From the Guidelines
Dexmedetomidine is recommended for sedation in critically ill, mechanically ventilated adults, with a suggested dosing of 0.2-0.7 μg/kg/hr, due to its ability to provide sedation without significant respiratory depression, as supported by the most recent guidelines 1. The recommended dosing for ICU sedation begins with a loading dose of 1 mcg/kg over 10 minutes, followed by a maintenance infusion of 0.2-0.7 mcg/kg/hour, which may be adjusted to achieve the desired level of sedation.
- The onset of sedation occurs within 15 minutes and peak sedation occurs within 1 hour of starting an IV infusion of dexmedetomidine 1.
- Dexmedetomidine provides sedation without significant respiratory depression, which is its main advantage over other sedatives, such as propofol and benzodiazepines 1.
- However, it can cause hypotension, bradycardia, and dry mouth, and continuous cardiac monitoring is required during administration 1.
- The drug works by stimulating alpha-2 receptors in the locus coeruleus, reducing norepinephrine release and sympathetic activity, resulting in sedation, anxiolysis, and some analgesic effects without respiratory depression 1.
- The clinical pharmacology of sedatives prescribed for ICU patients is summarized in Table 6, which highlights the differences between dexmedetomidine and other sedatives, such as midazolam, lorazepam, and propofol 1.
From the FDA Drug Label
DOSAGE AND ADMINISTRATION Dogs - 0. 1 Sedation and Analgesia: 500 mcg/m2 intramuscularly (IM) or 375 mcg/m2 intravenously (IV). The following two tables may be used to determine the correct dexmedetomidine dosage. Table 1: CANINE SEDATION/ANALGESIA DOSE TABLE: Intravenous (IV) and intramuscular (IM) dosing on the basis of body weight. Table 2: CANINE PREANESTHESIA DOSE TABLE: Intramuscular (IM) dosing on the basis of body weight. Cats - 0. 1 Sedation, Analgesia and Preanesthesia: 40 mcg/kg intramuscularly (IM). Table 3: FELINE DOSE TABLE: Intramuscular (IM) dosing on the basis of body weight in cats.
The official guidelines for dexmedetomidine are as follows:
- Dogs:
- Sedation and analgesia: 500 mcg/m2 IM or 375 mcg/m2 IV
- Preanesthesia: 125 or 375 mcg/m2 IM
- Cats:
- Sedation, analgesia, and preanesthesia: 40 mcg/kg IM It is recommended to fast dogs and cats for 12 hours before treatment with dexmedetomidine 2. Key considerations:
- Accurate dosing is not possible in dogs weighing less than 2 kg (4.4 lb) 2
- Dexmedetomidine should not be administered in the presence of preexisting hypotension, hypoxia, or bradycardia 2
- Animals should be frequently monitored for cardiovascular function and body temperature during sedation or anesthesia 2
From the Research
Official Guidelines for Dexmedetomidine
The official guidelines for dexmedetomidine are as follows:
- Dexmedetomidine is indicated in the US for the sedation of mechanically ventilated adult patients in an intensive care setting and in non-intubated adult patients prior to and/or during surgical and other procedures 3.
- The pharmacological properties and possible adverse effects of dexmedetomidine should be well understood by the anesthesiologist prior to use 4.
- Dexmedetomidine may produce less delirium than other sedatives or even prevent delirium 4, 3, 5.
- The analgesic effect of dexmedetomidine is not strong; however, it can be administered as a useful analgesic adjuvant 4.
- Dexmedetomidine-induced cooperative sedation with minimal respiratory depression provides safe and acceptable conditions during neurosurgical procedures in awake patients and awake fiberoptic intubation 4.
Adverse Effects
The adverse effects of dexmedetomidine include:
- Hypotension and bradycardia, which usually resolve without intervention 6, 3, 7, 5.
- Cardiac arrest following severe bradycardia, although this is rare 4.
- Respiratory depression is not typically associated with dexmedetomidine 6, 3.