Filter Needles with powdered meds?


  • Specializes in Level II & III NICU, Mother-Baby Unit. Has 21 years experience.

I know very well that the filter needles are always to be used when drawing up any medication from a glass ampule. Fully understand about microscopic glass shards and how they can cause problems.

Now I am wondering if I should be using one to draw up a reconstituted powder medication before administering it. Example: We place sterile water in (flat rubber topped) vials of powdered ampicillin and then draw up the liquid ampicillin after it has become clear and fully mixed. Once it's mixed do I need to use a filter needle to draw it up into a syringe and then remove the filter needle before connecting it to the IV medication tubing to give to the patient?

I guess my main question is: Could there be microscopic blobs of unmixed powdered ampicillin which needs to be filtered before administering? I'd love to know the correct answer and would be ridiculously happy if someone has a reference I could use to share with my coworkers if this is true. I want to do what is best for my patients and realize that new evidence occurs daily and changes can be good.

Thanks in advance for any information or thoughts you have on this subject!

Has 11 years experience.

My thoughts:

If a filter needle was necessary, it would remove blobs of medication---medication that you intended on mixing into your diluent and administer to the patient. This does not make sense because, well, the patient needs that med. If the medication is dissolving so poorly into the diluent that a filter needle is necessary, the answer is not in the needle but a major overhaul in the production or mixing of the drug.


223 Posts

Specializes in Level II & III NICU, Mother-Baby Unit. Has 21 years experience.

Thanks for your reply and thoughts! I'm thinking of microscopic amounts of undiluted powder though. The filter needle filters out particles that are 5 microns in size; actually quite microscopic. It seems like the filter would only take out the teensy microscopic bits if there were any, similar to how it removes the teensy microscopic bits of glass shards from ampules. I'd absolutely hate to think I was filtering out too much of the medication and causing the patient not to receive the full dose!!!

I guess I'm over thinking this. I only got started thinking about it when seeing a nurse draw up her reconstituted (diluted powder with sterile water) ampicillin and her saying, "I always filter medications that are powder that I've mixed up." Again, I think too much I suppose.

Thanks again for your thoughts! They are good ones! I wonder if I should ask a pharmacist?.....