Hospira is voluntarily recalling two lots of naloxone hydrochloride injection, used to treat opioid overdoses, because they may contain particulate matter on the syringe plunger, the Food and Drug Administration announced yesterday. The lots were distributed to hospitals, wholesalers and others in the United States, Puerto Rico and Guam. The company has notified hospitals and others to arrange for return of the recalled product, which should not be used or distributed. Adverse reactions or quality problems associated with the products may be reported to the FDA's MedWatch program. No adverse events have been reported to date.