Dexmedetomidine, sold under the trade name Precedex among others, is a medication used for sedation. It is also used to treat acute agitation associated with schizophrenia or bipolar I or II disorder.Similar to clonidine, it is a sympatholytic drug that acts as an agonist of α2-adrenergic receptors in certain parts of the brain. Veterinarians use dexmedetomidine for similar purposes in treating cats, dogs, and horses. It was developed by Orion Pharma. Medical uses
Intensive care unit sedation
Studies suggest dexmedetomidine for sedation in mechanically ventilated adults may reduce time to extubation and ICU stay.Compared with other sedatives, some studies suggest dexmedetomidine may be associated with less delirium. However, this finding is not consistent across multiple studies. At the very least, when aggregating many study results together, use of dexmedetomidine appears to be associated with less neurocognitive dysfunction compared to other sedatives. Whether this observation has a beneficial psychological impact is unclear. From an economic perspective, dexmedetomidine is associated with lower ICU costs, largely due to a shorter time to extubation. Procedural sedation
Dexmedetomidine can also be used for procedural sedation such as during colonoscopy. It can be used as an adjunct with other sedatives like benzodiazepines, opioids, and propofol to enhance sedation and help maintain hemodynamic stability by decreasing the requirement of other sedatives. Dexmedetomidine is also used for procedural sedation in children.It can be used for sedation required for awake fibreoptic nasal intubation in patients with a difficult airway.
Other
Dexmedetomidine may be useful for the treatment of the negative cardiovascular effects of acute amphetamines and cocaine intoxication and overdose. Dexmedetomidine has also been used as an adjunct to neuroaxial anesthesia for lower limb procedures.In 2022 it was approved by the FDA for the treatment of agitation in schizophrenia and bipolar disorder. Side effects
There is no absolute contraindication to the use of dexmedetomidine. It has a biphasic effect on blood pressure with lower readings at lower drug concentrations and higher readings at higher concentrations. Interactions
Dexmedetomidine may enhance the effects of other sedatives and anesthetics when co-administered. Similarly, drugs that lower blood pressure and heart rate, such as beta blockers, may also have enhanced effects when co-administered with dexmedetomidine. Pharmacology
Pharmacodynamics
Dexmedetomidine is a highly selective α2-adrenergic  agonist. It possesses an α2:α1 selectivity ratio of 1620:1, making it eight times more selective for the α2-receptor than clonidine. Unlike opioids and other sedatives such as propofol, dexmedetomidine is able to achieve its effects without causing respiratory depression. Dexmedetomidine induces sedation by decreasing activity of noradrenergic neurons in the locus ceruleus in the brain stem, thereby increasing the downstream activity of inhibitory gamma-aminobutyric acid (GABA) neurons in the ventrolateral preoptic nucleus. In contrast, other sedatives like propofol and benzodiazepines directly increase activity of gamma-aminobutyric acid neurons. Through action on this endogenous sleep-promoting pathway the sedation produced by dexmedetomidine more closely mirrors natural sleep (specifically stage 2 non-rapid eye movement sleep), as demonstrated by EEG studies. As such, dexmedetomidine provides less amnesia than benzodiazepines.