- Fentanyl is a highly potent synthetic opioid.
- One fentanyl 100mcg / hour transdermal patch applied every 3 days is the equivalent of 300mg of morphine orally daily.
- Fentanyl can be extracted from patches and misused.
- The risk of drug dependence on fentanyl patches is high.
- Prescribers should carefully establish genuine need before prescribing.
Fentanyl misuse is an emerging problem
Use of fentanyl transdermal patches carries a number of risks of overdose, with a small margin between an appropriate therapeutic dose and a toxic dose. Use of fentanyl patches requires care when commencing treatment and is only appropriate in patients in whom opioid analgesic treatment is well established. Use in opioid naïve patients is rarely if ever/never justified. It is recommended that a patient’s drug and alcohol history is assessed before any opioid is prescribed.
When fentanyl transdermal patches are used appropriately, plasma levels may take around 24 hours to reach a steady state. Fentanyl patches are designed to provide a steady release of fentanyl over 72 hours. There is no advantage in prescribing fentanyl patches to be applied daily or every two days.
Fentanyl patches may be dangerous if heat is applied to them or accidentally attached to an opioid naïve adult patient or a child. The risk of drug dependence is high when using fentanyl patches.
Fentanyl in all forms of presentation is a Schedule 8 controlled drug throughout Australia. Depending on the brand, fentanyl 100mcg / hour patches may contain up to 16.8mg of fentanyl. Significant quantities of fentanyl remain in the patches after the 72 hours transdermal application of the patch has expired.
Misuse of fentanyl patches
A number of deaths have been associated with the misuse of fentanyl patches, including multiple patches applied for an intoxicating effect and the injection of fentanyl extracted from fentanyl patches.
Fentanyl patches have a high illicit value and are subject to trafficking. In Australia the main source of fentanyl patches used illicitly is from those obtained on prescription.
Injection of fentanyl extracted from patches has resulted in a number of overdoses, including fatal overdoses. Serious injury from the injection of fentanyl extracted from patches includes ischaemic limb injury and amputation, thrombophlebitis and severe skin ulceration. Other serious consequences, common with injecting drug use include endocarditis, septic emboli and osteomyelitis.
Recommended action by prescribers
Check the patient
- Check the identity, using photo ID if possible, of any patient presenting and requesting a prescription for an opioid, including fentanyl transdermal patches.
- Establish by history and examination a genuine need for the opioid sought and decide on the best pain management plan for the individual.
- Assess drug and alcohol use, and examine the patient for evidence of injecting drug use. Arms can be inspected when checking blood pressure, and other common sites (groin, legs or neck) can be checked in the course of a full examination.
- Generally the long term prescribing of a Schedule 8 opioid exceeding an oral morphine equivalent daily dose (OMEDD) of 60mg daily should be in accord with the written support of an appropriate specialist physician, such as a pain specialist, and in accordance with a clearly documented therapeutic plan.
- Take a ‘universal precautions’ approach by routinely using the above precautions with all patients, and if necessary explaining that this is recommended best practice.
Check the previous prescribing history
- If the patient is an ‘inherited’ patient (seeking continuation of established prescribing), seek independent verification of the purported previous prescriber. If not possible, check with the purported pharmacy where the opioid is usually dispensed.
- If it is not possible to contact the previous prescriber or pharmacist, consider whether the request may be fraudulent.
- Information about the patient may be available by contacting the Ministry of Health’s Pharmaceutical Regulatory Unit by telephoning (02) 93919944.
- Information about the patient may also be available by contacting the Australian Government’s Prescription Shopping Information Service by telephoning 1800 631 181 (available 24 hours, 7 days).
Know the rules
- In NSW, if the patient is considered to be drug dependent, even if a legitimate pain condition exists, it is necessary to apply for an authority prior to prescribing for an individual patient under the requirements of the Poisons and Therapeutic Goods Act. An Application form is available online.
- Be aware that these medications are abused, diverted and injected and that successful drug seekers may not be easily identified as drug misusers.
- When fentanyl transdermal patches are prescribed, patients and carers should be advised to fold used patches so that the adhesive side of the patch adheres to itself, before wrapping and disposing of them carefully.
- There is no obligation to prescribe fentanyl patches if the prescriber is uneasy about it.