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Improper Use of Insulin Pens

January 09, 2018

The Institute for Safe Medication Practices (ISMP) has released a safety alert about the improper use of insulin pens among patients, who are not always aware that the inner cover of a pen’s needle must be removed before administration. The confusion has resulted in patients not receiving needed doses of insulin. In fact, the alert said a patient with type 1 diabetes who did not know she was using her pen incorrectly died after she developed diabetic ketoacidosis.

Stuart T. Haines, PharmD, a professor in the department of pharmacy practice at the University of Mississippi School of Pharmacy, co-authored “Best Practices in Ensuring the Safe Use of Insulin Pen Devices in Hospitals,” a guideline published in the American Journal of Health-System Pharmacy ( We recently talked to him about the pros and cons of using pen devices to administer insulin and what providers need to know about the ISMP warning.

How can pen devices improve the administration of insulin?

There is always the potential for patient harm when insulin therapy is prescribed because of dosing errors—insulin needs to be dosed precisely and the doses that are given are highly variable among patients. The consequences of administering too much insulin are not limited to hypoglycemic symptoms like shakiness, palpitations, and sweating; patients can also become unconscious, slip into a coma, and even die in the event of a severe overdose. There’s a big push on the outpatient side of care to use pen devices, which are easier and more convenient for patients to use and improve their transition to home. Pens reduce some of the risks associated with administering insulin, including improved dosing precision that mitigates the risk of overdose, but they come with their own potential safety issues.

What are some of those associated risks?

Most practitioners are trained to administer insulin using vials and syringes, so procedurally the use of pens is slightly different. I don’t think that directly leads to patient harm. A pen typically contains 300 units of insulin, but a single dose for most patients is typically between 10 and 50 units. Because pens are multi-dose devices, providers might be tempted to administer doses to several patients from a single pen, which increases risk of infection and the transmission of bloodborne pathogens. A pen’s cartridge can harbor pathogens after administration, so changing the needle between uses is not enough to eliminate the risk of transferring pathogens between patients.

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What can be done to reduce the likelihood that a single pen is used on multiple patients?

Providers should note the patient’s name on the label and the label should be adhered to the barrel of the pens (not on the pen cap or a plastic bag). The label should have a patient-specific barcode, so the provider who is administering the insulin can scan the pen and the patient’s wristband to ensure the correct individual is not only receiving the correct insulin but also that the insulin pen device is intended for that patient. Staff must be trained on the potential risk of reusing needles and should store pens in a patient-specific drawer or location. Pens should be retrieved from the storage area before administration and returned immediately after the dose is given.

How should the ISMP warning impact the care of patients who use insulin pens?

Healthcare professionals use automated injector pen devices during inpatient care to reduce risk of accidental needlesticks. When the dose is administered, the safety needle retracts or self-destructs in some way so it’s no longer able to stick someone else after it’s withdrawn. Safety pen needles are more expensive than standard-needle pens — they cost about 4 times as much — and therefore aren’t prescribed to patients for home use after discharge. The risk of needle sticks at home is relatively low and the additional cost can’t be justified.  However, patients may become confused when they’re trained to use the safety pen needles during the hospitalization, but are given standard pens for use at home. The different pen needles have different procedures for use.  Patients should receive one-on-one instruction about the use of a pen and be given the opportunity to practice self-administering injections with the actual device and pen needles they’ll use at home.

What else can providers do to ensure pen devices are used safely and effectively?

We noted several recommendations in our published guideline. Providers should clean pens before and after each use and attach a new safety needle to the device before each administration. They should prime the pen before delivering the insulin and hold the pen against the patient’s skin for at least 5 seconds after the injection is given. After administration, they should remove the needle from the device. Computerized physician order entries should note the insulin concentration in units per milliliter. This is especially important now that several different concentrated insulins are widely available. The date, time, and results of a patient’s blood glucose measurement that was taken an appropriate time before insulin administration should be noted in electronic medical records in order to prevent administering insulin doses to patients who are hypoglycemic and it’s important to administer correctional doses to patients who are hyperglycemic.

Dan Cook

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