Comparing Dexmedetomidine With Midazolam for Sedation of Patients in the ICU

To the Editor: Dr Riker and colleagues¹ compared midazolam vs dexmedetomidine for sedation in ICU patients. In Figure 1, of the initial 420 patients who provided consent, 1 patient was excluded for “drug dependence.” However, since the initial study protocol did not state that patients with drug dependence were to be excluded, it was unclear why this occurred.

Dexmedetomidine is an imidazole compound that displays specific and selective α₂-adrenoreceptor affinity and has about 8 times greater affinity for the receptor than clonidine.² Clonidine has been used as a second-line agent for the treatment of alcohol withdrawal.³ Dexmedetomidine has multiple characteristics that indicate potential for the treatment of alcohol withdrawal. These include reducing heart rate, lowering systemic blood pressure, and providing sedation. Case reports show positive outcomes for dexmedetomidine use in alcohol-withdrawal patients.⁴ In addition, rodent studies show dexmedetomidine to alleviate symptoms in ethanol-dependent rats.⁵ Dexmedetomidine may also be helpful in patients with severe withdrawal from other agents acting on GABA receptors. We have noted dexmedetomidine being used in our ICU as a second-line agent for the treatment of alcohol-withdrawal syndrome in nonintubated patients.