Fentanyl is a synthetic opioid that is used for the treatment of acute or chronic, severe pain. Fentanyl is 50 to 100 times more potent than morphine and is used only when other forms of treatment do not provide adequate analgesia. Fentanyl is indicated for use only in patients who are not responsive to the analgesic effects of other opioids, perhaps due to having developed a tolerance to other opioids.

Fentanyl delivered by oral or intravenous routes is used for the treatment of acute pain, whereas transdermal fentanyl patches are indicated for chronic pain that requires around-the-clock opioid treatment. Transdermal fentanyl patches are applied to the skin and are designed for gradual delivery of fentanyl in fixed doses. However, fentanyl has high abuse potential, and transdermal patches may be misused for their euphoric effects. Fentanyl is a very potent opioid and can cause a fatal overdose. Being aware of the risks of using a fentanyl patch can help to prevent an overdose or addiction.

What is a Fentanyl Patch?

A fentanyl patch is a delivery system used to administer fentanyl in a rate-controlled manner for 72 hours. Transdermal fentanyl patches are indicated for the management of chronic pain only in individuals who have developed tolerance to other opioids and require continuous opioid therapy. The transdermal fentanyl patch is a transparent, rectangular unit that has a fentanyl reservoir sandwiched between an adhesive layer and a backing layer. The layer that adheres to the skin has a silicone adhesive, whereas the outermost backing layer is made of polyester. A polymer membrane between the fentanyl reservoir and the adhesive layer controls the rate of fentanyl release from the reservoir.

The patch is applied to the skin, and fentanyl, being lipid-soluble, is able to permeate the skin and is gradually released in the general circulation. The fentanyl patch may be applied to any fleshy region of the body, such as the chest, back, flank, or upper limbs. The skin surface must be cleaned only with water (without soap or alcohol) before the application of the patch. The patch is replaced every 72 hours, and the new patch must be applied over a different part of the skin

Fentanyl Patch Doses

The dose of fentanyl tends to vary according to the size of the transdermal patch. A 10 cm2 patch of fentanyl delivers 25 micrograms (mcg) of fentanyl per hour. Patches are available in various sizes that deliver 12, 25, 50, 75 or 100 micrograms of fentanyl per hour. The total fentanyl content in the aforementioned variants ranges from 1.25 mg (12mcg/hr) to 10mg (100mcg/hr).

How is the Fentanyl Patch Abused?

Fentanyl is an opioid with a high potential for abuse that is abused for its ability to produce an intense euphoric high. Transdermal fentanyl patches may be abused by using multiple skin patches or directly chewing or smoking the patches. Alternatively, fentanyl may be extracted by removing the gel present in the skin patches and subsequently injected intravenously, smoked or ingested. Transdermal fentanyl patches may also be frozen and placed in the oral cavity after cutting the patch into pieces.

Fentanyl Patch Interactions

Fentanyl can interact with commonly used medications to produce life-threatening consequences, and one must inform the physician regarding the use of other medicines before the onset of fentanyl use. The use of central nervous depressants that slow down brain activity, similar to opioids, must be avoided while using fentanyl patches. Simultaneous use of central nervous system depressants like benzodiazepines, sedatives or alcohol can result in profound sedation, low blood pressure, respiratory depression, coma, and death.

Fentanyl is metabolized by liver enzymes belonging to the cytochrome family, and medications that interact with the activity of these enzymes must be avoided. Certain drugs may either increase or decrease the activity of cytochrome enzymes resulting in elevated or decreased blood fentanyl levels. This can result in either an overdose due to elevated fentanyl levels or withdrawal symptoms. Some examples of medications that influence fentanyl levels through their action on cytochrome enzymes include certain antifungal, antibiotics, anti-seizure drugs, blood pressure medications, and antidepressants. Besides these medications, alcohol and grapefruit should also be avoided while using fentanyl.

Besides these interactions, it is also important to be aware that the rate of diffusion of fentanyl from the skin patch is sensitive to changes in temperature. Patients using transdermal fentanyl should avoid the patch from getting directly exposed to heat sources such as a heating pad, hot tubs, saunas, or tanning beds. Even elevated body temperature due to intense exercise or fever can result in increased diffusion of the drug. Increased diffusion of the drug due to exposure to heat sources or elevated body temperature can result in side effects and may even result in death.

Side Effects of Fentanyl Patch

The most commonly observed adverse effects of fentanyl include constipation and nausea. Other side effects of fentanyl include:

  • Fentanyl Patch Side Effects





    Abdominal pain




    Difficulty urinating

    Low blood pressure

    Slow or shallow breathing

Long-term use of fentanyl can lead to the development of dependence on the drug. The physical dependence on fentanyl involves a need to use the drug to function normally. Such dependence develops even when fentanyl is used as prescribed. However, misuse or abuse of fentanyl can lead to an addiction to the drug. Addiction to fentanyl is characterized by an inability to control drug use despite negative consequences on social and work life.

Fentanyl Patch Withdrawal

Transdermal fentanyl patches are used for the treatment of chronic pain and may involve prolonged use of the medication. This results in the development of dependence on fentanyl, and subsequent discontinuation of fentanyl use can cause severe withdrawal symptoms. These withdrawal symptoms may emerge even after a reduction in the dose of fentanyl. Although not life-threatening, these symptoms can be very unpleasant and can lead to a relapse. The symptoms of fentanyl withdrawal include restlessness, anxiety, agitation, insomnia, diarrhea, vomiting, nausea, muscle and bone pain.

When dependence on transdermal fentanyl occurs due to prolonged use of the patches as prescribed, the withdrawal symptoms emerge 18-48 hours after discontinuation of fentanyl use. Transdermal fentanyl has a long half-life of 17 hours, and this may result in a longer withdrawal period of 10-20 days relative to other opioids with a shorter half-life (4-10 days).

Fentanyl Patch Overdose

Fentanyl is about 50 times more potent than heroin, and hence, the abuse of fentanyl can easily result in an overdose. Furthermore, the lack of adequate care while using fentanyl patches or using certain medications that interact with fentanyl can result in an accidental overdose. An overdose may also occur in a clinical setting when the transition is made from treatment with a weaker opioid to fentanyl. Overestimation of the dose of fentanyl during the initiation of fentanyl treatment can cause an overdose.

Some of the signs of a fentanyl overdose include:

  • Symptoms of Fentanyl Overdose

    Respiratory depression involving slow or shallow breathing

    Pinpoint or constricted pupils

    Reduced or loss of consciousness

    Low body temperature

    Clammy skin

    Loss of muscle tone characterized by the body becoming limp

    Low blood pressure

    Fingertips and lips may turn bluish or purple

Signs of Fentanyl Abuse

Fentanyl can produce an intense euphoric high and, thus, has a high potential for abuse.

Related Topic: Fentanyl Overdose

Some of the common signs of fentanyl abuse include:

  • Fentanyl Abuse Signs



    Weight loss


    Mood swings


    Changes in sleep patterns

    Deficits in decision making

    Reduced sex drive

    Borrowing money without a reasonable explanation

    Stealing money to obtain the drug

Misuse or abuse of fentanyl can lead to the development of addiction to the drug over time. In addition to the signs of abuse, addiction to fentanyl is also characterized by signs such as:

  • Fentanyl Addiction Signs

    Inability to control the amount or the frequency of drug use

    Continuing drug use despite negative consequences on social and occupational functioning

    Favoring drug-related activities over recreational, social and work-related activities

    Spending a considerable amount of time obtaining, using and recovering from fentanyl intake

    Development of physical dependence on fentanyl, characterized by the need to use the drug to function normally

    Development of withdrawal symptoms after discontinuation of fentanyl use

    Development of tolerance on fentanyl, characterized by the need to use greater amounts of fentanyl to achieve the previously experienced effects.

If you or a loved one are dependent on or are addicted to prescription opioids like fentanyl, The Recovery Village Palm Beach at Baptist Health can help. The Recovery Village Palm Beach at Baptist Health provides evidence-based detoxification and rehabilitation services for substance use disorders delivered by experienced and accredited professionals.

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