Fentanyl, Duragesic®

Brand name

  • Duragesic®

Drug Class

  • Opioid Analgesic 
  • Anilidopiperidine
  • General Anesthetic


  • Patches: 12.5 mcg/hr, 25 mcg/hr, 50 mcg/hr, 75 mcg/hr.


  • Patches are used for chronic pain management
  • Intravenous fentanyl is often used for anesthesia and analgesia
  • For the treatment of break through pain in cancer patients


  • Fentanyl is approximately 80 to 100 times more potent than morphine and roughly 40 to 50 times more potent than pharmaceutical grade (100% pure) heroin.
  • It is a strong μ-receptors agonist


  • Substrate of CYP3A4 (major)
  • Inhibits CYP3A4 (weak)
  • Fentanyl is metabolized primarily via human cytochrome P450 3A4 isoenzyme system
  • Elimination is mainly from kidneys
  • approximately 75% of the administered dose is excreted in urine within 72 hours, mostly as metabolites with less than 10% representing unchanged drug.
  • Half life: 7 hours (range 3-12)


Pain management:


  • Bolus at start of infusion: 1-2 mcg/kg
  • Continuous infusion rate: 1-2 mcg/kg per hour


  • Initial dosage is generally 12.5 to 25 mcg/hr.
  • If currently receiving opiates, convert dosage to Fentanyl equivalents and administer an equipotent dose.
  • The transdermal system should be pressed firmly in place with the palm of the hand for 30 seconds, making sure the contact is complete, especially around the edges.
  • Each patch is to be worn for 72 hours.
  • If continued analgesia is required, a different system should be placed to a different area of skin after removal of the previous transdermal system.

Drug Interactions

  • When administered IV, fentanyl decreases clearance of Midazolam
  • Drugs that are substrates of P450 3A4 could affect the hepatic metabolism of fentanyl

Adverse Effects


  • Cardiovascular: Bradycardia, edema
  • Central nervous system: CNS depression, confusion, dizziness, drowsiness, fatigue, headache, sedation
  • Endocrine & metabolic: Dehydration
  • Gastrointestinal: Constipation, nausea, vomiting, xerostomia
  • Local: Application-site reaction erythema
  • Neuromuscular & skeletal: Chest wall rigidity (high dose I.V.), muscle rigidity, weakness
  • Ocular: Miosis
  • Respiratory: Dyspnea, respiratory depression
  • Miscellaneous: Diaphoresis

1% to 10%:

  • Cardiovascular: Cardiac arrhythmia, chest pain, DVT, flushing, hyper-/hypotension, orthostatic hypotension, pallor, palpitation, peripheral edema, syncope, tachycardia, vasodilation
  • Central nervous system: Abnormal dreams, abnormal thinking, agitation, amnesia, anxiety, attention disturbance, DVT, depression, dysphoria, euphoria, fever, hallucinations, hypoesthesia, insomnia, lethargy, malaise, mental status change, migraine, nervousness, paranoid reaction, somnolence, stupor, vertigo
  • Dermatologic: Alopecia, bruising, cellulitis, erythema, hyperhidrosis, papules, pruritus, rash
  • Endocrine & metabolic: Breast pain, hot flashes, hyper-/hypocalcemia, hyper-/hypoglycemia, hypoalbuminemia, hypokalemia, hypomagnesemia
  • Gastrointestinal: Abdominal pain, abnormal taste, anorexia, appetite decreased, biliary tract spasm, diarrhea, dyspepsia, dysphagia (buccal tablet/film), flatulence, GI hemorrhage, gingival pain (buccal tablet), gingivitis (lozenge), glossitis (lozenge), ileus, intestinal obstruction (buccal film), periodontal abscess (lozenge/buccal tablet), stomatitis (lozenge/buccal tablet/sublingual tablet), tongue disorder (sublingual tablet), ulceration (gingival, lip, mouth; transmucosal use), weight loss
  • Genitourinary: Dysuria, erectile dysfunction, urinary incontinence, urinary retention, vaginitis, vaginal hemorrhage
  • Hematologic: Anemia, leukopenia, neutropenia, thrombocytopenia
  • Hepatic: Ascites, jaundice
  • Local: Application site pain, application site irritation
  • Neuromuscular & skeletal: Abnormal coordination, abnormal gait, arthralgia, back pain, myalgia, neuropathy, paresthesia, rigors, tremor
  • Ocular: Blurred vision, diplopia
  • Renal: Renal failure
  • Respiratory: Apnea, asthma, bronchitis, cough, epistaxis, hemoptysis, hypoventilation, hypoxia, nasopharyngitis, pharyngolaryngeal pain, pharyngitis, pneumonia, rhinitis, sinusitis, upper respiratory infection, wheezing
  • Miscellaneous: Flu-like syndrome, hiccups, hypersensitivity, lymphadenopathy, night sweats, parosmia, speech disorder, withdrawal syndrome


  • Hypersensitivity to fentanyl or any component of the formulation
  • Severe respiratory disease or depression including acute asthma, unless patient is mechanically ventilated
  • paralytic ileus
  • patients requiring short-term therapy
  • management of intermittent pain
  • management of acute or postoperative pain including headache, migraine, dental pain, or use in emergency room, and in patients who are not opioid tolerant

Pregnancy and Breastfeeding

  • Teratogenic effects were not observed; however, embryo and fetotoxicity were noted in animal studies. Fentanyl crosses the placenta and the injectable formulation has been used safely during labor.
  • Enters breast milk/not recommended.


  • Healthcare professionals are reminded that dose conversion guidelines are used to convert adult patients with chronic pain from oral or parenteral opioids to FTS only and should not be used to convert FTS to other opioids due to risks of overdose and toxicity.


This document is prepared by the “Mental Health for All” team. This document is provided for information purposes only and does not necessarily represent endorsement by or an official position of the Essentials of Medicine. Advice on the treatment or care of an individual patient should be obtained through consultation with a physician who has examined that patient or is familiar with that patient’s medical history.

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