The US Food and Drug Administration issued an alert to health care professionals reminding them that single-patient insulin pens and insulin cartridges should not be used to administer medication to multiple patients due to the potential risk of transmitting blood-borne pathogens such as HIV and the hepatitis viruses.

Insulin pens are pen-shaped injector devices that contain a disposable needle and either an insulin reservoir or an insulin cartridge. The devices typically contain enough insulin for a patient to self-administer several doses of insulin before the reservoir or cartridge is empty. All insulin pens are approved only for single-patient use (one device for only one patient).

The FDA is aware of incidents at two undisclosed hospitals zinvolving more than 2,000 people in which the cartridge component of the insulin pens were used to administer insulin to multiple patients, although the disposable needles were reportedly changed among patients.

"Insulin pens are designed to be safe for one patient to use one pen multiple times with a new, fresh needle for each injection," said Amy Egan, deputy director of safety at the FDA's Division of Metabolism and Endocrinology Products in the Center for Drug Evaluation and Research. "Insulin pens are not designed, and are not safe, for one pen to be used by more than one patient, even if needles are changed between patients due to the risk of transmitting blood-borne pathogens."

Patients exposed to shared insulin pens are being contacted by the two hospitals and are being offered testing for hepatitis and HIV. Some of the potentially exposed patients have reportedly tested positive for the hepatitis C virus, although it is not known if the virus was spread as a result of insulin pen sharing.

The FDA is working with the Centers for Disease Control and Prevention and professional organizations to address infection control issues related to insulin pens.