DURAGESIC-12
Clinical safety rating: caution
Comprehensive clinical and safety monograph for DURAGESIC-12 (DURAGESIC-12).
Fentanyl is a potent synthetic opioid agonist that primarily binds to mu-opioid receptors in the central nervous system, leading to analgesic effects by increasing potassium conductance and decreasing calcium influx, thereby inhibiting ascending pain pathways and altering pain perception.
| Metabolism | Fentanyl is primarily metabolized in the liver via CYP3A4-mediated N-dealkylation to norfentanyl, an inactive metabolite. Approximately 75% of the dose is excreted in urine, mainly as metabolites, with less than 10% as unchanged drug. |
| Excretion | Renal: approximately 75% as metabolites (primarily norfentanyl and other inactive metabolites) and <10% as unchanged fentanyl; fecal: approximately 9%; biliary: minor. |
| Half-life | Terminal elimination half-life is approximately 20–27 hours (range 13–44 hours) after transdermal patch removal; prolonged in elderly, hepatic impairment, and with continuous use due to drug accumulation in skin and adipose tissue. |
| Protein binding | Approximately 80–85% bound to plasma proteins, primarily albumin and α1-acid glycoprotein. |
| Volume of Distribution | Approximately 6 L/kg (range 3–8 L/kg) after intravenous administration; high Vd indicates extensive tissue distribution and accumulation in fat and muscle. |
| Bioavailability | Transdermal: approximately 92% relative to intravenous; absolute bioavailability is about 30–40% (due to first-pass metabolism, but transdermal bypasses hepatic first-pass, hence high relative bioavailability). |
| Onset of Action | Transdermal: 12–24 hours (serum levels plateau at 12–24 hours, but initial analgesia may take up to 24–48 hours to achieve steady state; onset is delayed compared to IV/IM routes). |
| Duration of Action | Transdermal: approximately 72 hours per patch; analgesic effects persist for 12–24 hours after patch removal due to continued absorption from skin depot. |
Transdermal patch, initially 12 mcg/h applied every 72 hours in opioid-naive patients; titrate based on response and tolerance.
| Dosage form | FILM, EXTENDED RELEASE |
| Renal impairment | GFR 30-89 mL/min: start at 50% of usual initial dose; GFR <30 mL/min: avoid use or start at 50% of usual dose with cautious titration. Not recommended in dialysis patients. |
| Liver impairment | Child-Pugh class A: start at 50% of usual initial dose; Child-Pugh class B: start at 25% of usual dose; Child-Pugh class C: avoid use due to extreme risk of toxicity. |
| Pediatric use | For pediatric patients aged 2-16 years currently receiving and tolerant to opioids (equivalent to at least 60 mg oral morphine/day): initial fentanyl dose (mcg/h) based on previous 24-hour opioid requirement using standard conversion; apply patch every 72 hours. For opioid-naive pediatric patients: not recommended. |
| Geriatric use | Initiate at 50% of usual adult starting dose (e.g., 12 mcg/h every 72 hours) due to increased sensitivity and reduced clearance; titrate cautiously with longer intervals between dose adjustments. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for DURAGESIC-12 (DURAGESIC-12).
| Breastfeeding | Fentanyl transfers into breast milk; M/P ratio approximately 0.17-0.47. Caution: risk of infant sedation and respiratory depression. Consider benefits vs risks; avoid if infant is <3 months or has respiratory compromise. |
| Teratogenic Risk | Pregnancy category C. First trimester: Limited data; theoretical risk of neural tube defects if folate deficiency exacerbated. Second and third trimesters: Risk of neonatal withdrawal syndrome, respiratory depression, and decreased fetal growth; avoid prolonged use near term. |
■ FDA Black Box Warning
WARNING: LIFE-THREATENING RESPIRATORY DEPRESSION; ACCIDENTAL EXPOSURE; ABUSE POTENTIAL; RISKS FROM CONCOMITANT USE WITH BENZODIAZEPINES OR OTHER CNS DEPRESSANTS; NEONATAL OPIOID WITHDRAWAL SYNDROME; RISK OF MEDICATION ERRORS; and RISK OF SERIOUS HARM OR DEATH WITH CONCOMITANT USE OF CYP3A4 INHIBITORS. DURAGESIC is contraindicated in the management of acute or intermittent pain, or in opioid-non-tolerant patients. Accidental exposure to DURAGESIC may result in fatal respiratory depression.
| Serious Effects |
["Opioid non-tolerant patients","Management of acute or intermittent pain","Postoperative pain management","Significant respiratory depression","Acute or severe bronchial asthma in an unmonitored setting or in the absence of resuscitative equipment","Known or suspected gastrointestinal obstruction, including paralytic ileus","Hypersensitivity to fentanyl or any components of the system"]
| Precautions | ["Life-threatening respiratory depression, especially during initiation or dose escalation","Accidental exposure can be fatal","Risk of abuse, misuse, and addiction","Risks from concomitant use with benzodiazepines or other CNS depressants","Neonatal opioid withdrawal syndrome with prolonged use during pregnancy","Risks of medication errors (e.g., confusion with other fentanyl products)","Serotonin syndrome with concomitant serotonergic drugs","Adrenal insufficiency","Severe hypotension","Risks in patients with head injury or increased intracranial pressure","Application site reactions and skin irritation","Wound healing complications in patients with surgical wounds"] |
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| Fetal Monitoring |
| Monitor maternal vital signs and pain scores; fetal heart rate monitoring if near term or prolonged use; assess neonatal for signs of withdrawal and respiratory depression postpartum. |
| Fertility Effects | May impair female fertility via disruption of gonadotropin-releasing hormone pulsatility leading to anovulation; male fertility impact unknown but opioid use can reduce libido and erectile function. |