Dexmedetomidine: a magic bullet on its way into palliative care-a narrative review and practice recommendations

Dexmedetomidine is a potent adrenergic alpha-2 receptor agonist. It was first approved for sedation for mechanically ventilated patients. Being a sedative medication that is not associated with respiratory depression and holding analgesic properties fosters the interest for this drug in the palliative care field. The primary objectives of this review were to identify the key indications for the real-world use of dexmedetomidine in palliative care and other disciplines.

A narrative review after extensive PubMed search was performed from 1950 to present on October 21st 2021. The language of the publications was restricted to English, German, French and Italian.

(I) Current dexmedetomidine use. There is a growing body of evidence that dexmedetomidine may reduce the incidence and severity of delirium, reduce opioid-consumption and postoperative nausea in intensive care settings. It is also used to facilitate withdrawal from different substances (alcohol, opioids, heroin). Concerning safety aspects of the drug, some studies reported an increased rate of serious cardiovascular events in patients with pre-existing heart conditions due to bradycardia and arterial hypo- and hypertension. Since the drug has a main hepatic metabolism, dose reduction is mandatory in patients with hepatic impairment. (II) Dexmedetomidine and palliative care. There have been sporadic case reports about the successful use of dexmedetomidine in palliative care. Indications for symptom control included sedation for hyperactive delirium, cancer pain, opioid-induced-hyperalgesia, dystonia, cough, vomiting, shivering and dyspnea. It is mainly applied via the intravenous (i.v.), subcutaneous, but also nasal and, buccal routes. Admixture ("syringe-driver") studies showed that dexmedetomidine is compatible with morphine, hydromorphone, hyoscine and haloperidol. In 2021, a first prospective cohort study became available. Here, the authors reported promising result for dexmedetomidine use in hyperactive terminal delirium for reducing delirium intensity and agitation. Especially the unique "conscious sedation" or "awake sedation" that allows patients to arouse easily under sedation and report comfort or distress was discussed by the authors.

In this review, we present the main findings for dexmedetomidine from palliative care settings and other disciplines. The potential benefits and criticalities of the drug are discussed and practical recommendations for its use are provided.