Half dose of Imitrex

Why and how to inject a half-dose of Imitrex SC ®?

Warning: This works well for some people but is to be tested for you. We cannot give any guarantee as to the effectiveness of a half-dose in a patient.

Imitrex SC ® problems:

  • Imitrex ® is not really good for your cardiovascular health. It causes vasoconstriction, i. e. a decrease of the diameter of the arteries leading to a decrease in blood flow. Watch out for people with high blood pressure, too much cholesterol, etc. (see your doctor or cardiologist or neurologist)
  • Our "beloved poison" only allows a maximum of 10 ml (12 mg) per 24 hours, or two injections of 0.5 ml (6 mg).
  • The price, even if it has decreased somewhat, which can lead to a monthly expense of several hundred euros!

The solution : go to half-dosis (0,25 ml) :

  • This makes it possible to treat 4 attacks per 24 hours instead of 2.
  • Or reduce the daily quantity of injected product and divide the price accordingly!
  • Do not forget oxygen therapy, totally non-toxic, to promote as much as possible.

The difficulties :

  • Dose exactly 0.25 ml from a 0.5 ml syringe without graduation.
  • Doing the injection with one hand (the other used to pull the skin a little bit to make a subcutaneous) with a syringe not intended for this purpose.
  • Dare to sting manually. Psychologically it's not obvious the first time but it's actually easy and painless (yes, yes, we promise it!).

Instructions in pictures

Make a stop's push-piece:

An Imitrex SC ® vial consists of a needle (which would have believed it!), a glass tube containing the product (sumatriptan in solution) and a black rubber stopper, invisible under the label surrounding the glass tube.So I scratched the label to be able to measure the half-length occupied by the liquid contained in the syringe (quantity to be injected), as well as the distance between the back of the cap and the end of the vial.

All we have to do is add up:

  • half-length occupied by the liquid,
  • length of free space at the back of the cap

... to obtain the plunger length before the stop : ≈ 2,15 cm.

The plunger diameter must be adapted to the inner diameter of the syringe, i. e. about 6 mm. The plunger should not be too rigid in its thickness to prevent the syringe glass from breaking. So I opted for a threaded rod (diameter 3 mm) wrapped in a flexible plastic tube with an inside diameter of 4 mm.
The total lenght, ≈7 cm, is adapted to the size of my hand, so that you can push the plunger placing it in the palm of your hand.
The stop is simply made up of a nut screwed onto the rod and locked between the plastic tubes.

The manufactured plunger. It is even planned for half a dose or 1/3 of a dose:

Using the plunger:

  1. If the pain and the location you are allows you time and opportunity: wash your hands and rub the area where you are going to inject with an alcohol or isobetadine soaked cotton wool!
  2. Pull out the syringe with the injector and then unscrew it to release the syringe:
    dévisser après extraction
    demi-dose seringue
  3. Doing the injection: (I don't have a picture: I'm missing a hand  )
    • In the right hand (righhanders) take the syringe and its plunger between thumb, forefinger and middle finger at the back of the syringe. The back of the plunger is positioned in the middle of the palm of your hand.
    • Pull the skin with your left hand (top of thigh or side of abdomen, where the skin is thin) and gently prick off with the other.
    • Inject by bringing the palm closer to your fingers (not the other way around, you risk to pull the needle out of the skin).

    Position of the plunger after injection (in the example, position after 1/3 but using an empty syringe):
    poussoir en finale

  4. Replace the half-used syringe in the holder.
  5. Mark with a pencil the half-used syringe.

Injection of the other half:

It's simple: when the next attack occurs, use the injector as usual with the syringe that contains the rest of the product.

You will have noticed that in the pictures, one side of the push-button is provided for half a dose, the other for 1/3 and 2/3 (this last one for the second 1/3).
Here are the measurements for manufacturing, the threaded rod of 3 mm diameter being cut to a length of 7 cm and the plastic pipe of 4 mm:

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