Michael R. Cohen, RPh, MS, ScD, FASHP

Author – Michael R. Cohen, RPh, MS, ScD, FASHP
President, Institute for Safe Medication Practices

There’s an alarming and widespread misunderstanding about insulin pens by some healthcare workers who work in hospitals: that sterility can be maintained between patients simply by affixing a fresh needle on a previously used pen. Despite numerous warnings from the Food and Drug Administration (FDA), CDC, the Institute for Safe Medication Practices (ISMP), and insulin pen manufacturers themselves, evidence continues to mount that this dangerous practice is adversely affecting thousands of patients (Read recent clinical reminder).

Just this past month we received two new reports in which a nurse knowingly used the same insulin pen for more than one patient. As is typical in these scenarios, the nurses thought the practice was acceptable if they simply changed the needle between patients and kept the same insulin pen. In one of these cases it was later determined that the original patient had human immunodeficiency virus (HIV)! Follow-up tests were being conducted on the affected patient. The nurse involved in the event reported that sharing insulin pens was routine practice at another hospital where she had worked, as long as new needles were used. In the other report, two pens were used to administer insulin to three patients in an inpatient setting, even though each pen had a patient-specific label. One of the pens was borrowed from another patient while waiting for the pharmacy to dispense one for a new patient.

Over 10 years ago, two studies suggested just how risky sharing pens between patients might be. 1, 2 One study showed that hemoglobin was detected in 6 out of 146 cartridges (4.1%) used by diabetic patients. The other study looked at pens used by 120 patients; it revealed non-inert material – including squamous cells and other epithelial cells – in 58% of cartridges. The authors noted that air bubbles can enter the cartridges after injection unless the needle is removed; suggesting that biological materials could do the same while the needle is in place.

It is true that insulin pens are convenient, preferred by patients and their doctors, and offer the possibility of improving safety when viewed from the perspective of dosing errors, particularly errors that occur when drawing the correct volume into a syringe. The dose preparation step is simpler and involves just turning a dial to the prescribed dose and affixing a special needle. However, pens were developed for use by patients, not health professionals in hospitals and long term care facilities. Leave it to us to screw it up!

Facilities using insulin pens should act immediately and provide new and temporary employee education as well as annual continuing education programs. To reduce the risk of infection in hospitals, pens should be assigned to individual patients and labeled appropriately. Alerts about risk should appear on posters in medication areas on nursing units as well as in nursing medication administration records, where insulin doses are listed. Continuous proactive risk assessment and monitoring should be considered mandatory in order to prohibit situations where an individual patient’s pen might be reused for another patient.

Unfortunately, hospitals may find these safety measures difficult to accomplish due to employee turnover and the time needed for consistent and frequent monitoring of insulin pen use by inpatients. Yet, if this cannot be done, I believe that insulin pens simply should not be used institutionally. Finally, regarding contamination of pens, despite their widespread use, there’s a dearth of evidence that these devices can be consistently used in a safe manner in hospitals. We need to step up efforts to improve safety. Improved labeling and packaging, along with more support for education of hospital workers, would be welcome steps toward the safe use of insulin pens.

For more information, please see these references:

1. Sonoki K, et al. Regurgitation of Blood into Insulin Cartridges in the Pen-like Injectors. Diabetes Care 2001; 24:603-04, available at: http://care.diabetesjournals.org/cgi/content/full/24/3/603
2. Le Floch JP, et al. Biologic Material in Needles and Cartridges After Insulin Injection with a Pen in Diabetic Patients. Diabetes Care 1998; 21:1502-04, available at: http://care.diabetesjournals.org/cgi/reprint/21/9/1502.pdf