CLASS: Narcotic agonist/narcotic analgesic

Mechanism of Action:

Alleviates pain by acting on the pain receptors in the brain; elevates pain threshold. Depresses central nervous system; depresses brainstem respiratory centers; decreases responsiveness to changes in PaC02. Increases venous capacitance (venous pooling) and vasodilates arterioles thereby reducing preload and afterload.

Indications and Field Use:

Analgesia, especially in patients with burns or other trauma, myocardial infarction, renal colic.
Adjunct to sedation in post-intubation state.
Adjunct to induction in Rapid Sequence Intubation (RSI) or medication assisted intubation.


Known allergy or intolerance to drug (assess for medic alert bracelet) Respiratory depression if airway and breathing can’t be supported Known elevated intracranial pressure e.g. mass lesion
Head injury with ALOC (relative)

Asthma (relative) Abdominal pain (relative)

Adverse Reactions:

MS: Muscle rigidity, particularly involving muscles of respiration.
CV: Bradydysrhythmias (common) or tachydysrhythmias, hypotension, orthostatic hypotension.

Resp: Respiratory depression (common) or arrest.
CNS: Excess sedation, seizures leading to coma and arrest, pupillary constriction, dizziness, blurred vision. GI: Nausea and vomiting.

Derm: Histamine release may cause local or generalized urticaria. Diaphoresis. 



CNS, Respiratory and to a certain extent CV side effects can be reversed by naloxone. This does not preclude the aggressive support of airway, ventilation and circulation prior to the administration of naloxone if the clinical situation dictates.

Adult Dosage:

IV/IO Dose: Administer 25-50 mcg (0.5 – 1.0 mL of 50mcg/mL concentration) increments slow IV push (over 1-5 minutes) until desired effect. Consider the lower dose in the elderly, debilitated, or those with chronic lung disease. Onset of analgesic action almost immediate, duration of analgesic action 30-60 minutes.

IM Dose: Same as IV/IO dose. Onset of analgesic action seven to eight minutes, duration of analgesic action one to two hours.

IN Dose: 25-50 mcg
Total Dose: Not to exceed 200 mcg

(Note: Duration of respiratory depressant effect of fentanyl may be longer than analgesic effect.)

Pediatric Dosage (12 months ≤ 17 years):

IV/IO Dose: 1-2 mcg/kg (0.04-0.06 mL/kg of 50mcg/mg concentration) slow IV/IO push.

IM Dose: Same as IV/IO dose.

IN Dose: 1-2mcg/kg

Total Dose: Not to exceed 50 mcg, Q1hr prn

(Note: Patch for on-line medical direction if Fentanyl citrate use is considered in children <2 or if additional doses are needed.)

Routes of Administration: 

Usually given IV/IO in the field, can be given IM or IN.

Peak Effects:

Within 5-15 minutes when given IV/IO/IN. Less predictable when given IM. Peak respiratory depressant effect within 5-15 minutes after onset of analgesic effect.

Dosage Forms/Packaging: 

100 microgram/2 mL ampules or 250 micrograms/5 mL ampules

Arizona Drug Box Minimum Supply:

Paramedic: 200 micrograms Intermediate: Same as paramedic supply 

© Matt Dillard 2012