Dexmedetomidine Prescribing Guideline (235)

A guideline is intended to assist healthcare professionals in the choice of disease-specific treatments.

Clinical judgement should be exercised on the applicability of any guideline, influenced by individual patient characteristics. Clinicians should be mindful of the potential for harmful polypharmacy and increased susceptibility to adverse drug reactions in patients with multiple morbidities or frailty.

If, after discussion with the patient or carer, there are good reasons for not following a guideline, it is good practice to record these and communicate them to others involved in the care of the patient.

Introduction

Dexmedetomidine is an alpha 2-agonist with around 8 times the potency of clonidine. It is significantly more expensive than currently available agents such as propofol and midazolam. It is ineffective for achieving deep sedation and should not be used in patients receiving muscle relaxants. At doses used for light sedation it has more adverse haemodynamic effects when compared to midazolam (MIDEX study) but a similar number to propofol.(PRODEX study)

Because of the notably higher cost, use of dexmedetomidine should be restricted and it should not be considered a first line treatment. Some gain in using dexmedetomidine may be found in the following situations -

1. Patients whose sedative requirement is challenging to manage and where somnolent effects are not desired and who may benefit from anxiolysis.

2. In the period prior to extubation. Dexmedetomidine’s relative short time of action and lack of respiratory depression may be helpful.

3. Patients on non invasive ventilation. Dexmedetomidine may be useful because of a lack of respiratory suppression and a quicker onset of action compared to clonidine.

Dosage

Start at an initial infusion rate of 0.7micrograms/kg/hour. Higher initial doses may be required in patients who are very agitated but the maximum dose of 1.4micrograms/kg/hour should not be exceeded.

Dosing is based on actual body weight. Do not administer a loading dose. No dosage adjustment is required for patients with renal impairment but as dexmedetomidine is metabolised in the liver it should be used in caution in patients with hepatic impairment.

Dose Titration

Adjust stepwise within the dose range of 0.2 – 1.4micrograms/kg/hour to achieve the desired level of sedation. Dose increments and the rate of titration should be dictated by the needs of the patient.

Dose titration may be difficult particularly when other sedative agents are being weaned simultaneously. It is recommended that individual regimes should be tailored for each patient commenced on dexmedetomidine.

If after adequate time at maximum dose the desired effect is not achieved then re-evaluate the use of this agent.

Preparation

Dilute 400microgram/4ml vial with 96ml Glucose 5% or Sodium Chloride 0.9%. This gives a solution of 4micrograms/ml.

Contact your clinical pharmacist if a more concentrated solution is required.

Administration

Dexmedetomidine can be administered centrally or peripherally.

Compatibility

Dexmedetomidine is compatible with:-Glucose 5% and Sodium Chloride 0.9%.

Compatibility information with other medicines can be found in the Summary of Product Characteristics.

Dexmedetomidine (Dexdor®) - summary of product characteristics at www.medicines.org.uk