What is Remifentanil? 1
- Ultra-short-acting synthetic opioid analgesic.
- Used for pain management and as an adjunct to anesthesia.
- Rapid onset and short duration of action.
Mechanism of Action & Pharmacokinetics 12
- Acts primarily on mu-opioid receptors in the brain and spinal cord with minimal or no activity on delta and kappa opioid receptors.
- The mu receptor is predominantly responsible for analgesia, hypoventilation, and euphoria
- Rapidly metabolized by nonspecific esterases in blood and tissues, leading to quick clearance without redistribution.
Pharmacodynamics 12
Cardiovascular
- May decrease heart rate and blood pressure
- The degree of hypotension and bradycardia is dose-dependent, predictable, and quickly reversible due to rapid metabolism.
Respiratory
- Can cause skeletal muscle and chest wall rigidity, particularly with continuous infusion, leading to decreased minute ventilation, respiratory depression, and apneas.
Indications 1
- Induction and maintenance of general anesthesia.
- Analgesia during short/intense surgical procedures.
- MAC sparing agent, reducing the MAC of inhalation anesthetics.
Dosage 2
- Bolus:
- 1-2 µg/kg IV bolus for sympathectomy during laryngoscopy and as a co-induciton agent.
- Analgesia during surgery:
- 0.5 to 1 µg/kg IV bolus.
- Followed by an infusion of 0.05 to 0.2 µg/kg/min.
Complications 123
- Rapid onset and high potency can lead to pronounced hypotension, bradycardia, muscle rigidity, and respiratory depression or arrest.
- Common opioid-related side effects include nausea, vomiting, pruritus, and postoperative shivering.
- Due to its rapid offset, there is a risk of postoperative hyperalgesia if not bridged with longer-acting analgesics upon discontinuation.