Both fentanyl and buprenorphine are available in transdermal patch formulations. Transdermal patches administer drugs for absorption into the systemic circulation: they are not topical patches. The indication for using a patch vs enteral or parenteral application is continuous transdermal delivery of the opioid in the treatment of persistent pain in opioid -tolerant patients when other routes are not indicated.
Neither patch is intended for acute pain management, and are generally reserved for patients with persistent pain (eg: outpatient cancer pain) who are intolerant to, or not well managed with other systemic dosing forms.
Fentanyl Patches
Fentanyl patches are available from several different manufacturers using varying technologies for drug delivery.
Patches come in different sizes from 25 to 100 mcg/h, multiple patches can be used simultaneously. The patches were not designed to be cut,
Fentanyl patches are only indicated for patients who have received at least 60 oral morphine equivalents (OME) for 1 week or longer. When starting a patient on a fentanyl patch a conversion table needs to be used.
Patches may require 12-24 hours to reach steady-state release characteristics after application. Fentanyl patches are generally applied for a period of 72 hours and absorption is influenced by skin – body temperature and tissue blood flow.
Buprenorphine Patches
Buprenorphine is a partial mu receptor agonist. Buprenorphine is a potent analgesic with a reduced likelihood to cause serious opioid related adverse events such as respiratory depression. Buprenorphine is also used in the treatment of opioid use disorder (OUD).
Buprenorphine patches are similar to fentanyl patches in that they are designed to be worn for several days. Each patch is designed to delivery drug for 7 days. Patches are available in strengths of 5 mcg/hr; 7.5mcg/hr; 10 mcg/hr; 15 mcg/hr and 20 mcg/hr.
Opioid patches have the same side effects as other systemically applied opioids, including nausea, constipation, dizziness, or drowsiness - sedation.
Fentanyl patches have been associated with respiratory depression, overdose and death.
Headache and application site pruritus may also occur.
The strong adhesive may cause skin irritation in long-term users. Applying corticosteroid creams (e.g., hydrocortisone) under the patches is not recommended, as it may changes the release characteristics and transdermal penetration of the drug.