Fentanyl transdermal systems are intended for transdermal use (on intact skin) only. Do not use a fentanyl transdermal system if the pouch seal is broken or the patch is cut, damaged, or changed in any way.

The safety of fentanyl transdermal system has not been established in children under 2 years of age. Fentanyl transdermal system should be administered to children only if they are opioid-tolerant and 2 years of age or older (see PRECAUTIONS, Pediatric Use).

Fentanyl transdermal system is ONLY for use in patients who are already tolerant to opioid therapy of comparable potency. Use in non-opioid tolerant patients may lead to fatal respiratory depression. Overestimating the fentanyl transdermal system dose when converting patients from another opioid medication can result in fatal overdose with the first dose. The mean half-life is approximately 17 hours. Therefore, patients who have experienced serious adverse events, including overdose, will require monitoring for at least 24 hours after fentanyl transdermal system removal since serum fentanyl concentrations decline gradually and reach an approximate 50% reduction in serum concentrations 17 hours after system removal. 

Fentanyl transdermal system should be prescribed only by persons knowledgeable in the continuous administration of potent opioids, in the management of patients receiving potent opioids for treatment of pain, and in the detection and management of hypoventilation including the use of opioid antagonists. 

All patients and their caregivers should be advised to avoid exposing the fentanyl transdermal system application site and surrounding area to direct external heat sources, such as heating pads or electric blankets, heat or tanning lamps, saunas, hot tubs, and heated water beds, etc., while wearing the system. Patients should be advised against taking hot baths or sunbathing. There is a potential for temperature-dependent increases in fentanyl released from the system resulting in possible overdose and death. A clinical pharmacology trial conducted in healthy adult subjects has shown that the application of heat over the fentanyl transdermal system increased mean fentanyl AUC values by 120% and mean Cmax values by 61%.

Based on a pharmacokinetic model, serum fentanyl concentrations could theoretically increase by approximately one-third for patients with a body temperature of 40°C (104°F) due to temperature-dependent increases in fentanyl released from the system and increased skin permeability. Patients wearing fentanyl transdermal systems who develop fever or increased core body temperature due to strenuous exertion should be monitored for opioid side effects and the fentanyl transdermal system dose should be adjusted if necessary.

Death and other serious medical problems have occurred when people were accidentally exposed to fentanyl transdermal system. Examples of accidental exposure include transfer of a fentanyl transdermal system from an adult’s body to a child while hugging, accidental sitting on a patch and possible accidental exposure of a caregiver’s skin to the medication in the patch while the caregiver was applying or removing the patch. 

Placing fentanyl transdermal system in the mouth, chewing it, swallowing it, or using it in ways other than indicated may cause choking or overdose that could result in death.