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.  A loading dose may not be required if transitioning off other sedatives.

• Loading dose if used: 1 mcg/kg over 20 – 30 minutes. Comes a premixed solution. If a loading dose is required, deliver it from the bag via infusion pump.

Maintenance infusion: 

• Start at 0.2 - 0.4 mcg/kg/hour and titrate by 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.

Dexmedetomidine has been continuously infused in mechanically ventilated patients prior to extubation, during extubation, and post-extubation. It is not necessary to discontinue dexmedetomidine prior to extubation. 

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 benzodiazepines slowly as dose of dexmedetomidine is titrated upward
• Goal is to discontinue all other sedatives within 24 hours of starting dexmedetomidine
• Caution: patients who are on chronic benzodiazepines/narcotics may require 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 

• 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 administration 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

• 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

• 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