Autoinjectors and pen injectors are common devices that allow people to self-administer medicine. Autoinjectors, which already have an attached needle, provide a single dose of medicine. To inject the medicine, the device is held against the skin and a button on the opposite end of the device is pressed. A small needle automatically goes into the skin to inject the medicine. After a few seconds, the needle retracts into the device. The device is then discarded. Autoinjectors help some people overcome the hesitation with injecting themselves. A few examples of autoinjectors are listed below:
• EpiPen and Auvi-Q (both epinephrine) used to treat an allergic reaction
• Trulicity (dulaglutide) and BYDUREON BCise (exenatide) used to treat diabetes
Pen injectors are another type of device for self-administering injections, but they do not come with an attached needle. These devices typically contain more than one dose of medicine and can be reused. A new needle needs to be manually attached before each dose is administered. The needles are often sold separately. Humalog KwikPen (insulin lispro), a medicine to treat diabetes, and Forteo (teriparatide), used to treat osteoporosis, are examples of pen injectors that require purchasing separate pen needles. Some states require a prescription from a healthcare provider to purchase pen needles. Other states allow pen needles to be purchased when a prescription for medicine in a pen injector is being filled. However, it is not always clear which pen injectors come with a supply of needles and which do not. For example, “Needles not included” is clearly stated on the carton Forteo (Figure 1).
Both the US Food and Drug Administration (FDA) and ISMP have received reports of missed doses of medicine and unsafe reuse of needles when pen needles were not purchased with a pen injector. Most of these errors occurred because the person:
• Did not have pen needles to attach to the device
• Had the incorrect type of pen needle
• Reused the pen needle
• Used a syringe (with a needle) to withdraw the medicine from the device and then injected it with the syringe
Here’s what you can do: Ask your doctor or nurse about the medicine they prescribed and how to take it. When picking up the medicine, ask to speak to the pharmacist. Open the package in front of the pharmacist. Ask the pharmacist if pen needles come with the device. If pen needles are not included, ask the pharmacist to provide you with an adequate supply of needles. The pharmacist can contact your doctor if a prescription is needed. Ask the pharmacist to show you how to use the device. And then demonstrate back to the pharmacist by showing them how you will attach the needle, administer the medicine, and remove and dispose of the used needle. Never share pen injectors with friends or other family members, even when the needle has been changed. Never reuse a needle. And never withdraw the medicine from the pen injector by using a syringe.
ISMP thanks the FDA Division of Medication Assessment and Medication Errors Surveillance (DMAMES), Postmarket Medication Error Team (PMET): BarbraKaryne N. Nchinda Fobi, PharmD, MPH, CPPS, FISMP; Niloofar Rezvani, PharmD; and LCDR Zachary Oleszczuk, PharmD, MSPharm, BCGP for providing information for this article.
Advice from FDA: Topics can be found on FDA’s Consumer Health Information website at: www.ismp.org/ext/1134. Sign up for a free email subscription at: www.ismp.org/ext/262.
Published April 3, 2023
