DEXMEDETOMIDINE (Precedex)

Short acting sedation, alpha2 agonist

• Sedative, anxiolytic, analgesia and sympatholytic agent
• Potent and relatively selective alpha-2-adrenergic receptor agonist with sedative properties
• May be continuously infused in mechanically ventilated patients prior to extubation, during extubation and post-extubation
• May be used for sedation in non-intubated patients prior to and/or during certain procedures
• May have alternative roles in analgesia, delirium and ethanol withdrawal

Loading dose: 

Recommend starting infusion at 0.4 mcg/kg/hour WITHOUT loading dose in most patients as this has decreased the incidence of bradycardia.

• Loading dose of 1 mcg/kg over 20 – 30 minutes
• Precedex must be diluted in 0.9% sodium chloride solution to achieve required concentration (4 mcg/mL) prior to administration.
  • A loading dose may not be required if transitioning a patient from other sedatives

Maintenance infusion: 

• Start at 0.2 - 0.4 mcg/kg/hour and titrate to 0.1 - 0.2 mcg/kg/hour every 30 minutes to a maximum rate of 1.1 mcg/kg/hour
• Adjust rate to achieve the targeted level of sedation

Maximum Duration:

• Use beyond 24 h should be reviewed daily by physician.

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. After extubation, the dose of Precedex should be reduced by half. The mean time of continued infusion is approximately 6.6 hours.

How to transition to dexmedetomidine:

• One hour after initiation of dexmedetomidine infusion, reduce narcotic dose by 50%
• Discontinue all other antipsychotics
• Wean propofol and/or benzodiapines slowly as dose of dexmedetomidine is titrated upward
• Goal is to discontinue all other antipscyhotic and sedatives within 24 hours of starting dexmedetomidine
• Caution: patients who are on chronic benzodiapepines/narcotics may required continued use

Stopping dexmedetomidine:

• Once patient is extubated or stable on tracheostomy mask, decrease dexmedetomidine dose by 50% and discontinue one hour later
• Depending on patient and history, may need to transition to clonidine and wean clonidine off slowly over a few days/ week
• If indicated, start clonidine while on dexmedetomidine

• Continuous intravenous infusion 400mcg in 100mL sodium chloride 0.9%

• Hypotension (most common adverse effect, often transient and responsive to phenylephrine rescue)

• Bradycardia (may be treated with atropine)
• Sinus arrest
• Dry mouth
• Nausea
• Lack of respiratory depression
• Transient hypertension (most common during loading dose; reduced administartion rate)
• May experience increased alertness or arousal upon stimulation; in isolation this should not be considered as lack of efficacy
• Prolonged exposure to dexmedetomidine beyond 24 hours may be
  associated with tolerance and tachyphylaxis and a dose-related
  increase in adverse events (including ARDS, respiratory failure and agitation)

• Use with caution in heart block or severe left ventricular dysfunction
• Bradycardia and sinus arrest have occurred in healthy volunteers with high vagal tone or in patients who received rapid IV administration
• Hypotension and bradycardia may be more pronounced in patients with hypovolemia, diabetes mellitus, chronic hypertension or in elderly
• Consider dose reduction in elderly and hepatic failure
• Should not be used during pregnancy
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• Dexmedetomidine + other anesthetics, sedatives, hypnotics, opioids may lead to enhancement of effects (analgesic requirements may be significantly reduced)

• Dexmedetomidine + vasodilators or negative chronotropic agents may lead to additive pharmacodynamic effects

• continuous heart rate and rhythm
• blood pressure
• pain, agitation and delirium
• oxygen saturation
• weaning from mechanical ventilation and readiness for extubation

• Non-formulary medication at LHSC – must seek approval prior to use

• May be administered by IV infusion and titrated by a nurse in Adult Critical Care

• Continuous infusions must be administered by infusion device and the pump library must be enabled.

• Placement of an arterial line for blood pressure monitoring is preferred