( S ) -4- [1- (2,3-Dimethylphenyl) ethyl] -3 H -imidazole
|Molecular formula||C 13 H 16 N 2|
|External identifiers / databases|
|Mechanism of action||
α 2 adrenoreceptor agonist
|Molar mass||200.28 g · mol -1|
soluble in water and DMSO
|As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .|
Mechanism of action
Dexmedetomidine activated similar to clonidine dose-dependent α 2 - adrenoceptors and thus decreases the release of noradrenaline . This happens especially in the locus caeruleus in the brain stem, which is involved in the control of attention and alertness. Allegedly, this specific mechanism of action leads to a sleep-like state from which patients can immediately wake up when spoken to and are able to communicate or follow instructions. Furthermore, α 2 -adrenoceptors of the sympathetic nervous system are activated, which leads to its inhibition ( sympathicolysis ).
Compared to other sedatives
If you consider the use as a sedative in the intensive care unit, the following benefits are advertised:
- better controllability of the depth and duration of sedation compared to benzodiazepines
- possible long-term use over several weeks in contrast to propofol
- Less habituation and dependency development compared to benzodiazepines and opioids .
One disadvantage is the higher price, which is why it is not used that often. And as with clonidine, watch out for bradycardia and decrease in blood pressure.
As a side effect, the usual low doses in the context of the inhibition of the sympathetic nervous system sympathicolysis lead to a decrease in heart rate and blood pressure . At high concentrations, such as those that can arise briefly from rapid intravenous injection, the peripheral vasoconstricting effect of dexmedetomidine predominates, so that the blood pressure increases.
Dexmedetomidine has been approved in Germany for the sedation of adult, intensive care patients since 2011. In the context of studies, there is experience with the use in children in the context of off-label use . In its meeting in June 2018, the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency ( EMA) recommended an extension of the authorization for dexmedetomidine: In the future, the sedative should be used to sedate non-intubated patients before and / or during diagnostic or surgical measures, if sedation is necessary (“procedural / awake sedation”). As a rule, the European Commission complies with such a recommendation ( positive vote ).
Contraindications for the use of the substance exist in the case of known intolerance, uncontrolled low blood pressure, AV block II - III and acute cerebrovascular events.
- Cepedex , Dexdomitor , Dexdor , Dexmopet , Sedadex , Sileo
- H. Ihmsen, TI Saari: Dexmedetomidine. In: The anesthesiologist. 61, 2012, pp. 1059-1066, doi: 10.1007 / s00101-012-2114-1 .