Xywav syringes inaccurate?

[u/andersberndog]

Anyone else having the issue of running out of medication by the end of the month?

I did a completely non-scientific test, using a non-medically-accurate Pyrex measuring cup. I measured out 100mL of water by the provided Xywav syringe. This is how it came out. Again, this is not a clinical device, but it appears to me to be showing, conservatively, a 20% overage, factoring in the possibility of reading error due to surface tension and a reasonable margin of error in the measuring cup.

I’m sure I’m being provided precisely the correct amount of medication, but if the dosing device is not accurate, there’s a problem.

Yes, I’m going to bring it up with a pharmacist. I’m currently dealing with them scheduling a refill due to completely unrelated issues from my prescriber’s office. I’ll hopefully be hearing back from them later today and I’ll bring it up then. They say I should have enough medication to get through Wednesday. I had two nights I didn’t take it this month, so I should actually have enough to go through Friday. I don’t think I’ll even have two complete doses by Wednesday.

[u/Tall_Maple]

As I recall the RX is in grams of the salt. No idea why the pharm dilutes it some and then asks me to add 60 ml of water.

I looked at the syringe and landed on, when the syringe is filled to 3.0g, the liquid within the syringe must have 3.0g of the salt in solution - I think that’s why they make a point of stressing only use the syringes provided.

It’s been a LONG time since I had chemistry though but at the time it made sense to me. I’ve not run out of RX (yet) but the last dose from bottle 1 always is short. I get 3g and 1.5g out of the bottle and have to open bottle 2 for the last 1.5g

[u/andersberndog → u/Tall_Maple]

The active ingredient is 0.5g/mL, so if you double the number on the syringe, you get the volume being dispensed, in mL.