A study has found that epinephrine auto-injectors may have a longer shelf life than expected. More than double in some cases. Doctors are cautious, but further study could change the expiration date on many existing and new epi-injectors.
The study looked at expired epinephrine auto-injectors, but only included 40 units, so critics say it is not yet conclusive. The findings were interesting, though, and will likely lead to further study as the cost of EpiPens and other units have become very high.
Some units that were 50 months past expiration on the label were still viable.
After 29 months past expiration: The study found that the auto-injectors tested had at least 90 percent of their stated amount of epinephrine still intact.
After 50 months past expiration: 84 to 88 percent of the stated epinephrine was still present.
After 30 months past expiration: EpiPen Jr units had 88 percent viability of epinephrine.
The study was conducted by a team lead by researcher Lee Cantrell, a professor of medicine and pharmacy at the University of California, San Diego. Cantrell's wife is a pediatrician and commented that she hears questions about the shelf life of EpiPens regularly.
Last year, Mylan had conducted an internal study on the EpiPen and had findings that prompted them to ask the Food and Drug Administration to allow them to extend the shelf life from 18 months to 24 months. The company expected that new shelf life to be offered sometime this year.
Several experts, including Cantrell who authored the study, caution parents and patients to refill their auto-injectors to keep expiration dates current until further study has been done.