gasguide

Fentanyl

Sublimaze

Synthetic phenylpiperidine opioid agonist (μ)

μ-opioid receptor agonist. ~100× potency of morphine.

Indications

  • Intraop analgesia
  • Pre-induction blunting of laryngoscopy response
  • Postop pain
  • Patches for chronic pain

Dosing

ContextAdultPediatric
Induction adjunct1–3 mcg/kg IV
Intraop bolus0.5–1 mcg/kg IV q30 min
Cardiac induction5–25 mcg/kg IV
PCA10–25 mcg q5–10 min
Epidural1–2 mcg/mL infusion adjunct

Pharmacokinetics

Onset 1–2 min. Duration 30–60 min (bolus). Context-sensitive half-time ↑ with prolonged infusion.

Hemodynamic effects

Minimal at typical doses. Bradycardia at high doses.

Respiratory effects

Dose-dependent respiratory depression. Chest wall rigidity at rapid high doses (treat with NMBA).

Side effects

  • !Respiratory depression
  • !Pruritus
  • !Nausea
  • !Constipation
  • !Tolerance + opioid-induced hyperalgesia at high cumulative doses

Contraindications

  • ×MAOI use within 14 days (relative)

Clinical pearls

  • Multimodal analgesia (acetaminophen, NSAID, regional, ketamine) reduces fentanyl needs and OIH.
  • Watch for 'fentanyl chest wall' rigidity — usually with ≥ 5 mcg/kg push.
Education only — confirm against current package inserts and institutional protocols. Doses assume normal organ function unless otherwise noted.