Transdermal patches are medicated adhesive patches placed on intact skin to provide regular, controlled release of medication doses into the bloodstream through the skin. They are used to deliver a wide variety of pharmaceuticals, including medications for smoking cessation, motion sickness, hormone replacement, hormonal contraception, hypertension, angina, pain, depression, overactive bladder, and Alzheimer's disease.
Over the years, error reports associated with transdermal medication patches have been submitted to the ISMP National Medication Errors Reporting Program (http://www.ismp.org/node/18107). An analysis of these reports identified factors that have contributed to these errors. Patches most frequently involved in reported errors included fentaNYL, cloNIDine, scopolamine, and estradiol. Below is a summary of the analysis with recommendations to avoid errors with transdermal patches.
Errors in the Frequency of Patch Application or Removal
Depending on the medication, the frequency of patch application or removal can vary. For example, depending on the brand, estradiol patches for menopausal symptoms are applied either twice a week (ALORA, DOTTI, LYLLANA, MINIVELLE, VIVELLE-DOT, generics) or once a week (CLIMARA, MENOSTAR, generics). An error occurred when the prescriber ordered the patch to be changed once a week, but a twice weekly estradiol patch was dispensed with directions to apply one patch weekly, resulting in underdoses. In some cases, the manufacturers' outer carton did not clearly specify if the patch was to be applied weekly or twice weekly, contributing to the confusion.
Another example of frequency errors involves fentaNYL patches, used to treat chronic pain, and typically changed every 72 hours. In some cases, the wrong directions were provided, sometimes due to a transcription error in the pharmacy. Two reported errors involved patches removed 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 12 to 14 hours.
Lack of Awareness of Patches on the Patient's Skin
Sometimes transdermal patches are difficult to find on the patient's skin. There were reports of practitioners failing to locate patches on the patient's skin that were applied prior to hospital admission and/or finding multiple patches on patients that were left on longer than prescribed. Most of these events involved fentaNYL patches. One report stated there were three 100 mcg/hr fentaNYL patches found on an oversedated patient with respiratory depression. Since many patches are clear or beige, they might not be noticed.
Inappropriate Patch Prescribing
Opioids are often inappropriately prescribed for opioid-naive patients. FentaNYL patches have been inappropriately prescribed for opioid-naive patients to treat acute pain or due to an "allergy" to codeine (that was only described as a minor drug intolerance). FentaNYL patches should only be used in opioid-tolerant patients for the management of pain severe enough to require daily, around-the-clock, long-term opioid treatment.
Wrong Dose Dispensing Errors
Wrong dose errors can occur when patches are available in more than one strength or when the duration is included in the order. For example, an order for 50 mcg/hr 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/hr instead of the intended 50 mcg/hr fentaNYL patch.
Patch Cover Applied without the Medication Patch
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 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; however, the cover should be applied directly over the cloNIDine patch if the patch begins to separate from the skin. In one case, only the adhesive cover was retrieved from the carton and applied; in other cases, the active medication patch was accidentally discarded.
Wrong Patch Prescribed Due to Similar Ingredients
Many hormonal contraceptives have similar ingredients making it challenging for prescribers to select the correct product from computer screens. In addition, a hormone replacement therapy drug, COMBIPATCH (estradiol and norethindrone), typically used to treat vasomotor symptoms associated with menopause, has ingredients like those in hormonal contraceptives which increases the risk of selecting the wrong medication.
Miscellaneous Errors
Other errors associated with patches include a drug interaction between a cloNIDine patch and a tricyclic antidepressant; a patch that would not adhere to the skin; patches placed on skin that was not intact; and unsecured fentaNYL patch disposal that could allow diversion, abuse, or accidental poisoning by children who might chew or stick the patches on their skin.
To prevent errors with patches, consider the following recommendations:
* All Patches
* Collect a medication history from each patient at each encounter. Use scripted questions/prompts to identify all medications and substances that may not be readily identified by patients. Specifically question patients about the use of any 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 and may either be clear or beige.
* Verify the indication and appropriateness of patch use.
* Before cutting a medication patch, confirm that it can safely be cut; if unsure, contact the pharmacy.
* Document the location of all medication patches applied and, if possible, link to an order for removal at the appropriate interval.
* Verify placement of each patch and record the location at each encounter.
* Provide secure waste disposal systems for patches containing controlled substances.
* Specific Patches
* Opioid: Verify and document the patient's opioid status (naive versus tolerant) and the type of pain (acute versus chronic; http://www.ismp.org/node/160).
* CloNIDine: Ensure the medication patch, not just the cover, is applied to the patient's skin. If the adhesive cover is used over the medication patch, label the adhesive cover with the drug name, strength, and date, before applying it.
* Patient/Caregiver Education
* Provide verbal and written education to patients/caregivers on the use of patches (e.g., when to remove/replace) and specific error potential; verify patient understanding. (For an ISMP fentaNYL patch consumer leaflet, visit: http://www.ismp.org/ext/653.)
* Remind patients/caregivers to read the accompanying leaflet or patient instructions (found in the carton) before using patches.
* Teach patients to safely discard used/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.