Dexmedetomidine

INTRODUCTION

Indications

Sedation of initially intubated and mechanically ventilated patients during treatment in an intensive care setting; should not be used for >24 hr.

Action

Acts as a relatively selective alpha-adrenergic agonist with sedative properties. Therapeutic Effects: Sedation.

Adverse Reactions/Side Effects

Resp: hypoxia. CV: BRADYCARDIA, SINUS ARREST, hypotension, transient hypertension. GI: nausea, vomiting. Hemat: anemia. Misc: fever.

PHYSICAL THERAPY IMPLICATIONS

Examination and Evaluation

• Assess heart rate, ECG, and heart sounds (See Appendices G, H). Report slow heart rate (bradycardia) or symptoms of other arrhythmias, including palpitations, chest discomfort, fainting, and fatigue/weakness.

• Assess blood pressure (BP) and compare to normal values (See Appendix F). Report changes in BP, either a problematic decrease in BP (hypotension) or a sustained increase in BP (hypertension).

• Monitor signs of low oxygen levels (hypoxia) or anemia, including pallor and cyanosis. Monitor pulse oximetry to quantify suspected problems with mechanical ventilation or blood delivery to tissues.

Patient/Client-Related Instruction

• Instruct patient or family/caregivers to report other troublesome side effects such as severe or prolonged fever or GI problems (nausea, vomiting).

Pharmacokinetics

Absorption: IV administration results in complete bioavailability.

Distribution: Unknown.

Protein Binding: 94%.

Metabolism and Excretion: Mostly metabolized by the liver, some metabolism by P450 enzyme system. Metabolites are mostly excreted in urine.

Half-life: 2 hr.

Contraindications/Precautions

Contraindicated in: Hypersensitivity.

Use Cautiously in: Hepatic impairment (lower doses may be required); Advanced heart block; Geriatric patients (increased risk of bradycardia and hypotension in patients ≥65 yr; Pregnancy, lactation or children (safety not established).

Interactions

Drug-Drug: Sedation is enhanced by anesthetics, other sedative/hypnotics, and opioid analgesics.

Drug-Natural: Concomitant use of kava, valerian, skullcap, chamomile, or hops can ↑ CNS depression.

Route/Dosage

IV (Adults): Loading infusion—1 mcg/kg over 10 min followed by maintenance infusion of 0.2–0.7 mcg/kg/hr for maximum of 24 hr; rate is adjusted to achieve desired level of sedation.

Availability

Injection: 100 mcg/mL in 2-mL ampules and vials.