remifentanil

Brand: Ultiva

⚠ BBW ISMP High Alert Prototype: morphine
Drug Class: opioid analgesic
Drug Family: opioid
Subclass: ultra-short-acting mu-opioid agonist
Organ Systems: cns

Mechanism of Action

Potent, selective mu-opioid agonist with a unique ester linkage in its structure that is hydrolyzed by nonspecific blood and tissue esterases, producing an ultra-short duration of action independent of hepatic or renal function — context-sensitive half-time remains constant regardless of infusion duration.

mu-opioid receptor (MOR)

Indications

  • induction and maintenance of general anesthesia
  • analgesia in mechanically ventilated ICU patients (short-term)
  • procedural sedation/analgesia

Contraindications

  • epidural or intrathecal administration (formulation contains glycine, a neurotoxin)
  • use as sole anesthetic (without consciousness-ablating agent)

Adverse Effects

Common

  • apnea
  • respiratory depression
  • hypotension
  • bradycardia
  • muscle rigidity (chest wall rigidity at high doses)

Serious

  • respiratory arrest without mechanical ventilation support
  • opioid-induced hyperalgesia (with prolonged use)
  • acute opioid tolerance

Pharmacokinetics (ADME)

Absorption IV only; no oral formulation
Distribution protein binding ~70%; Vd ~0.35 L/kg
Metabolism ester hydrolysis by nonspecific blood and tissue esterases; independent of liver and kidney function
Excretion primarily renal (as inactive metabolites)
Half-life 3-10 minutes (context-sensitive half-time constant at 3-4 minutes regardless of infusion duration)
Onset 30-60 seconds IV
Peak 1-3 minutes
Duration 5-10 minutes (offset driven by metabolism, not distribution)
Protein Binding 70%
Vd 0.35 L/kg

Drug Interactions

Drug / Agent Mechanism Severity
CNS depressants (propofol, benzodiazepines) synergistic respiratory depression; dose reduction of both required major
volatile anesthetics synergistic anesthetic and respiratory depression major

Nursing Considerations

  1. Remifentanil must only be administered in settings with full resuscitation capabilities (mechanical ventilation, naloxone, crash cart); never administer without these resources immediately available.
  2. The ultra-short duration means analgesia terminates abruptly within 5-10 minutes of stopping the infusion; transition to alternative analgesia before discontinuation to avoid uncontrolled pain.
  3. Chest wall rigidity ('wooden chest') at high infusion rates can impede ventilation and must be managed with succinylcholine or rocuronium.
  4. Do not dilute in or administer with lactated Ringer's solution — incompatible; use normal saline or D5W for dilution.

Clinical Pearls

  • Remifentanil is the only opioid whose pharmacokinetics are independent of organ function; because plasma esterases metabolize it, its elimination is unaffected by hepatic or renal failure.
  • The clinical consequence of remifentanil's ultra-short action is that analgesia ends abruptly upon discontinuation — failure to pre-emptively establish alternative analgesia (multimodal or longer-acting opioid) results in severe acute pain.

Safety Profile

Pregnancy use-with-caution
Lactation use-with-caution
Renal Adjustment Not required
Hepatic Adjustment Not required
TDM Not required