^ Pharmacodynamics
In a study in healthy adult volunteers (N = 10), respiratory rate and oxygen saturation remained within normal limits and there was no evidence of respiratory depression when dexmedetomidine was administered by intravenous infusion at doses within the recommended dose range (0.2 to 0.70 mcg/kg/hr).
^ Administration Instructions
^ Patient Counseling Information
Dexmedetomidine hydrochloride in 0.9% sodium chloride injection is indicated for short-term intravenous sedation. Dosage must be individualized and titrated to the desired clinical effect. Blood pressure, heart rate and oxygen levels will be monitored both continuously during the infusion of dexmedetomidine hydrochloride in 0.9% sodium chloride injection and as clinically appropriate after discontinuation.
SAGENT® Mfd. for SAGENT PharmaceuticalsSchaumburg, IL 60195 (USA)Made in Italy©2023 Sagent Pharmaceuticals
October 2023
SAGENT Pharmaceuticals®
^ Description
Dexmedetomidine hydrochloride in 0.9% sodium chloride injection (4 mcg per mL) is a sterile, nonpyrogenic ready to use solution suitable for intravenous infusion.
Dexmedetomidine hydrochloride in 0.9% sodium chloride injection contains dexmedetomidine hydrochloride as the active pharmaceutical ingredient. Dexmedetomidine hydrochloride is a central alpha2-adrenergic agonist. Dexmedetomidine hydrochloride is the S-enantiomer of medetomidine. Dexmedetomidine hydrochloride chemical name is 1H-Imidazole, 4-[1-(2,3-dimethylphenyl)ethyl]-, monohydrochloride, (S). Dexmedetomidine hydrochloride has a molecular weight of 236.7 and the empirical formula is C13H16N2 • HCl and the structural formula is:
Dexmedetomidine hydrochloride is a white or almost white 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 hydrochloride in 0.9% sodium chloride injection is ready to be used. It is supplied as a clear, colorless, isotonic solution with a pH between 4.5 to 7.0. Each mL contains 4.72 mcg of dexmedetomidine hydrochloride (equivalent to 4 mcg or 0.004 mg of dexmedetomidine) and 9 mg of sodium chloride in water for injection. The solution is preservative-free and contains no additives or chemical stabilizers.
^ Clinical Trials Experience
Because clinical trials are conducted under widely varying conditions, adverse reactions 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.
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.
^ Hyperthermia Or Pyrexia
Dexmedetomidine may induce hyperthermia or pyrexia, which may be resistant to traditional cooling methods, such as administration of cooled intravenous fluids and antipyretic medications. Discontinue dexmedetomidine if drug-related hyperthermia or pyrexia is suspected and monitor patients until body temperature normalizes.
^ Anesthetics, Sedatives, Hypnotics, Opioids
Co-administration of dexmedetomidine with anesthetics, sedatives, hypnotics, and opioids is likely to lead to an enhancement of effects. Specific studies have confirmed these effects with sevoflurane, isoflurane, propofol, alfentanil, and midazolam. No pharmacokinetic interactions between dexmedetomidine and isoflurane, propofol, alfentanil and midazolam have been demonstrated. However, due to possible pharmacodynamic interactions, when co-administered with dexmedetomidine, a reduction in dosage of dexmedetomidine or the concomitant anesthetic, sedative, hypnotic or opioid may be required.
^ Overdosage
The tolerability of dexmedetomidine was studied in one study in which healthy adult subjects were administered doses at and above the recommended dose of 0.2 to 0.7 mcg/kg/hr. The maximum blood concentration achieved in this study was approximately 13 times the upper boundary of the therapeutic range. The most notable effects observed in two subjects who achieved the highest doses were first degree atrioventricular block and second degree heart block. No hemodynamic compromise was noted with the atrioventricular block and the heart block resolved spontaneously within one minute.
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.
^ Drug Administration
Dexmedetomidine should be administered only by persons skilled in the management of patients in the intensive care or operating room setting. Due to the known pharmacological effects of dexmedetomidine, patients should be continuously monitored while receiving dexmedetomidine.
^ Dependence
The dependence potential of dexmedetomidine has not been studied in humans. However, since studies in rodents and primates have demonstrated that dexmedetomidine exhibits pharmacologic actions similar to those of clonidine, it is possible that dexmedetomidine may produce a clonidine-like withdrawal syndrome upon abrupt discontinuation [see Warnings and Precautions (5.5)].
^ Hepatic Impairment
Since dexmedetomidine clearance decreases with increasing severity of hepatic impairment, dose reduction should be considered in patients with impaired hepatic function [see Dosage and Administration (2.2, 2.3), Clinical Pharmacology (12.3)].
^3 Dosage Forms And Strengths
Dexmedetomidine hydrochloride in 0.9% sodium chloride injection is a clear and colorless solution, ready to use. It is available as:
^ Compatibility With Natural Rubber
Compatibility studies have demonstrated the potential for absorption of dexmedetomidine hydrochloride in 0.9% sodium chloride injection to some types of natural rubber. Although dexmedetomidine hydrochloride in 0.9% sodium chloride injection is dosed to effect, it is advisable to use administration components made with synthetic or coated natural rubber gaskets.
^4 Contraindications
None.
^ Postmarketing Experience
The following adverse reactions have been identified during post-approval use of dexmedetomidine. 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.
Hypotension and bradycardia were the most common adverse reactions associated with the use of dexmedetomidine during post-approval use of the drug.
^ Animal Toxicology And/or Pharmacology
There were no differences in the adrenocorticotropic hormone (ACTH)-stimulated cortisol response in dogs following a single dose of dexmedetomidine compared to saline control. However, after continuous subcutaneous infusions of dexmedetomidine at 3 mcg/kg/hr and 10 mcg/kg/hr for one week in dogs (exposures estimated to be within the clinical range), the ACTH-stimulated cortisol response was diminished by approximately 27% and 40%, respectively, compared to saline-treated control animals indicating a dose-dependent adrenal suppression.
^ How Supplied/storage And Handling
Dexmedetomidine Hydrochloride in 0.9% Sodium Chloride Injection is supplied as follows:
Dexmedetomidine hydrochloride in 0.9% sodium chloride injection is clear and colorless. The strengths are based on the dexmedetomidine base. Discard unused portion.
Do not use if product is discolored or if precipitate matter is present.
^ Intensive Care Unit Sedation
Two randomized, double-blind, parallel-group, placebo-controlled multicenter clinical trials included 754 adult patients being treated in a surgical intensive care unit. All patients were initially intubated and received mechanical ventilation. These trials evaluated the sedative properties of dexmedetomidine by comparing the amount of rescue medication (midazolam in one trial and propofol in the second) required to achieve a specified level of sedation (using the standardized Ramsay Sedation Scale) between dexmedetomidine and placebo from onset of treatment to extubation or to a total treatment duration of 24 hours. The Ramsay Level of Sedation Scale is displayed in Table 12.
In the first study, 175 adult patients were randomized to receive placebo and 178 to receive dexmedetomidine 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 rate was adjusted to maintain a Ramsay sedation score of ≥3. Patients were allowed to receive “rescue” midazolam as needed to augment the study drug infusion. In addition, morphine sulfate was administered for pain as needed. The primary outcome measure for this study was the total amount of rescue medication (midazolam) needed to maintain sedation as specified while intubated. Patients randomized to placebo received significantly more midazolam than patients randomized to dexmedetomidine (see Table 13).
A second prospective primary analysis assessed the sedative effects of dexmedetomidine 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 group maintained a Ramsay sedation score of ≥3 without receiving any midazolam rescue compared to the placebo group (see Table 13).
A prospective secondary analysis assessed the dose of morphine sulfate administered to adult patients in the dexmedetomidine and placebo groups. On average, dexmedetomidine-treated patients received less morphine sulfate for pain than placebo-treated patients (0.47 versus 0.83 mg/h). In addition, 44% (79 of 178 patients) of dexmedetomidine patients received no morphine sulfate for pain versus 19% (33 of 175 patients) in the placebo group.
In a second study, 198 adult patients were randomized to receive placebo and 203 to receive dexmedetomidine 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 (see Table 14).
A significantly greater percentage of adult patients in the dexmedetomidine group compared to the placebo group maintained a Ramsay sedation score of ≥3 without receiving any propofol rescue (see Table 14).
A prospective secondary analysis assessed the dose of morphine sulfate administered to adult patients in the dexmedetomidine and placebo groups. On average, dexmedetomidine-treated patients received less morphine sulfate for pain than placebo-treated patients (0.43 versus 0.89 mg/h). In addition, 41% (83 of 203 patients) of dexmedetomidine patients received no morphine sulfate for pain versus 15% (30 of 198 patients) in the placebo group.
In a controlled clinical trial, dexmedetomidine was compared to midazolam for ICU sedation exceeding 24 hours duration. Dexmedetomidine 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 for longer than 24 hours was associated with tolerance, tachyphylaxis, and a dose-related increase in adverse events [see Adverse Reactions (6.1)].
^ Administration With Other Fluids
Dexmedetomidine hydrochloride in 0.9% sodium chloride injection infusion should not be co-administered through the same intravenous catheter with blood or plasma because physical compatibility has not been established.
Dexmedetomidine hydrochloride in 0.9% sodium chloride injection has been shown to be incompatible when administered with the following drugs: amphotericin B, diazepam.
Dexmedetomidine hydrochloride in 0.9% sodium chloride injection has been shown to be compatible when administered with the following intravenous fluids:
^ Dosage Adjustment
Due to possible pharmacodynamic interactions, a reduction in dosage of dexmedetomidine hydrochloride in 0.9% sodium chloride injection or other concomitant anesthetics, sedatives, hypnotics or opioids may be required when co-administered [see Drug Interactions (7.1)].
Dosage reductions may need to be considered for adult patients with hepatic impairment, and geriatric patients [see Warnings and Precautions (5.8), Use in Specific Populations (8.6), Clinical Pharmacology (12.3)].
^ Transient Hypertension
Transient hypertension has been observed primarily during the loading dose in association with the initial peripheral vasoconstrictive effects of dexmedetomidine. Treatment of the transient hypertension has generally not been necessary, although reduction of the loading infusion rate may be desirable.
^ Tolerance And Tachyphylaxis
Use of dexmedetomidine beyond 24 hours has been associated with tolerance and tachyphylaxis and a dose-related increase in adverse reactions [see Adverse Reactions (6.1)].
^ Procedural Sedation
Dexmedetomidine hydrochloride in 0.9% sodium chloride injection is indicated for sedation of non-intubated adult patients prior to and/or during surgical and other procedures.
Pediatric use information is approved for Hospira Inc.'s PRECEDEX TM (dexmedetomidine hydrochloride) injection and PRECEDEX TM (dexmedetomidine hydrochloride) in sodium chloride injection. However, due to Hospira Inc.'s marketing exclusivity rights, this drug product is not labeled with that information.
^ Arousability
Some patients receiving dexmedetomidine have been observed to be arousable and alert when stimulated. This alone should not be considered as evidence of lack of efficacy in the absence of other clinical signs and symptoms.
^ Clinical Studies
The safety and efficacy of dexmedetomidine has been evaluated in four randomized, double-blind, placebo-controlled multicenter clinical trials in 1,185 adult patients.
^ Intensive Care Unit Sedation
Dexmedetomidine hydrochloride in 0.9% sodium chloride injection is indicated for sedation of initially intubated and mechanically ventilated adult patients during treatment in an intensive care setting. Dexmedetomidine hydrochloride in 0.9% sodium chloride injection should be administered by continuous infusion not to exceed 24 hours.
Dexmedetomidine hydrochloride in 0.9% sodium chloride 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 hydrochloride in 0.9% sodium chloride injection prior to extubation.
^ Recommended Dosage
Pediatric use information is approved for Hospira Inc.'s PRECEDEX TM (dexmedetomidine hydrochloride) injection and PRECEDEX TM (dexmedetomidine hydrochloride) in sodium chloride injection. However, due to Hospira Inc.'s marketing exclusivity rights, this drug product is not labeled with that information.
^6 Adverse Reactions
The following clinically significant adverse reactions are described elsewhere in the labeling:
^ Controlled Substance
Dexmedetomidine hydrochloride is not a controlled substance.
^ Pharmacokinetics
Following intravenous administration to adults, dexmedetomidine exhibits the following pharmacokinetic parameters: a rapid distribution phase with a distribution half-life (t1/2) of approximately 6 minutes; a terminal elimination half-life (t1/2) of approximately 2 hours; and steady-state volume of distribution (Vss) of approximately 118 liters. Clearance is estimated to be approximately 39 L/h. The mean body weight associated with this clearance estimate was 72 kg.
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 10 shows the main pharmacokinetic parameters when dexmedetomidine 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 0.7 mcg/kg/hr (target plasma concentration of 1.25 ng/mL) for 24 hours.
The loading doses for each of the above indicated groups were 0.5, 0.5, 1 and 2.2 mcg/kg, respectively.
Dexmedetomidine pharmacokinetic parameters in adults after dexmedetomidine maintenance doses of 0.2 to 1.4 mcg/kg/hr for >24 hours were similar to the pharmacokinetic (PK) parameters after dexmedetomidine maintenance dosing for <24 hours in other studies. The values for clearance (CL), volume of distribution (V), and t1/2 were 39.4 L/hr, 152 L, and 2.67 hours, respectively.
^ Preparation Of Solution
Strict aseptic technique must always be maintained during handling of dexmedetomidine hydrochloride in 0.9% sodium chloride injection.
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.
^ Hepatic Impairment
Since dexmedetomidine clearance decreases with severity of hepatic impairment, dose reduction should be considered in patients with impaired hepatic function [see Dosage and Administration (2.2, 2.3)].
^ Neuromuscular Blockers
In one study of 10 healthy adult volunteers, administration of dexmedetomidine for 45 minutes at a plasma concentration of one ng/mL resulted in no clinically meaningful increases in the magnitude of neuromuscular blockade associated with rocuronium administration.
^ Mechanism Of Action
Dexmedetomidine is a relatively selective centrally acting alpha2-adrenergic agonist with sedative properties. Alpha2 selectivity is observed in animals following slow intravenous infusion of low and medium doses (10 to 300 mcg/kg). Both alpha1 and alpha2 activity is observed following slow intravenous infusion of high doses (≥1,000 mcg/kg) or with rapid intravenous administration.
^ Hypotension, Bradycardia, And Sinus Arrest
Clinically significant episodes of bradycardia and sinus arrest have been reported with dexmedetomidine administration in young, healthy adult volunteers with high vagal tone or with different routes of administration including rapid intravenous or bolus administration.
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.