N plate question

So I have been on and off nplate for about five years now the first time I got pneumonia 4 times in two months then I had a stroke due to my platelets going from like 7 to in the millions I never had a steady count it was all over the place started again about a year after that again it went ok but then I got pregnant, so I started again about 8 months ago right after my son was born it was doing pretty good at small doses and under 50,000 counts but now im at 14 with 220 mg, my doctor wanted to up my dose to 400mg today but only had 250 in the office which I allowed. Does anyone know the guidelines as far as jumping from 220 or even 250 to 400? He wants to give me another 200 on Thursday but I'm really nervous due to my past with nplate any help is appreciated

Keli:

We are finding that counts seem to peak about 7 days after the shot, so you won't know until next week what the extra 30 mg's you got today did (bad sentence structure). Anyway, you could get a bit more of a rise this week. Due to your past with very low counts, does the 14k scare you at all? How are symptoms? Do you want another 200 mg's?

I have no symptoms until I hit about 5 doesn't scare me not sure why my dr is freaking out. I don't particularly want another 200 I'm scared of n plate lol I just wasn't sure if you can jump that much or have to gradually do it. Only reason I hate being under 20 is because I don't work out and I have to be careful around my son he loves to head butt

How is he doing? I'll bet he is a lot of fun about now!

Keli, I don't think there would be anything wrong with getting another 200 mg's but you have to decide that for yourself. You could consider giving it another week to see how you do and then bump it up if necessary. You know your body better than anyone and you've been doing this for a long time.

Dosing depends on the patient's weight so it's hard to say what is a big dose or big jump and what isn't. Guidelines say to increase each week by 1mcg per kg of weight (mcg not mg) but doctors will do their own thing when they are experienced in its use.

Thank you SO much for posting that it takes 7 days for nplate to work! I've been going crazy some weeks having petichiae and giant bruises within a couple of days of having the shot. Would you say it takes 7 days, then works for about 7 days? (I get weekly shots)

Regarding jumps in dosing, I actually have 2 hemotologists, and they differ on this topic. As you know, Nplate is supposed to ONLY keep you at 50,000 or above. So with my local hematologist, who I see weekly, he goes "by the book" and if 2 consecutive weeks are below 50, he ups the dose 1 mcg per kilo (as the literature says to do...he printed out a copy for me). However, I see an expert in NYC who says that when I'm below 50, have them bump me up higher, ie. more than 1 mcg per kilo. So there are definitely differing opinions, so it seems like it's ok to do either (big or small increase). I think up to 10 mcg per kilo is allowed.

Literature says, and also in my experience that it takes 4 or 5 days for an Nplate injection to work and then a few days later for the count to be at its highest. When I was using it we aimed at count between 30 and 50. Everyone does what they most feel comfortable with.

And when would you say the nplate wears off (would that be the half life?)
Thanks,
Laura

I've never found out that information. For me, I couldn't tell as before one dose wears off the next is given. Half life does not necessarily equate to length of action.

Laura
Section 12.3 pi.amgen.com/united_states/nplate/nplate_pi_hcp_english.pdf

Nice link, Mrs.B! The following information surprised me:

12.3 Pharmacokinetics
In the long-term extension study in patients with ITP receiving weekly treatment of Nplate subcutaneously, the pharmacokinetics of romiplostim over the dose range of 3 to 15 mcg/kg indicated that peak serum concentrations of romiplostim were observed about 7 to 50 hours post dose (median: 14 hours) with half-life values ranging from 1 to 34 days (median: 3.5 days).

Half life of 1-34 days! I guess it is clear that everyone responds differently.

Peak serum, half life, neither really tells us when the drug action is at its greatest.