Fentanyl

What it is and how it works

Mechanism of Action Fentanyl is an opioid agonist. Fentanyl interacts predominately with the opioid mu-receptor. These mu-binding sites are distributed in the human brain, spinal cord, and other tissues.

Mechanism class: Full Opioid Agonists

Indications

Fentanyl transdermal system is indicated for the management of severe and persistent pain in opioid tolerant patients, that requires an opioid analgesic and that cannot be adequately treated with alternative options, including immediate-release opioids. Patients considered opioid-tolerant are those who are taking, for one week or longer, at least 60 mg morphine per day, 25 mcg transdermal fentanyl per hour, 30 mg oral oxycodone per day, 8 mg oral hydromorphone per day, 25 mg oral oxymorphone per day, 60 mg oral hydrocodone per day, or an equianalgesic dose of another opioid. Limitations of Use: • Because of the risks of addiction, abuse, misuse, overdose, and death, which can occur at any dosage or duration and persist over the course of therapy , reserve opioid analgesics, including fentanyl transdermal system for use in patients for whom alternative treatment options are ineffective, not tolerated or would be otherwise inadequate to provide sufficient management of pain. • Fentanyl transdermal system is not indicated as an as-needed (prn) analgesic.

Dosage and administration (summary)

• Fentanyl transdermal system should be prescribed only by healthcare providers who are knowledgeable about the use of extended-release/long-acting opioids and how to mitigate the associated risks. • Use the lowest effective dosage for the shortest duration of time consistent with individual patient treatment goals. Reserve titration to higher doses of fentanyl transdermal system for patients in whom lower doses are insufficiently effective and in whom the expected benefits of using a higher dose opioid clearly outweigh the substantial risks.

Contraindications

Fentanyl transdermal system is contraindicated in: • patients who are not opioid-tolerant. • the management of acute or intermittent pain, or in patients who require opioid analgesia for a short period of time. • the management of post-operative pain, including use after out-patient or day surgeries, (e.g., tonsillectomies). • the management of mild pain. • patients with significant respiratory depression .

Warnings and precautions

• Risk of Increased Fentanyl Absorption with Elevated Body Temperature : Regularly evaluate patients with fever closely for sedation and respiratory depression and reduce the dose if necessary. Warn patients to avoid strenuous exertion that may lead to increased body temperature. • Opioid Induced Hyperalgesia (OIH) and Allodynia : Opioid-Induced Hyperalgesia (OIH) occurs when an opioid analgesic paradoxically causes an increase in pain, or an increase in sensitivity to pain.

Pregnancy

Pregnancy Risk Summary Use of opioid analgesics for an extended period of time during pregnancy may cause neonatal opioid withdrawal syndrome . Available data with fentanyl transdermal system in pregnant women are insufficient to inform a drug-associated risk for major birth defects and miscarriage.

Storage and supply

Fentanyl Transdermal System is supplied in cartons containing 5 individually packaged systems and is available as 12 mcg/hour*, 25 mcg/hour, 37.5 mcg/hour, 50 mcg/hour, 62.5 mcg/hour, 75 mcg/hour, 87.5 mcg/hour or 100 mcg/hour of fentanyl. The 12 mcg/hour* transdermal system is 3.13 cm 2 and contains 1.28 mg fentanyl.

Source: Fentanyl (Fentanyl) — US FDA prescribing information, 2025-12-15, DailyMed. Summarised and shortened; the full label governs. Iranian registration, indications and labelling may differ.