*
(N = 78) |
>1.1*
(N = 71) |
| Constipation |
6% |
5% |
14% |
| Agitation |
5% |
8% |
14% |
| Anxiety |
5% |
5% |
9% |
| Edema Peripheral |
3% |
5% |
7% |
| Atrial Fibrillation |
2% |
4% |
9% |
| Respiratory Failure |
2% |
6% |
10% |
| Acute Respiratory Distress Syndrome |
1% |
3% |
9% |
| *Average maintenance dose over the entire study drug administration |
|||
Adverse reaction information is derived from the two trials for adult procedural sedation [see Clinical Studies (14.2)] in which 318 adult patients received dexmedetomidine. The mean total dose was 1.6 mcg/kg (range: 0.5 to 6.7), mean dose per hour was 1.3 mcg/kg/hr (range: 0.3 to 6.1) and the mean duration of infusion of 1.5 hours (range: 0.1 to 6.2). The population was between 18 to 93 years of age, ASA I-IV, 30% ≥ 65 years of age, 52% male and 61% Caucasian.
Treatment-emergent adverse reactions occurring in adults at an incidence of >2% are provided in Table 6. The most frequent adverse reactions were hypotension, bradycardia, and dry mouth [see Warnings and Precautions (5.2)]. Pre- specified criteria for the vital signs to be reported as adverse reactions are footnoted below the table. The decrease in respiratory rate and hypoxia was similar between dexmedetomidine injection and comparator groups in both studies.
Table 6: Adverse Reactions that Occurred with an Incidence of Greater than 2% and Greater in the Placebo Group in Clinical Trials of Dexmedetomidine Injection for Adult Procedural
|
Adverse Event |
Dexmedetomidine Injection
(N = 318) (%) |
Placebo
(N = 113) (%) |
| Hypotension1
|
54% |
30% |
| Respiratory Depression2
|
37% |
32% |
| Bradycardia3
|
14% |
4% |
| Hypertension4
|
13% |
24% |
| Tachycardia5
|
5% |
17% |
| Nausea |
3% |
2% |
| Dry Mouth |
3% |
1% |
| Hypoxia6
|
2% |
3% |
| Bradypnea |
2% |
4% |
|
1Hypotension was defined in absolute and relative terms as Systolic blood pressure of <80 mmHg or ≤30% lower than pre-study drug infusion value, or Diastolic blood pressure of <50 mmHg. 2 Respiratory depression was defined in absolute and relative terms as respiratory rate (RR) <8 beats per minute or >25% decrease from baseline. 3 Bradycardia was defined in absolute and relative terms as <40 beats per minute or ≤30% lower than pre-study drug infusion value. Subjects in Study 2 were pretreated with glycopyrrolate 0.1 mg intravenously before receiving study drug [see Clinical Studies (14.2)] . 4 Hypertension was defined in absolute and relative terms as Systolic blood pressure >180 mmHg or ≥30% higher than pre-study drug infusion value or Diastolic blood pressure of >100 mmHg. 5 Tachycardia was defined in absolute and relative terms as >120 beats per minute or ≥30% greater than pre-study drug infusion value. 6 Hypoxia was defined in absolute and relative terms as SpO2 <90% or 10% decrease from baseline. |
||
6.2 Postmarketing Experience
Hypotension and bradycardia were the most common adverse reactions associated with the use of dexmedetomidine injection during post approval use of the drug.
Table 7: Adverse Reactions Experienced During Post-Approval Use of Dexmedetomidine hydrochloride
|
System Organ Class
|
Preferred Term
|
| Blood and Lymphatic System Disorders |
Anemia |
| Cardiac Disorders |
Arrhythmia, atrial fibrillation, atrioventricular block, bradycardia, cardiac arrest, cardiac disorder, extrasystoles, myocardial infarction, supraventricular tachycardia, tachycardia, ventricular arrhythmia, ventricular tachycardia |
| Eye Disorders |
Photopsia, visual impairment |
| Gastrointestinal Disorders |
Abdominal pain, diarrhea, nausea, vomiting |
| General Disorders and Administration Site Conditions |
Chills, hyperpyrexia, pain, pyrexia, thirst |
| Hepatobiliary Disorders |
Hepatic function abnormal, hyperbilirubinemia |
| Investigations |
Alanine aminotransferase increased, aspartate aminotransferase increased, blood alkaline phosphatase increased, blood urea increased, electrocardiogram T wave inversion, gammaglutamyltransferase increased, electrocardiogram QT prolonged |
| Metabolism and Nutrition Disorders |
Acidosis, hyperkalemia, hypoglycemia, hypovolemia, hypernatremia |
| Nervous System Disorders |
Convulsion, dizziness, headache, neuralgia, neuritis, speech disorder |
| Psychiatric Disorders |
Agitation, confusional state, delirium, hallucination, illusion |
| Renal and Urinary Disorders |
Oliguria, polyuria |
| Respiratory, Thoracic and Mediastinal Disorders |
Apnea, bronchospasm, dyspnea, hypercapnia, hypoventilation, hypoxia, pulmonary congestion, respiratory acidosis |
| Skin and Subcutaneous Tissue Disorders |
Hyperhidrosis, pruritus, rash, urticaria |
| Surgical and Medical Procedures |
Light anesthesia |
| Vascular Disorders |
Blood pressure fluctuation, hemorrhage, hypertension, hypotension |
7 DRUG INTERACTIONS
7.1 Anesthetics, Sedatives, Hypnotics, Opioids
7.2 Neuromuscular Blockers
8 USE IN SPECIFIC POPULATIONS
8.1 Pregnancy
Available data from published randomized controlled trials and case reports over several decades of use with intravenously administered dexmedetomidine during pregnancy have not identified a drug-associated risk of major birth defects and miscarriage; however, the reported exposures occurred after the first trimester. Most of the available data are based on studies with exposures that occurred at the time of caesarean section delivery, and these studies have not identified an adverse effect on maternal outcomes or infant Apgar scores. Available data indicate that dexmedetomidine crosses the placenta.
In animal reproduction studies, fetal toxicity that lower fetal viability and reduced live fetuses occurred with subcutaneous administration of dexmedetomidine to pregnant rats during organogenesis at doses 1.8 times the maximum recommended human dose (MRHD) of 17.8 mcg/kg/day.
Developmental toxicity (low pup weights and adult offspring weights, decreased F1 grip strength, increased early implantation loss and decreased viability of second-generation offspring) occurred when pregnant rats were subcutaneously administered dexmedetomidine at doses less than the clinical dose from late pregnancy through lactation and weaning (see Data).
The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2-4% and 15- 20%, respectively.
Data
Animal Data
Increased post-implantation losses and reduced live fetuses in the presence of maternal toxicity (i.e. decreased body weight) were noted in a rat embryo-fetal development study in which pregnant dams were administered subcutaneous doses of dexmedetomidine 200 mcg/kg/day (equivalent to 1.8 times the intravenous MRHD of 17.8 mcg/kg/day based on body surface area [BSA]) during the period of organogenesis (Gestation Day [GD] 6 to 15). No malformations were reported.
No malformations or embryo-fetal toxicity were noted in a rabbit embryo-fetal development study in which pregnant does were administered dexmedetomidine intravenously at doses of up to 96 mcg/kg/day (approximately half the human exposure at the MRHD based on AUC) during the period of organogenesis (GD 6 to 18).
Reduced pup and adult offspring birth weights, and grip strength were reported in a rat developmental toxicology study in which pregnant females were administered dexmedetomidine subcutaneously at doses of 8 mcg/kg/day (0.07 times the MRHD based on BSA) during late pregnancy through lactation and weaning (GD 16 to postnatal day [PND] 25).
Decreased viability of second generation offspring and an increase in early implantation loss along with delayed motor development occurred in the 32 mcg/kg/day group (equivalent to less than the clinical dose based on BSA) when first generation offspring were allowed to mate. This study limited dosing to hard palate closure (GD 15 to 18) through weaning instead of dosing from implantation (GD 6 to 7) to weaning (PND 21).
In a study in the pregnant rat, placental transfer of dexmedetomidine was observed when radiolabeled dexmedetomidine was administered subcutaneously.
8.2 Lactation
Available published literature reports the presence of dexmedetomidine in human milk following intravenous administration (see Data). There is no information regarding the effects of dexmedetomidine on the breastfed infant or the effects on milk production. Advise women to monitor the breastfed infant for irritability. The developmental and health benefits of breastfeeding should be considered along with the mother's clinical need for dexmedetomidine and any potential adverse effects on the breastfed infant from dexmedetomidine or from the underlying condition.
Data
In two published clinical studies, a total of 14 women were given intravenous dexmedetomidine 6 mcg/kg/hour for 10 minutes after delivery followed by continuous infusion of 0.2–0.7 mcg/kg/hour. Breast milk and maternal blood samples were collected at 0, 6, 12, and 24 hours after discontinuation of dexmedetomidine. Plasma and milk dexmedetomidine concentrations were detectable up to 6 hours in most subjects, up to 12 hours in one subject and undetectable in all at 24 hours. The milk-to-plasma ratio from single paired maternal milk and plasma concentrations at each time point ranged from 0.53 to 0.95. The relative infant dose was estimated to range from 0.02 to 0.098%.
8.4 Pediatric Use
8.5 Geriatric Use
A total of 729 patients in the clinical studies were 65 years of age and over. A total of 200 patients were 75 years of age and over. In patients greater than 65 years of age, a higher incidence of bradycardia and hypotension was observed following administration of dexmedetomidine injection [see Warnings and Precautions (5.1, 5.2)]. Therefore a dose reduction may be considered in patients over 65 years of age [see Dosage and Administration (2.3) and Clinical Pharmacology (12.3)].
Procedural Sedation
A total of 131 patients in the clinical studies were 65 years of age and over. A total of 47 patients were 75 years of age and over. Hypotension occurred in a higher incidence in dexmedetomidine injection-treated patients 65 years or older (72%) and 75 years or older (74%) as compared to patients <65 years (47%). A reduced loading dose of 0.5 mcg/kg given over 10 minutes is recommended and a reduction in the maintenance infusion should be considered for patients greater than 65 years of age.
8.6 Hepatic Impairment
9 DRUG ABUSE AND DEPENDENCE
9.1 Controlled Substance
9.3 Dependence
10 OVERDOSAGE
Five adult patients received an overdose of dexmedetomidine in the intensive care unit sedation studies. Two of these patients had no symptoms reported; one patient received a 2 mcg/kg loading dose over 10 minutes (twice the recommended loading dose) and one patient received a maintenance infusion of 0.8 mcg/kg/hr. Two other patients who received a 2 mcg/kg loading dose over 10 minutes, experienced bradycardia and/or hypotension. One patient who received a loading bolus dose of undiluted dexmedetomidine (19.4 mcg/kg), had cardiac arrest from which he was successfully resuscitated.
11 DESCRIPTION
Dexmedetomidine hydrochloride is a central alpha-2 adrenergic agonist. Structurally it is the S-enantiomer of medetomidine and is chemically described as 4-[(S)-α,2,3-Trimethylbenzyl]imidazole monohydrochloride.
Dexmedetomidine hydrochloride is a white or almost white crystalline powder that is freely soluble in water and has a pKa of 7.1. Its partition coefficient in-octanol: water at pH 7.4 is 2.89.
Dexmedetomidine Injection is supplied as a clear, colorless, isotonic solution with a pH of 4.5 to 7. Each mL contains 118 mcg of dexmedetomidine hydrochloride USP, equivalent to 100 mcg (0.1 mg) of dexmedetomidine, 1.6 mg of methylparaben NF and 0.2 mg of propylparaben NF, as preservatives and 9 mg of sodium chloride USP, as tonicity agent in water for injection.
12 CLINICAL PHARMACOLOGY
12.1 Mechanism of Action
12.2 Pharmacodynamics
12.3 Pharmacokinetics
Dexmedetomidine exhibits linear pharmacokinetics in the dosage range of 0.2 to 0.7 mcg/kg/hr when administered to adults by intravenous infusion for up to 24 hours. Table 8 shows the main pharmacokinetic parameters when dexmedetomidine injection was infused (after appropriate loading doses) at maintenance infusion rates of 0.17 mcg/kg/hr (target plasma concentration of 0.3 ng/mL) for 12 and 24 hours, 0.33 mcg/kg/hr (target plasma concentration of 0.6 ng/mL) for 24 hours, and 0.70 mcg/kg/hr (target plasma concentration of 1.25 ng/mL) for 24 hours.
Table 8: Mean ± SD Pharmacokinetic Parameters in Adults
|
Parameter |
Loading Infusion (min)/Total Infusion Duration (hrs)
|
|||
|
10 min/12 hrs
|
10 min/24 hrs
|
10 min/24 hrs
|
35 min/24 hrs
|
|
|
Dexmedetomidine Target Plasma Concentration (ng/mL) and Dose (mcg/kg/hr)
|
||||
|
0.3/0.17
|
0.3/0.17
|
0.6/0.33
|
1.25/0.70
|
|
|
t1/2*, hour
|
1.78 ± 0.30 |
2.22 ± 0.59 |
2.23 ± 0.21 |
2.50 ± 0.61 |
|
CL, liter/hour
|
46.3 ± 8.3 |
43.1 ± 6.5 |
35.3 ± 6.8 |
36.5 ± 7.5 |
|
Vss, liter
|
88.7 ± 22.9 |
102.4 ± 20.3 |
93.6 ± 17.0 |
99.6 ± 17.8 |
|
Avg Css #, ng/mL
|
0.27 ± 0.05 |
0.27 ± 0.05 |
0.67 ± 0.10 |
1.37 ± 0.20 |
| Abbreviations: t1/2 = half-life, CL = clearance, Vss = steady-state volume of distribution. * Presented as harmonic mean and pseudo standard deviation. # Mean Css = Average steady-state concentration of dexmedetomidine. The mean Css was calculated based on post- dose sampling from 2.5 to 9 hours samples for 12 hour infusion and post-dose sampling from 2.5 to 18 hours for 24 hour infusions. The loading doses for each of the above indicated groups were 0.5, 0.5, 1 and 2.2 mcg/kg, respectively. |
||||
Distribution
The steady-state volume of distribution (Vss) of dexmedetomidine was approximately 118 liters. Dexmedetomidine protein binding was assessed in the plasma of normal healthy male and female subjects. The average protein binding was 94% and was constant across the different plasma concentrations tested. Protein binding was similar in males and females. The fraction of dexmedetomidine that was bound to plasma proteins was significantly decreased in subjects with hepatic impairment compared to healthy subjects.
The potential for protein binding displacement of dexmedetomidine by fentanyl, ketorolac, theophylline, digoxin and lidocaine was explored in vitro, and negligible changes in the plasma protein binding of dexmedetomidine were observed. The potential for protein binding displacement of phenytoin, warfarin, ibuprofen, propranolol, theophylline and digoxin by dexmedetomidine was explored in vitro and none of these compounds appeared to be significantly displaced by dexmedetomidine.
Elimination
Metabolism
Dexmedetomidine undergoes almost complete biotransformation with very little unchanged dexmedetomidine excreted in urine and feces. Biotransformation involves both direct glucuronidation as well as cytochrome P450 mediated metabolism. The major metabolic pathways of dexmedetomidine are: direct N-glucuronidation to inactive metabolites; aliphatic hydroxylation (mediated primarily by CYP2A6 with a minor role of CYP1A2, CYP2E1, CYP2D6 and CYP2C19) of dexmedetomidine to generate 3-hydroxy-dexmedetomidine, the glucuronide of 3-hydroxy- dexmedetomidine, and 3-carboxy-dexmedetomidine; and N-methylation of dexmedetomidine to generate 3-hydroxy N- methyl-dexmedetomidine, 3-carboxy N-methyl-dexmedetomidine, and dexmedetomidine-N-methyl O-glucuronide.
Excretion
The terminal elimination half-life (t1/2) of dexmedetomidine is approximately 2 hours and clearance is estimated to be approximately 39 L/h. A mass balance study demonstrated that after nine days an average of 95% of the radioactivity, following intravenous administration of radiolabeled dexmedetomidine, was recovered in the urine and 4% in the feces. No unchanged dexmedetomidine was detected in the urine. Approximately 85% of the radioactivity recovered in the urine was excreted within 24 hours after the infusion. Fractionation of the radioactivity excreted in urine demonstrated that products of N-glucuronidation accounted for approximately 34% of the cumulative urinary excretion. In addition, aliphatic hydroxylation of parent drug to form 3-hydroxy-dexmedetomidine, the glucuronide of 3-hydroxy- dexmedetomidine, and 3-carboxylic acid-dexmedetomidine together represented approximately 14% of the dose in urine. N-methylation of dexmedetomidine to form 3-hydroxy N-methyl dexmedetomidine, 3-carboxy N-methyl dexmedetomidine, and N-methyl O-glucuronide dexmedetomidine accounted for approximately 18% of the dose in urine. The N-Methyl metabolite itself was a minor circulating component and was undetected in urine. Approximately 28% of the urinary metabolites have not been identified.
Specific Populations
Male and Female Patients
There was no observed difference in dexmedetomidine pharmacokinetics due to sex.
Geriatric Patients
The pharmacokinetic profile of dexmedetomidine injection was not altered by age. There were no differences in the pharmacokinetics of dexmedetomidine injection in young (18–40 years), middle age (41–65 years), and elderly (>65 years) subjects.
Patients with Hepatic Impairment
In adult subjects with varying degrees of hepatic impairment (Child-Pugh Class A, B, or C), clearance values for dexmedetomidine were lower than in healthy subjects. The mean clearance values for patients with mild, moderate, and severe hepatic impairment were 74%, 64% and 53% of those observed in the normal healthy adult subjects, respectively. Mean clearances for free drug were 59%, 51% and 32% of those observed in the normal healthy adult subjects, respectively.
Although dexmedetomidine is dosed to effect, it may be necessary to consider dose reduction in subjects with hepatic impairment [see Dosage and Administration (2.2), Warnings and Precautions (5.8)].
Patients with Renal Impairment
Dexmedetomidine pharmacokinetics (Cmax, Tmax, AUC, t1/2, CL, and Vss) were not significantly different in patients with severe renal impairment (creatinine clearance: <30 mL/min) compared to healthy subjects.
Drug Interaction Studies
In Vitro Studies: In vitro studies in human liver microsomes demonstrated no evidence of cytochrome P450 mediated drug interactions that are likely to be of clinical relevance.
13 NONCLINICAL TOXICOLOGY
13.1 Carcinogenesis, Mutagenesis, Impairment of Fertility
Animal carcinogenicity studies have not been performed with dexmedetomidine.
Mutagenesis
Dexmedetomidine was not mutagenic in vitro, in either the bacterial reverse mutation assay (E. coli and Salmonella typhimurium) or the mammalian cell forward mutation assay (mouse lymphoma). Dexmedetomidine was clastogenic in the in vitro human lymphocyte chromosome aberration test with, but not without, rat S9 metabolic activation. In contrast, dexmedetomidine was not clastogenic in the in vitro human lymphocyte chromosome aberration test with or without human S9 metabolic activation. Although dexmedetomidine was clastogenic in an in vivo mouse micronucleus test in NMRI mice, there was no evidence of clastogenicity in CD-1 mice.
Impairment of Fertility
Fertility in male or female rats was not affected after daily subcutaneous injections of dexmedetomidine at doses up to 54 mcg/kg (less than the maximum recommended human intravenous dose on a mcg/m2 basis) administered from 10 weeks prior to mating in males, and 3 weeks prior to mating and during mating in females.
13.2 Animal Pharmacology and/or Toxicology
14 CLINICAL STUDIES
14.1 Intensive Care Unit Sedation
Table 9: Ramsay Level of Sedation Scale
|
Clinical Score
|
Level of Sedation Achieved
|
| 6 |
Asleep, no response |
| 5 |
Asleep, sluggish response to light glabellar tap or loud auditory stimulus |
| 4 |
Asleep, but with brisk response to light glabellar tap or loud auditory stimulus |
| 3 |
Patient responds to commands |
| 2 |
Patient cooperative, oriented, and tranquil |
| 1 |
Patient anxious, agitated, or restless |
A second prospective primary analysis assessed the sedative effects of dexmedetomidine injection by comparing the percentage of adult patients who achieved a Ramsay sedation score of ≥3 during intubation without the use of additional rescue medication. A significantly greater percentage of adult patients in the dexmedetomidine injection group maintained a Ramsay sedation score of ≥3 without receiving any midazolam rescue compared to the placebo group (see Table 10).
Table 10: Midazolam Use as Rescue Medication During Intubation (ITT) Study One
|
Placebo
(N = 175) |
Dexmedetomidine Injection
(N = 178) |
p-value |
|
|
Mean Total Dose (mg) of Midazolam
|
19 mg |
5 mg |
0.0011* |
| Standard deviation |
53 mg |
19 mg |
|
|
Categorized Midazolam Use
|
|||
| 0 mg |
43 (25%) |
108 (61%) |
<0.001** |
| 0–4 mg |
34 (19%) |
36 (20%) |
|
| >4 mg |
98 (56%) |
34 (19%) |
|
| ITT (intent-to-treat) population includes all randomized patients. * ANOVA model with treatment center. ** Chi-square. |
|||
In a second study, 198 adult patients were randomized to receive placebo and 203 to receive dexmedetomidine injection by intravenous infusion at a dose of 0.4 mcg/kg/hr (with allowed adjustment between 0.2 and 0.7 mcg/kg/hr) following an initial loading infusion of one mcg/kg intravenous over 10 minutes. The study drug infusion was adjusted to maintain a Ramsay sedation score of ≥3. Patients were allowed to receive "rescue" propofol as needed to augment the study drug infusion. In addition, morphine sulfate was administered as needed for pain. The primary outcome measure for this study was the total amount of rescue medication (propofol) needed to maintain sedation as specified while intubated.
Adult patients randomized to placebo received significantly more propofol than adult patients randomized to dexmedetomidine injection (see Table 11).
A significantly greater percentage of adult patients in the dexmedetomidine injection group compared to the placebo group maintained a Ramsay sedation score of ≥3 without receiving any propofol rescue (see Table 11).
Table 11: Propofol Use as Rescue Medication During Intubation (ITT) Study Two
|
Placebo
(N = 198) |
Dexmedetomidine Injection
(N = 203) |
p-value |
|
|
Mean Total Dose (mg) of Propofol
|
513 mg |
72 mg |
<0.0001*
|
| Standard deviation |
782 mg |
249 mg |
|
|
Categorized Propofol Use
|
|||
| 0 mg |
47 (24%) |
122 (60%) |
<0.001** |
| 0–50 mg |
30 (15%) |
43 (21%) |
|
| >50 mg |
121 (61%) |
38 (19%) |
|
|
* ANOVA model with treatment center. ** Chi-square. |
|||
In a controlled clinical trial, dexmedetomidine injection was compared to midazolam for ICU sedation exceeding 24 hours duration. Dexmedetomidine injection was not shown to be superior to midazolam for the primary efficacy endpoint, the percent of time patients were adequately sedated (81% versus 81%). In addition, administration of dexmedetomidine injection for longer than 24 hours was associated with tolerance, tachyphylaxis, and a dose-related increase in adverse events [see Adverse Reactions (6.1)].
14.2 Procedural Sedation
The safety and efficacy of dexmedetomidine injection for sedation of non-intubated adult patients prior to and/or during surgical and other procedures was evaluated in two randomized, double-blind, placebo-controlled multicenter clinical trials. Study 1 evaluated the sedative properties of dexmedetomidine injection in adult patients having a variety of elective surgeries/procedures performed under monitored anesthesia care. Study 2 evaluated dexmedetomidine injection in adult patients undergoing awake fiberoptic intubation prior to a surgical or diagnostic procedure.
In Study 1, the sedative properties of dexmedetomidine injection were evaluated by comparing the percent of adult patients not requiring rescue midazolam to achieve a specified level of sedation using the standardized Observer's Assessment of Alertness/Sedation Scale (see Table 12).
Table 12: Observer's Assessment of Alertness/Sedation
|
Assessment Categories
|
||||
|
Responsiveness
|
Speech
|
Facial Expression
|
Eyes
|
Composite Score
|
| Responds readily to name spoken in normal tone |
Normal |
Normal |
Clear, no ptosis |
5 (alert) |
| Lethargic response to name spoken in normal tone |
Mild slowing or thickening |
Mild relaxation |
Glazed or mild ptosis (less than half the eye) |
4 |
| Responds only after name is called loudly and/or repeatedly |
Slurring or prominent slowing |
Marked relaxation (slack jaw) |
Glazed and marked ptosis (half the eye or more) |
3 |
| Responds only after mild prodding or shaking |
Few recognizable words |
– |
– |
2 |
| Does not respond to mild prodding or shaking |
– |
– |
– |
1 (deep sleep) |
Efficacy results showed that dexmedetomidine was more effective than the comparator group when used to sedate non-intubated patients requiring monitored anesthesia care during surgical and other procedures (see Table 13).
In Study 2, the sedative properties of dexmedetomidine were evaluated by comparing the percent of adult patients requiring rescue midazolam to achieve or maintain a specified level of sedation using the Ramsay Sedation Scale score ≥2 (see Table 9). Adult patients were randomized to receive a loading infusion of dexmedetomidine 1 mcg/kg or placebo (normal saline) given over 10 minutes and followed by a fixed maintenance infusion of 0.7 mcg/kg/hr. After achieving the desired level of sedation, topicalization of the airway occurred. Adult patients were allowed to receive rescue midazolam as needed to achieve and/or maintain a Ramsay Sedation Scale ≥2.
Demographic characteristics were similar between the dexmedetomidine and comparator groups. For efficacy results see Table 13.
Table 13: Key Efficacy Results of Adult Procedural Sedation Studies
|
Study |
Loading Infusion
Treatment Arm |
Number
of Patients Enrolleda |
% Not
Requiring Midazolam Rescue |
Confidenceb
Interval on the Difference vs. Placebo |
Mean (SD)
Total Dose (mg) of Rescue Midazolam Required |
Confidenceb Intervals of the Mean Rescue Dose |
|
Study 1
|
Dexmedetomidine 0.5 mcg/kg |
134 |
40 |
37 (27, 48) |
1.4 (1.7) |
-2.7 (-3.4, -2.0) |
| Dexmedetomidine 1 mcg/kg |
129 |
54 |
51 (40, 62) |
0.9 (1.5) |
-3.1 (-3.8, -2.5) |
|
| Placebo |
63 |
3 |
– |
4.1 (3.0) |
– |
|
|
Study 2
|
Dexmedetomidine 1 mcg/kg |
55 |
53 |
39 (20, 57) |
1.1 (1.5) |
-1.8 (-2.7, -0.9) |
| Placebo |
50 |
14 |
– |
2.9 (3.0) |
– |
b Normal approximation to the binomial with continuity correction
16 HOW SUPPLIED/STORAGE AND HANDLING
|
NDC No.
|
Strength
|
Package
|
| 700069- 758 -04 |
400 mcg/4 mL (100 mcg/mL) |
4 vials/carton |
| 700069- 759 -04 |
1000 mcg/10 mL(100 mcg/mL) |
4 vials/carton |
17 PATIENT COUNSELING INFORMATION
- When dexmedetomidine is infused for more than 6 hours, patients should be informed to report nervousness, agitation, and headaches that may occur for up to 48 hours.
- Additionally, patients should be informed to report symptoms that may occur within 48 hours after the administration of dexmedetomidine injection such as: weakness, confusion, excessive sweating, weight loss, abdominal pain, salt cravings, diarrhea, constipation, dizziness or light-headedness.
- Advise breastfeeding mothers who were exposed to dexmedetomidine to monitor breastfed neonates for irritability [see Use in Specific Populations (8.2)].
SPL UNCLASSIFIED
Somerset Therapeutics, LLC
Somerset, NJ 08873
Customer Care # 1-800-417-9175
Made in India
Code No.:KR/DRUGS/KTK/28/289/97
1200980
ST-DMH/P/01
PACKAGE LABEL.PRINCIPAL DISPLAY PANEL
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