Components:
Method of action:
Treatment option:
Medically reviewed by Kovalenko Svetlana Olegovna, PharmD. Last updated on 01.04.2022
Attention! Information on this page is intended only for medical professionals! Information is collected in open sources and may contain significant errors! Be careful and double-check all the information on this page!
Dosage Forms And Strengths
Precedex Injection
Precedex Injection, 200 mcg/2 mL dexmedetomidine (100 mcg/mL) in a glass vial. To be used after dilution.
Precedex In 0.9% Sodium Chloride Injection
Precedex Injection, 80 mcg dexmedetomidine/20 mL (4 mcg/mL) dexmedetomidine in a 20 mL glass vial. Ready to use.
Precedex Injection, 200 mcg dexmedetomidine/50 mL (4 mcg/mL) dexmedetomidine in a 50 mL glass bottle. Ready to use.
Precedex Injection, 400 mcg dexmedetomidine/100 mL (4 mcg/mL) dexmedetomidine in a 100 mL glass bottle. Ready to use.
Storage And Handling
Precedex Injection
Precedex (dexmedetomidine hydrochloride) injection 200 mcg/2 mL (100 mcg/mL) is available in 2 mL clear glass vials. The strength is based on the dexmedetomidine base. Vials are intended for single use only.
| NDC No. | Container | Size |
| 0409-1638-02 | Vial | 2 mL |
Precedex In 0.9% Sodium Chloride Injection
Precedex (dexmedetomidine hydrochloride in 0.9% Sodium Chloride) injection is available as 80 mcg/20 mL (4 mcg/mL), 200 mcg/50 mL (4 mcg/mL) and 400 mcg/100 mL (4 mcg/mL) in 20 mL clear glass vials, 50 mL and 100 mL clear glass bottles, respectively. Containers are intended for single use only.
| NDC No. | Container | Size |
| 0409-1660-20 | Vial | 20 mL |
| 0409-1660-50 | Bottle | 50 mL |
| 0409-1660-10 | Bottle | 100 mL |
Store at controlled room temperature, 25°C (77°F) with excursions allowed from 15 to 30°C (59 to 86°F).
Manufactured and Distributed by: Hospira, Inc. Lake Forest, IL 60045 USA. Revised: May 2016
Intensive Care Unit Sedation
Precedex™ is indicated for sedation of initially intubated and mechanically ventilated patients during treatment in an intensive care setting. Precedex should be administered by continuous infusion not to exceed 24 hours.
Precedex has been continuously infused in mechanically ventilated patients prior to extubation, during extubation, and post-extubation. It is not necessary to discontinue Precedex prior to extubation.
Procedural Sedation
Precedex is indicated for sedation of non-intubated patients prior to and/or during surgical and other procedures.
Dosing Guidelines
- Precedex dosing should be individualized and titrated to desired clinical response.
- Precedex is not indicated for infusions lasting longer than 24 hours.
- Precedex should be administered using a controlled infusion device.
Dosage Information
Table 1: Dosage Information
| 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: a dose reduction should be considered. For adult patients with impaired hepatic-function: a dose reduction should be considered. |
| 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: a dose reduction should be considered. For adult patients with impaired hepatic function: a dose reduction should be considered |
| 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. For adult patients with impaired hepatic function: a dose reduction should be considered. |
| 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. The rate of the maintenance infusion should be adjusted 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: a dose reduction should be considered. For adult patients with impaired hepatic function: a dose reduction should be considered. |
Dosage Adjustment
Due to possible pharmacodynamic interactions, a reduction in dosage of Precedex or other concomitant anesthetics, sedatives, hypnotics or opioids may be required when co-administered.
Dosage reductions may need to be considered for adult patients with hepatic impairment, and geriatric patients.
Preparation Of Solution
Strict aseptic technique must always be maintained during handling of Precedex.
Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit.
Precedex Injection, 200 mcg/2 mL (100 mcg/mL)
Precedex 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 infusion, withdraw 2 mL of Precedex Injection, and add to 48 mL of 0.9% sodium chloride injection to a total of 50 mL. Shake gently to mix well.
Precedex in 0.9% Sodium Chloride Injection, 80 mcg/20 mL (4 mcg/mL), 200 mcg/50 mL (4 mcg/mL) And 400 mcg/100 mL (4 mcg/mL)
Precedex in 0.9% Sodium Chloride Injection is supplied in glass containers containing a premixed, ready to use dexmedetomidine hydrochloride solution in 0.9% sodium chloride in water. No further dilution of these preparations are necessary.
Administration With Other Fluids
Precedex infusion should not be co-administered through the same intravenous catheter with blood or plasma because physical compatibility has not been established.
Precedex has been shown to be incompatible when administered with the following drugs: amphotericin B, diazepam.
Precedex has been shown to be compatible when administered with the following intravenous fluids:
- 0.9% sodium chloride in water
- 5% dextrose in water
- 20% mannitol
- Lactated Ringer's solution
- 100 mg/mL magnesium sulfate solution
- 0.3% potassium chloride solution
Compatibility With Natural Rubber
Compatibility studies have demonstrated the potential for absorption of Precedex to some types of natural rubber. Although Precedex is dosed to effect, it is advisable to use administration components made with synthetic or coated natural rubber gaskets.
None
WARNINGS
Included as part of the PRECAUTIONS section.
PRECAUTIONS
Drug Administration
Precedex 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 Precedex, patients should be continuously monitored while receiving Precedex.
Hypotension, Bradycardia, And Sinus Arrest
Clinically significant episodes of bradycardia and sinus arrest have been reported with Precedex 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 Precedex infusion. Some of these cases have resulted in fatalities. If medical intervention is required, treatment may include decreasing or stopping the infusion of Precedex, increasing the rate of intravenous fluid administration, elevation of the lower extremities, and use of pressor agents. Because Precedex 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 Precedex-induced bradycardia. However, in some patients with significant cardiovascular dysfunction, more advanced resuscitative measures were required.
Caution should be exercised when administering Precedex to patients with advanced heart block and/or severe ventricular dysfunction. Because Precedex 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 Precedex an additive pharmacodynamic effect was not observed. Nonetheless, caution should be used when such agents are administered concomitantly with Precedex.
Transient Hypertension
Transient hypertension has been observed primarily during the loading dose in association with the initial peripheral vasoconstrictive effects of Precedex. Treatment of the transient hypertension has generally not been necessary, although reduction of the loading infusion rate may be desirable.
Arousability
Some patients receiving Precedex 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.
Withdrawal
Intensive Care Unit Sedation
With administration up to 7 days, regardless of dose, 12 (5%) Precedex adult subjects experienced at least 1 event related to withdrawal within the first 24 hours after discontinuing study drug and 7 (3%) Precedex 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.
In adult subjects, tachycardia and hypertension requiring intervention in the 48 hours following study drug discontinuation occurred at frequencies of < 5%. If tachycardia and/or hypertension occurs after discontinuation of Precedex supportive therapy is indicated.
Procedural Sedation
In adult subjects, withdrawal symptoms were not seen after discontinuation of short term infusions of Precedex ( < 6 hours).
Tolerance And Tachyphylaxis
Use of dexmedetomidine beyond 24 hours has been associated with tolerance and tachyphylaxis and a dose-related increase in adverse reactions.
Hepatic Impairment
Since Precedex clearance decreases with severity of hepatic impairment, dose reduction should be considered in patients with impaired hepatic function.
Nonclinical Toxicology
Carcinogenesis, Mutagenesis, Impairment Of Fertility
Animal carcinogenicity studies have not been performed with dexmedetomidine.
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.
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.
Use In Specific Populations
Pregnancy
Pregnancy Category C
There are no adequate and well-controlled studies of Precedex use in pregnant women. In an in vitro human placenta study, placental transfer of dexmedetomidine occurred. In a study in the pregnant rat, placental transfer of dexmedetomidine was observed when radiolabeled dexmedetomidine was administered subcutaneously. Thus, fetal exposure should be expected in humans, and Precedex should be used during pregnancy only if the potential benefits justify the potential risk to the fetus.
Teratogenic effects were not observed in rats following subcutaneous administration of dexmedetomidine during the period of fetal organogenesis (from gestation day 5 to 16) with doses up to 200 mcg/kg (representing a dose approximately equal to the maximum recommended human intravenous dose based on body surface area) or in rabbits following intravenous administration of dexmedetomidine during the period of fetal organogenesis (from gestation day 6 to 18) with doses up to 96 mcg/kg (representing approximately half the human exposure at the maximum recommended dose based on plasma area under the time-curve comparison). However, fetal toxicity, as evidenced by increased post-implantation losses and reduced live pups, was observed in rats at a subcutaneous dose of 200 mcg/kg. The no-effect dose in rats was 20 mcg/kg (representing a dose less than the maximum recommended human intravenous dose based on a body surface area comparison). In another reproductive toxicity study when dexmedetomidine was administered subcutaneously to pregnant rats at 8 and 32 mcg/kg (representing a dose less than the maximum recommended human intravenous dose based on a body surface area comparison) from gestation day 16 through weaning, lower offspring weights were observed. Additionally, when offspring of the 32 mcg/kg group were allowed to mate, elevated fetal and embryocidal toxicity and delayed motor development was observed in second generation offspring.
Labor And Delivery
The safety of Precedex during labor and delivery has not been studied.
Nursing Mothers
It is not known whether Precedex is excreted in human milk. Radio-labeled dexmedetomidine administered subcutaneously to lactating female rats was excreted in milk. Because many drugs are excreted in human milk, caution should be exercised when Precedex is administered to a nursing woman.
Pediatric Use
Safety and efficacy have not been established for Procedural or ICU Sedation in pediatric patients. One assessor-blinded trial in pediatric patients and two open label studies in neonates were conducted to assess efficacy for ICU sedation. These studies did not meet their primary efficacy endpoints and the safety data submitted were insufficient to fully characterize the safety profile of Precedex for this patient population. The use of Precedex for procedural sedation in pediatric patients has not been evaluated.
Geriatric Use
Intensive Care Unit Sedation
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 Precedex. Therefore a dose reduction may be considered in patients over 65 years of age.
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 Precedex-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.
Hepatic Impairment
Since Precedex clearance decreases with increasing severity of hepatic impairment, dose reduction should be considered in patients with impaired hepatic function.
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.
Pregnancy Category C
There are no adequate and well-controlled studies of Precedex use in pregnant women. In an in vitro human placenta study, placental transfer of dexmedetomidine occurred. In a study in the pregnant rat, placental transfer of dexmedetomidine was observed when radiolabeled dexmedetomidine was administered subcutaneously. Thus, fetal exposure should be expected in humans, and Precedex should be used during pregnancy only if the potential benefits justify the potential risk to the fetus.
Teratogenic effects were not observed in rats following subcutaneous administration of dexmedetomidine during the period of fetal organogenesis (from gestation day 5 to 16) with doses up to 200 mcg/kg (representing a dose approximately equal to the maximum recommended human intravenous dose based on body surface area) or in rabbits following intravenous administration of dexmedetomidine during the period of fetal organogenesis (from gestation day 6 to 18) with doses up to 96 mcg/kg (representing approximately half the human exposure at the maximum recommended dose based on plasma area under the time-curve comparison). However, fetal toxicity, as evidenced by increased post-implantation losses and reduced live pups, was observed in rats at a subcutaneous dose of 200 mcg/kg. The no-effect dose in rats was 20 mcg/kg (representing a dose less than the maximum recommended human intravenous dose based on a body surface area comparison). In another reproductive toxicity study when dexmedetomidine was administered subcutaneously to pregnant rats at 8 and 32 mcg/kg (representing a dose less than the maximum recommended human intravenous dose based on a body surface area comparison) from gestation day 16 through weaning, lower offspring weights were observed. Additionally, when offspring of the 32 mcg/kg group were allowed to mate, elevated fetal and embryocidal toxicity and delayed motor development was observed in second generation offspring.
Clinical Studies 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 clinical trials of another drug and may not reflect the rates observed in practice.
Use of Precedex has been associated with the following serious adverse reactions:
- Hypotension, bradycardia and sinus arrest
- Transient hypertension
Most common treatment-emergent adverse reactions, occurring in greater than 2% of 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 Precedex for sedation in the Intensive Care Unit setting in which 1007 adult patients received Precedex. 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.
Table 2: Adverse Reactions with an Incidence
> 2%-Adult Intensive Care Unit Sedation Population < 24 hours*
| Adverse Event | All Precedex (N = 1007) (%) |
Randomized Precedex (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% |
| T achycardia | 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 Precedex group and 10 subjects in the randomized Precedex group had exposure for greater than 24 hours. |
Adverse reaction information was also derived from the placebo-controlled, continuous infusion trials of Precedex for sedation in the surgical intensive care unit setting in which 387 adult patients received Precedex for less than 24 hours. The most frequently observed treatment-emergent adverse events included hypotension, hypertension, nausea, bradycardia, fever, vomiting, hypoxia, tachycardia and anemia (see Table 3).
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% |
In a controlled clinical trial, Precedex was compared to midazolam for ICU sedation exceeding 24 hours duration in adult patients. Key treatment emergent adverse events occurring in dexmedetomidine or midazolam treated patients in the randomized active comparator continuous infusion long-term intensive care unit sedation study are provided in Table 4. The number (%) of subjects who had a doserelated increase in treatment-emergent adverse events by maintenance adjusted dose rate range in the Precedex group is provided in Table 5.
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. 1Hypotension 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. 2Bradycardia was defined in absolute terms as < 40 bpm or in relative terms as ≤ 30% lower than pre-study drug infusion value. 3Hypertension 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. 4Tachycardia was defined in absolute terms as > 120 bpm or in relative terms as ≥ 30% greater than pre-study drug infusion value. |
The following adverse events occurred between 2 and 5% for Precedex and Midazolam, respectively: renal failure acute (2.5%, 0.8%), acute respiratory distress syndrome (2.5%, 0.8%), and respiratory failure (4.5%, 3.3%).
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 Precedex Group
| 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 |
Procedural Sedation
Adverse reaction information is derived from the two trials for procedural sedation in which 318 adult patients received Precedex. 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 at an incidence of > 2% are provided in Table 6. The most frequent adverse reactions were hypotension, bradycardia, and dry mouth. 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 Precedex and comparator groups in both studies.
Table 6: Adverse Reactions With an Incidence >
2%-Procedural Sedation Population
| Adverse Event | Precedex (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. 2Respiratory depression was defined in absolute and relative terms as respiratory rate (RR) < 8 beats per minute or > 25% decrease from baseline. 3Bradycardia was defined in absolute and relative terms as < 40 beats per minute or ≤ 30% lower than pre-study drug infusion value. 4Hypertension 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. 6Hypoxia was defined in absolute and relative terms as SpO < 90% or 10% decrease from baseline. |
Postmarketing Experience
The following adverse reactions have been identified during post approval use of Precedex. 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 Precedex during post approval use of the drug.
Table 7: Adverse Reactions Experienced During Post-approval
Use of Precedex
| 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 |
The tolerability of Precedex 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 Precedex 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 Precedex (19.4 mcg/kg), had cardiac arrest from which he was successfully resuscitated.
In a study in healthy volunteers (N = 10), respiratory rate and oxygen saturation remained within normal limits and there was no evidence of respiratory depression when Precedex was administered by intravenous infusion at doses within the recommended dose range (0.2-0.7 mcg/kg/hr).
Following intravenous administration, dexmedetomidine exhibits the following pharmacokinetic parameters: a rapid distribution phase with a distribution half-life (t½) of approximately 6 minutes; a terminal elimination half-life (t½) 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 by intravenous infusion for up to 24 hours. Table 8 shows the main pharmacokinetic parameters when Precedex 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
| 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) | ||||
| Parameter | 0.3/0.17 | 0.3/0.17 | 0.6/0.33 | 1.25/0.70 |
| t½*, 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 |
| *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 postdose 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.
Dexmedetomidine pharmacokinetic parameters after Precedex maintenance doses of 0.2 to 1.4 mcg/kg/hr for > 24 hours were similar to the PK parameters after Precedex maintenance dosing for < 24 hours in other studies. The values for clearance (CL), volume of distribution (V), and t½ were 39.4 L/hr, 152 L, and 2.67 hours, 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 Precedex 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 Precedex were observed. The potential for protein binding displacement of phenytoin, warfarin, ibuprofen, propranolol, theophylline and digoxin by Precedex was explored in vitro and none of these compounds appeared to be significantly displaced by Precedex.
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-carboxydexmedetomidine; and N-methylation of dexmedetomidine to generate 3-hydroxy N-methyldexmedetomidine, 3-carboxy N-methyl-dexmedetomidine, and dexmedetomidine-N-methyl Oglucuronide.
Elimination
The terminal elimination half-life (t½) 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 Nglucuronidation 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.
Gender
There was no observed difference in Precedex pharmacokinetics due to gender.
Geriatrics
The pharmacokinetic profile of Precedex was not altered by age. There were no differences in the pharmacokinetics of Precedex in young (18-40 years), middle age (41-65 years), and elderly ( > 65 years) subjects.
Hepatic Impairment
In subjects with varying degrees of hepatic impairment (Child-Pugh Class A, B, or C), clearance values for Precedex 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 subjects, respectively. Mean clearances for free drug were 59%, 51% and 32% of those observed in the normal healthy subjects, respectively.
Although Precedex is dosed to effect, it may be necessary to consider dose reduction in subjects with hepatic impairment.
Renal Impairment
Dexmedetomidine pharmacokinetics (Cmax, Tmax, AUC, t½, CL, and Vss) were not significantly different in patients with severe renal impairment (creatinine clearance: < 30 mL/min) compared to healthy subjects.
