Dexmedetomidine
Encyclopedia
Dexmedetomidine is a sedative
medication used by intensive care units and anesthetists. It is relatively unique in its ability to provide sedation without causing respiratory depression. Like clonidine
, it is an agonist
of α2-adrenergic receptor
s in certain parts of the brain.
, dexmedetomidine was similarly effective for sedation, but shortened the time to extubation. It was associated with less delirium
, tachycardia
and hypotension
. but more bradycardia
. It also seemed to be superior to lorazepam for ventilated
patients in the intensive care unit
. Compared to midazolam, dexmedetomidine is superior due to reduced intensive care costs. The reduced costs are due to a reduction in intensive care unit
stay as well as reduced mechanical ventilation
.
, sympatholytic
, and anxiolytic
effects that blunt many of the cardiovascular responses in the perioperative
period. It reduces the requirements for volatile anesthetics, sedatives and analgesics without causing significant respiratory depression.
intoxication
and overdose. Dexmedetomidine may also offer a new paradigm in the pharmacologic treatment of symptoms of distress (intractable pain, agitation or delirium) at the end of life. Recently, an investigator initiated IND was approved by the FDA to examine the use of dexmedetomidine in treating cancer patients at the end of life who are suffering from intractable pain, agitation or delirium.
Sedative
A sedative or tranquilizer is a substance that induces sedation by reducing irritability or excitement....
medication used by intensive care units and anesthetists. It is relatively unique in its ability to provide sedation without causing respiratory depression. Like clonidine
Clonidine
Clonidine is a sympatholytic medication used to treat medical conditions, such as high blood pressure, some pain conditions, ADHD and anxiety/panic disorder...
, it is an agonist
Agonist
An agonist is a chemical that binds to a receptor of a cell and triggers a response by that cell. Agonists often mimic the action of a naturally occurring substance...
of α2-adrenergic receptor
Alpha-2 adrenergic receptor
The alpha-2 adrenergic receptor is a G protein-coupled receptor associated with the Gi heterotrimeric G-protein. It consists of three highly homologous subtypes, including α2A-, α2B-, and α2C-adrenergic. Some species other than humans express a fourth α2D-adrenergic receptor as well...
s in certain parts of the brain.
Indications
Dexmedetomidine is indicated for sedation of critically ill or injured patients in an intensive care unit setting. Its indication in the US was recently expanded to include nonintubated patient requiring sedation for surgery or procedures short-term. It is also useful as an adjunct for sedation and general anesthesia in the setting of certain operations and invasive medical procedures, such as colonoscopy. There are no absolute contraindications to the use of dexmedetomidine. Limiting its usefulness is the caution that the drug cannot be bolused due to concerns about peripheral α2-receptor stimulation with resulting hypotension, combined with its high cost relative to generic medications like propofol, fentanyl and midazolam which can achieve similar clinical effectsIntensive care unit sedation
Compared to midazolamMidazolam
Midazolam is a short-acting drug in the benzodiazepine class developed by Hoffmann-La Roche in the 1970s. The drug is used for treatment of acute seizures, moderate to severe insomnia, and for inducing sedation and amnesia before medical procedures. It possesses profoundly potent anxiolytic,...
, dexmedetomidine was similarly effective for sedation, but shortened the time to extubation. It was associated with less delirium
Delirium
Delirium or acute confusional state is a common and severe neuropsychiatric syndrome with core features of acute onset and fluctuating course, attentional deficits and generalized severe disorganization of behavior...
, tachycardia
Tachycardia
Tachycardia comes from the Greek words tachys and kardia . Tachycardia typically refers to a heart rate that exceeds the normal range for a resting heart rate...
and hypotension
Hypotension
In physiology and medicine, hypotension is abnormally low blood pressure, especially in the arteries of the systemic circulation. It is best understood as a physiologic state, rather than a disease. It is often associated with shock, though not necessarily indicative of it. Hypotension is the...
. but more bradycardia
Bradycardia
Bradycardia , in the context of adult medicine, is the resting heart rate of under 60 beats per minute, though it is seldom symptomatic until the rate drops below 50 beat/min. It may cause cardiac arrest in some patients, because those with bradycardia may not be pumping enough oxygen to their heart...
. It also seemed to be superior to lorazepam for ventilated
Mechanical ventilation
In medicine, mechanical ventilation is a method to mechanically assist or replace spontaneous breathing. This may involve a machine called a ventilator or the breathing may be assisted by a physician, respiratory therapist or other suitable person compressing a bag or set of bellows...
patients in the intensive care unit
Intensive Care Unit
thumb|220px|ICU roomAn intensive-care unit , critical-care unit , intensive-therapy unit/intensive-treatment unit is a specialized department in a hospital that provides intensive-care medicine...
. Compared to midazolam, dexmedetomidine is superior due to reduced intensive care costs. The reduced costs are due to a reduction in intensive care unit
Intensive Care Unit
thumb|220px|ICU roomAn intensive-care unit , critical-care unit , intensive-therapy unit/intensive-treatment unit is a specialized department in a hospital that provides intensive-care medicine...
stay as well as reduced mechanical ventilation
Mechanical ventilation
In medicine, mechanical ventilation is a method to mechanically assist or replace spontaneous breathing. This may involve a machine called a ventilator or the breathing may be assisted by a physician, respiratory therapist or other suitable person compressing a bag or set of bellows...
.
Procedural sedation
Dexmedetomidine has sedative, analgesicAnalgesic
An analgesic is any member of the group of drugs used to relieve pain . The word analgesic derives from Greek an- and algos ....
, sympatholytic
Sympatholytic
A sympatholytic drug is a medication which inhibits the postganglionic functioning of the sympathetic nervous system . They are indicated for various functions, for example they may be used as antihypertensives...
, and anxiolytic
Anxiolytic
An anxiolytic is a drug used for the treatment of anxiety, and its related psychological and physical symptoms...
effects that blunt many of the cardiovascular responses in the perioperative
Perioperative
The perioperative period, less commonly spelled the peroperative period, is the time period describing the duration of a patient's surgical procedure; this commonly includes ward admission, anesthesia, surgery, and recovery. Perioperative generally refers to the three phases of surgery:...
period. It reduces the requirements for volatile anesthetics, sedatives and analgesics without causing significant respiratory depression.
Other
Dexmedetomidine may be useful for the treatment of the deleterious cardiovascular effects of acute cocaineCocaine
Cocaine is a crystalline tropane alkaloid that is obtained from the leaves of the coca plant. The name comes from "coca" in addition to the alkaloid suffix -ine, forming cocaine. It is a stimulant of the central nervous system, an appetite suppressant, and a topical anesthetic...
intoxication
Intoxication
Substance intoxication is a type of substance-induced disorder which is potentially maladaptive and impairing, but reversible, and associated with recent use.If the symptoms are severe, the term "substance intoxication delirium" may be used.-Classification:...
and overdose. Dexmedetomidine may also offer a new paradigm in the pharmacologic treatment of symptoms of distress (intractable pain, agitation or delirium) at the end of life. Recently, an investigator initiated IND was approved by the FDA to examine the use of dexmedetomidine in treating cancer patients at the end of life who are suffering from intractable pain, agitation or delirium.
Dosage and administration
Intravenous infusion of dexmedetomidine is commonly initiated with a 1 mcg/kg loading dose, administered over 10 minutes, followed by a maintenance infusion of 0.2–1.0 mcg/kg/hour. There may be great individual variability in the hemodynamic effects (especially on heart rate and blood pressure), as well as the sedative effects of this drug. For this reason, the dose must be carefully adjusted to achieve the desired clinical effect.See also
- XylazineXylazineXylazine is a drug that is used for sedation, anesthesia, muscle relaxation, and analgesia in animals such as horses, cattle and other non-human mammals. An analogue of clonidine, it is an agonist at the α2 class of adrenergic receptor....
, another α2-receptor agonist used in veterinary anesthesiaVeterinary anesthesiaVeterinary anesthesia is anesthesia performed on animals by a veterinarian. Anesthesia is used for a wider range of circumstances in animals than in people, due to animals' unwillingness to cooperate with certain diagnostic or therapeutic procedures...
. - MedetomidineMedetomidineMedetomidine is a synthetic drug used as both a surgical anesthetic and analgesic often used as the hydrochloride salt medetomidine hydrochloride. It is a crystalline white alpha-two adrenergic agonist that can be administered as an intravenous drug solution with sterile water...
, a racemicRacemicIn chemistry, a racemic mixture, or racemate , is one that has equal amounts of left- and right-handed enantiomers of a chiral molecule. The first known racemic mixture was "racemic acid", which Louis Pasteur found to be a mixture of the two enantiomeric isomers of tartaric acid.- Nomenclature :A...
mixture of R and S-enantiomers of Dexmedetomidine used in small animal anesthesia. - DetomidineDetomidineDetomidine is an imidazole derivative and α2-adrenergic agonist, used as a large animal sedative, primarily used in horses. It is usually available as the salt detomidine hydrochloride...
, a similar compound used largely in large animal anesthesia.