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Analysis of Transdermal Medication Patch Errors Uncovers a “Patchwork” of Safety Challenges

Problem: A recent cluster of error reports associated with transdermal medication patches submitted to the ISMP National Medication Errors Reporting Program (ISMP MERP) led us to look back a few years at all transdermal patch error reports submitted to the ISMP MERP to identify contributing factors and make recommendations to avoid errors with this type of drug delivery system. A transdermal patch is a medicated adhesive patch placed on intact skin to provide regular, controlled release of medication doses into the bloodstream through the skin. Transdermal patches are used to deliver a wide variety of pharmaceuticals, including medications used for smoking cessation, motion sickness, hormone replacement therapy, hormonal contraception, hypertension, angina, pain, depression, overactive bladder, and Alzheimer’s disease.

Our analysis included more than 50 reports associated with 12 different transdermal medication patches submitted to the ISMP MERP within the past 4 years. During analysis, four reports were excluded because the contributing factors were not unique to medication patch delivery systems (e.g., wrong patient). Patches most frequently involved in reported errors included fentaNYL (n = 16), cloNIDine (n = 10), scopolamine (n = 7), and estradiol (n = 6). While ISMP has repeatedly published reports of errors associated with transdermal patches, we now provide details about the error types we discovered during our recent analysis of patch errors.  

Errors in the Frequency of Patch Application or Removal

ISMP received 10 reports associated with an error in the frequency of patch application or removal. Four of these errors involved estradiol patches. Depending on the brand or formulation, estradiol patches are applied either twice a week (ALORA, DOTTI, LYLLANA, MINIVELLE, VIVELLE-DOT, generics) or once a week (CLIMARA, MENOSTAR, generics). In two of the cases, a weekly estradiol patch was prescribed, but a twice weekly formulation was dispensed with directions to apply one patch weekly, which resulted in underdoses. In another case, a physician prescribed a twice weekly estradiol patch with directions to change the patch weekly, also resulting in an underdose. In the fourth event, a prescriber ordered a twice weekly estradiol patch, but the pharmacy dispensed a weekly patch with directions to apply the patch twice weekly. Some dispensing errors continued for several refills. In some cases, the manufacturers’ outer carton did not clearly specify if the patch was to be applied weekly or twice weekly.

Three of the 10 frequency errors involved dispensing fentaNYL patches with the wrong directions for application, sometimes due to a transcription error in the pharmacy. Another error in this category involved misinterpretation of a consultant’s note to “Increase Clonidine patch to TTS-2 to mitigate ketamine side effects and help with opioid withdrawal symptoms.” A hospitalist interpreted the “TTS-2” to mean Tuesday, Thursday, and Saturday, and did not know that “TTS-2” was the nomenclature used for the 0.2 mg/24 hour CATAPRES-TTS-2 (transdermal therapeutic system) brand of cloNIDine patches, which should only be applied weekly. We also received two error reports associated with removing a patch at the wrong time—one involving the removal of a fentaNYL patch instead of a lidocaine patch after 12 hours, and the other involving the removal of a nitroglycerin patch after 24 hours instead of after 12-14 hours.

Lack of Awareness of Patches on the Patient’s Skin

ISMP received seven reports associated with practitioners failing to identify patches on the patient’s skin (which had been applied prior to admission), not removing an old patch when applying a new patch, and/or finding multiple patches on patients that had been left on longer than prescribed. Five of these events involved fentaNYL patches. In one case, two patches were found on an unexpectedly somnolent patient during rounds. In another case, three 100 mcg/hour fentaNYL patches were found on an over-sedated patient with respiratory depression. One health system reported an increase in reports of patients with an applied fentaNYL patch that was missed upon admission and not found on their skin until days later. We have also received reports of finding multiple nicotine patches and rivastigmine (EXELON) patches (used for Alzheimer’s) on patients during their admission. Because many patches are clear or beige, they might easily be missed on the skin of some patients. 

Dose Confusion Due to Labeling

ISMP received seven error reports related to confusing the dose expression on the label of scopolamine patches. In the most recent report received just last month, a pharmacy technician noticed that the dose listed on the carton and inner patch pouches of the Perrigo brand of scopolamine patches was 1 mg/3 days (Figure 1, left), which did not match the dose of 1.5 mg/3 days needed to refill an automated dispensing cabinet (ADC). The technician also checked the electronic health record, order sets, medication administration record (MAR), and an electronic drug information resource, and found that the dose was expressed as 1.5 mg/3 days in all of these technologies. On the back of the Perrigo scopolamine carton, the technician noticed that the patch actually contains 1.3 mg of scopolamine base but only delivers 1 mg over 3 days. When examining other scopolamine patch products, the technician found that many have changed to a 1 mg/3 days dose expression, while others still display the dose as 1.5 mg (Figure 1, right), even though each patch only delivers 1 mg over 3 days.

Figure 1. Scopolamine transdermal system from Perrigo (left) expresses the dose as 1 mg/3 days, while TRANSDERM SCŌP (scopolamine) from Sandoz (right) expresses the dose as 1.5 mg, although the patch delivers 1 mg over 3 days.
Figure 1. Scopolamine transdermal system from Perrigo (left) expresses the dose as 1 mg/3 days, while TRANSDERM SCŌP (scopolamine) from Sandoz (right) expresses the dose as 1.5 mg, although the patch delivers 1 mg over 3 days.

This label confusion has led to prescribing, dispensing, and administration errors. In one reported event, a prescriber ordered 1 mg of a 1.5 mg/3 days patch (0.667 of the patch), and the nurse cut off one-third of the dispensed patch before applying the other two-thirds of the patch on the patient. Scopolamine patches should not be cut. In another case, a prescriber ordered a 1.5 mg scopolamine patch for a patient, and the pharmacy dispensed 1½ patches. Serious toxic effects are possible with a scopolamine overdose.

According to the US Food and Drug Administration (FDA), transdermal scopolamine product labeling should be standardized at the nominal delivery rate of 1 mg/3 days. Based on the recent reports we received in 2021, there might be a few products that have not yet transitioned to the newer dose expression (1 mg/3 days) on container labels. Or, some products with the older label (1.5 mg) may still be in circulation.    

Inappropriate Patch Prescribing

ISMP received six reports of inappropriate prescribing of fentaNYL patches. In a July 2, 2020 newsletter article, we described three examples of fentaNYL patches inappropriately prescribed for opioid-naïve patients discharged from the emergency department (ED) to treat acute pain or due to an “allergy” to codeine that was only a minor drug intolerance. Prescribing information recommends fentaNYL patches only be used in opioid-tolerant patients for the management of pain severe enough to require daily, around-the-clock, long-term opioid treatment. Since then, we have received three more error reports associated with inappropriate prescribing of fentaNYL patches to opioid-naïve patients in long-term care (LTC) facilities. Reliance on product labeling and practitioner education alone will not do enough to solve this life-threatening problem.

Wrong Dose Dispensing Errors

ISMP received six reports of dispensing the wrong dose of patches that are available in more than one strength. We previously published one of these errors in our September 24, 2020 newsletter. An order for 50 mcg/hour fentaNYL patches included “72 hours” for the duration of patch application. The “72” was mistaken as the strength, leading to erroneous dispensing of a 75 mcg/hour instead of the intended 50 mcg/hour fentaNYL patch. Including the duration of controlled drug delivery (i.e., 72 hours) in the order and the drug description field contributed to this dispensing error. In another event, a technician filling an order for rivastigmine patches 9.5 mg/24 hour for a LTC resident prepared 13.3 mg/24 hour patches and failed to notice the error because he bypassed the usual barcode scanning process. The pharmacist verifying the product did not notice a discrepancy between the 13.3 mg/24 hour patches and the image of the 9.5 mg/24 hour patches on the computer screen and dispensed the patches. The remaining event reports did not include information regarding the primary causes of the wrong dose dispensing errors.  

Patch Cover Applied without the Medication Patch

ISMP received five reports of applying a cloNIDine patch adhesive cover directly to the skin, without first applying the cloNIDine patch. In one case, only the adhesive cover was retrieved from the carton and applied; in all other cases, the active medication patch was accidentally discarded. The errors contributed to uncontrolled blood pressure. In an FDA AdviseERR published in our March 28, 2019 newsletter, FDA described reports they had received regarding patients and caregivers who had applied only the adhesive cover to the skin. The cloNIDine transdermal system (Catapres-TTS) is packaged in a carton containing individually labeled pouches of four cloNIDine patches and four adhesive covers. Once removed from the pouches, the cloNIDine patch is a different size, shape, and color than the adhesive cover, but the patch and cover do not specify which is which. Application of the adhesive cover is optional; the cover should be applied directly over the cloNIDine patch only if the patch begins to separate from the skin.

Wrong Patch Prescribed Due to Similar Ingredients

This month, we received a report about a patch error we have not previously described. A pharmacist noticed that a hormone replacement therapy drug, COMBIPATCH (estradiol and norethindrone), had been prescribed for a 20-year-old woman. Because CombiPatch is typically used to treat vasomotor symptoms associated with menopause, the pharmacist contacted the prescriber to ask whether he had instead intended to prescribe the hormonal contraceptive patch, XULANE (ethinyl estradiol and norelgestromin), for the young woman. The prescriber confirmed that he had selected the wrong patch and prescribed the intended product, Xulane.

After a second, similar prescribing error was made, the pharmacist investigated further and found that the same error had occurred with several different prescribers. Because there are so many hormonal contraceptives with similar ingredients, most prescribers had searched for “patch” and then selected the product with ingredients consistent with a contraceptive patch. However, the only hormonal “patch” available for selection in the facility’s system was CombiPatch; “patch” was not included in the Xulane drug description and had not appeared as a choice when the prescribers searched for a “patch.”

Miscellaneous Errors

ISMP also received numerous reports of miscellaneous errors associated with patches, including a drug interaction between a cloNIDine patch and a tricyclic antidepressant; a complaint about an estradiol patch that would not adhere to the skin; two reports of patches placed on skin that was not intact; two barcode issues (now resolved); and two reports of unsecured fentaNYL patch disposal that could allow diversion, abuse, or accidental poisoning by children who might chew or stick the patches on their skin.   

Safe Practice Recommendations: Managing patients receiving medication patches can be challenging given the variety of strengths and dosing intervals. To prevent errors with patches, consider the following recommendations, many of which are specific to the unique contributing factors associated with patch errors:

Upon Admission

  • All Patches

    • Collect a medication history from each patient upon admission and at each encounter. Use scripted questions or prompts to help identify all medications and substances that may not be readily identified by patients. Specifically question patients regarding the use of any type of patch. Identify the current location of the patch and when it was applied. 

    • Perform a full skin assessment looking specifically for patches, noting that many are small in size and may either be clear or beige in color.

Patch Prescribing and Order Verification

  • All Patches

    • Verify the indication and assess the appropriateness of patch use for each patient.

    • Within electronic prescribing systems, create medication patch order sentences that include the appropriate application frequency. Consider allowing prescribers to enter certain medication patches at ONLY the appropriate application frequencies. For example, only allow entry of the frequency of fentaNYL patch application every 72 hours or every 48 hours, not every 24 hours. 

  • Specific Patches

    • Contraceptive: Include the word “patch” or “transdermal” along with the drug description for Xulane in your electronic health record and pharmacy software.

    • Estradiol: Include brand names when prescribing estradiol patches since they have different application frequencies.

    • FentaNYL: Do not include the duration of medication delivery in the patch drug description field (which could be confused as the dose). The patient’s dosing instructions should communicate the frequency of changing the patch.

    • Hormone replacement therapy: Consider requiring documentation of the indication when prescribing these patches, and/or build an alert for younger patients who are prescribed a hormone replacement therapy patch typically intended for menopausal women.

    • Opioid: Enhance clinical decision support with pain-related order sets that are specific to patients’ opioid tolerance and prevent the ordering of fentaNYL patches for opioid-naïve patients with acute pain.

    • Opioid: Default order entry systems to the lowest initial starting dose and frequency.

Patch Dispensing

  • All Patches

    • Employ barcode scanning during the dispensing process to ensure correct product selection.

    • Identify which patches on formulary can be safely cut and which cannot; share the information with nursing staff.

  • Specific Patches

    • CloNIDine: For inpatients, consider dispensing the medication patch and adhesive cover in a ziplock bag with a label explaining the two components of the product.

    • FentaNYL: Eliminate the storage of fentaNYL patches in ADCs or as unit stock in clinical locations where acute pain is primarily treated (e.g., in the ED, operating room, post-anesthesia care unit, procedural areas).

    • Opioid: Confirm the patient’s opioid status (naïve versus tolerant) prior to dispensing (and administering) patches appropriate only for opioid-tolerant patients.

    • Scopolamine: Edit prescriber and pharmacy order entry systems, order sets, and MARs to indicate the drug delivery rate of 1 mg over 3 days (Figure 2), and ensure that the labeling on patches purchased match this newer dose expression.

Figure 2. Example of one health system’s edits in the electronic health record to communicate the 1 mg over 3 days delivery of scopolamine patches.
Figure 2. Example of one health system’s edits in the electronic health record to communicate the 1 mg over 3 days delivery of scopolamine patches.

Patch Administration/Removal

  • All Patches

    • Employ barcode scanning during the administration process to ensure correct product selection.

    • On MARs, prompt for documentation of the location of all medication patches applied, and link all entries for medication patches to an order for removal at the appropriate interval.

    • Provide nurses with a documentation prompt each shift to verify placement of each medication patch and to record the location, if necessary.

    • Provide and implement secure waste disposal systems for patches containing controlled substances.

  • Specific Patches

    • CloNIDine: Consider building an MAR note to remind nurses to apply the medication patch and not just the cover. If the adhesive cover is used over the medication patch, it is best to label the adhesive cover with the drug name, strength, and date, before applying it.

Patient/Caregiver Education

  • All Patches

    • Provide verbal and written education to patients/caregivers on the use of patches (e.g., when to remove and replace the patch) and any related safety concerns and error potential; verify patient understanding. (For an ISMP fentaNYL patch consumer leaflet.)

    • Remind patients/caregivers to read the accompanying leaflet or Patient Instructions (found in the carton) before using the patches. 

    • Teach patients/caregivers to safely discard used or unneeded patches according to guidance in the prescribing information. For example, a fentaNYL patch should be disposed by folding the sticky side together and flushing it down the toilet.