Injection Technique

NHE · Volunteer Moderator Joined: Nov 21, 2004 Posts: 771

In using the dry powdered form of Avonex, I've developed the following injection technique which is a modification of the instructions in the doctor's prescribing information which is packaged with the medication. I've discovered that if you remove all of the air from the syringe prior to the IM injection, then there will be about 65 µL which will remain in the syringe. With Avonex, this represents a loss of about 2 µg of the medication. As an alternative, I dilute the vial with 1.25 mL, and after attaching the needle, add about 4 air bubbles (roughly 200 µL of air) to the syringe after inverting it, and inject the whole lot. This method leaves only about 5 µL in the syringe and maximizes my dosage to about 32.5 µg (in this approximation I've taken into account that there are probably a few µL of fluid stuck to the side of the vial which cannot be removed). The nurse representative from Biogen did not feel that injecting a small amount of air intramuscularly would be a problem.

NHE

Jean · Posted: Mon Dec 03, 2007 3:28 am Post subject:

Although she's using the pre-filled form of Avnoex, my girlfriend was told by biogen's nurse she'd better injecting a small amount of air than loosing some Avonex in the syringe or out of the syringe by trying tu put out the bubble. So you're probably right. Smile

NHE · Volunteer Moderator Joined: Nov 21, 2004 Posts: 771

Here's another tip for anyone using the powdered form of Avonex. When you're ready to add the sterile water to the vial containing the dried Avonex, hold the vial and syringe horizontally so that the water will gently run down the side of the vial as it contacts the dried Avonex pellet. This will prevent it from dripping directly onto the pellet which can cause bubbles to form.

NHE