July 17, 2013
We are often asked how long an injectable medication is good for once it has been punctured. This comes up with multi-dose vitamin B12, insulin, and testosterone that have a preservative to prevent bacterial growth.
Phil, Pharmacy Manager
These larger multi-dose vials may save a patient money but can be harmful if used longer than recommended. I have seen patients want to use the same vial of vitamin B12 or testosterone for several months to save money. Doing this is not safe since the medication may no longer be effective and it can lead to an infection.
The recommendation from The United States Pharmacopeia (USP) Chapter 797 says once the multi-dose vial has been punctured it is good for 28 days. This is what most manufactures follow unless they have done their own studies. For more information about this topic you can go to http://www.cdc.gov/injectionsafety/providers/provider_faqs_multivials.html.
Pharmacists at Harmons can counsel you on the safe use of these medications.