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
| Context | Adult | Pediatric |
|---|---|---|
| Induction adjunct | 1–3 mcg/kg IV | 1–3 mcg/kg IV (full-term + older) |
| Intraop bolus | 0.5–1 mcg/kg IV q30 min | 0.5–1 mcg/kg IV q30 min |
| Cardiac induction | 5–25 mcg/kg IV | 5–25 mcg/kg IV (peds cardiac) |
| PCA | 10–25 mcg q5–10 min | 0.25–0.5 mcg/kg q10–15 min (age-appropriate) |
| Epidural | 1–2 mcg/mL infusion adjunct | — |
| Continuous infusion (NICU/PICU) | — | 0.5–2 mcg/kg/hr (neonates: 0.5–1 mcg/kg/hr; older: up to 2) |
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.
📊 Related teaching panels
Standalone diagrams matched to this topic.
Other drugs in Narcotics & Analgesics
- Remifentanil
μ-opioid agonist. Ester linkage hydrolyzed by nonspecific tissue + plasma esterases — no organ-dependent clearance.
- Ketorolac
Inhibits cyclooxygenase → ↓ prostaglandin synthesis → anti-inflammatory + analgesic + antipyretic.
- IV Acetaminophen
Central COX inhibition + endocannabinoid + descending serotonergic modulation. Minimal peripheral COX → no NSAID-like GI/renal/platelet effects.
Browse all classes: /reference/drugs