Alpha-2 Agonist Sedative
Pregnancy: C — limited data
Dexmedetomidine
Brand names: Precedex, Dexdor
Adult dose
Dose: ICU sedation: 0.2–1.4 micrograms/kg/hr. Loading dose: 1 mcg/kg over 10 min (optional — often omitted in ICU to avoid haemodynamic effects)
Route: IV infusion
Frequency: Continuous infusion
Procedural sedation: 1 mcg/kg loading over 10 min, then 0.2–1 mcg/kg/hr. Awake fibreoptic intubation: 1 mcg/kg over 10 min.
Paediatric dose
Dose: 0.5 mcg/hour/kg
Route: IV infusion
Frequency: Continuous
Range 0.2–1 mcg/kg/hr (paediatric off-label ICU sedation). Procedural: 1–2 mcg/kg loading over 10 min.
Paediatric weight-based calculator
Range 0.2–1 mcg/kg/hr (paediatric off-label ICU sedation). Procedural: 1–2 mcg/kg loading over 10 min.
Clinical pearls
- Cooperative sedation: patient can be roused for neurological assessment — ideal for ICU
- Analgesic-sparing, anxiolytic — reduces opioid requirements
- MENDS2 and PRODEX trials: non-inferior to propofol/midazolam with less delirium
- Does NOT cause respiratory depression at clinical doses — unique advantage
- Avoid loading dose in haemodynamically unstable patients — start infusion at low rate instead
Contraindications
- Advanced heart block (2nd or 3rd degree) without pacemaker
- Severe haemodynamic instability
Side effects
- Bradycardia
- Hypotension
- Transient hypertension (during loading — alpha-1 mediated)
- Dry mouth
- Nausea
Interactions
- Beta-blockers — additive bradycardia and hypotension
- Anaesthetic agents — dose-sparing effect
Monitoring
- Heart rate and rhythm (ECG continuous)
- Blood pressure (continuous)
- Level of sedation (RASS target 0 to -2)
- Respiratory rate
Reference: BNFc; MENDS2 trial (NEJM 2021); ESICM Sedation Guidelines; BNF. Verify against your local formulary and the latest BNF before prescribing.
Related
Curated clinical cross-links plus same-class fallbacks.