Need clarification

[Blackcatlover]

I have been on Actemra for three years having 4mg of Actemra per kilogram weight

administered by IV every twenty eight days. When doing 8mg of Actemra per kilogram weight I had all kinds of issues so for the last year and half it’s been 4mg. My doctor is switching me to the Actemra Actpen to be administered weekly. My prescription says 162MG/0.9ML. I can’t seem to find anyone to clarify that this number is equivalent to 4mg per kilogram weight that I was doing per month. Hope someone can help.

[SnazzyD]

So that just tells you that for every 0.9ml in that syringe you get 162mg. It depends what your weight is as to what volume you are given. So either the whole pen has been calculated as enough for 4mg per kg of your weight, or it has to be dosed. I don’t know how these pens work, whether it is all in one whole shot or you have to have the right amount from your syringe. However, whatever it is your prescribed or the dispensing pharmacist should be the one telling you and clear instructions need to be given to you.

[Blackcatlover in reply to SnazzyD]

Thanks for your reply. This switch is confusing. Just wish the prescription said 4mg per kilogram weight and I would relax. My bloodwork on 8mg per kilogram weight was horrendous. Will give it a try and see what happens.

[PMRpro Ambassador]

The injections come as a standard pre-pepared dose of 162mg whether they are every week or every second week. Bear in mind they are given more often than the infusion. And the GCA clinical trials were for the injections, not the infusions.

[Blackcatlover in reply to PMRpro]

Thanks for you reply. That’s what I’m afraid of. The standard dose for the IV treatments is 8mg and my body couldn’t handle it. I think I’ll start out every ten days and see how it goes. The Actemra is the only medicine that allowed me to get below 15mg of Prednisone. I’m now at 4mg and don’t want to regress.

[scottygirl73 in reply to Blackcatlover]

I was same as you i had problems on 8mg,so have been on 4mg infusion,but due to lockdown now on epi pen.Dosage same as you i have been fine no problems.Good luck.xx

[SnazzyD in reply to PMRpro]

So if 4mg per kg, a 162mg syringe would be for a person of 40.5kg?

[Blackcatlover in reply to SnazzyD]

I still can’t figure this out!🙃

[PMRpro Ambassador in reply to SnazzyD]

But given weekly - you can't compare apples and spuds, even if they are both pommes in French! One is sub. cut, the other is i.v.

[Blackcatlover]

Thanks for your reply. I’m so afraid to mess up this treatment. My rheumatologist wants me to inject every week but I’m afraid of what it will do to my bloodwork. I had to cut the IV dose in half. Bloodwork is fine and PMR is under control on 4mg of Prednisone. Think I’ll inject every ten days to start and check bloodwork.

[Devoid in reply to Blackcatlover]

I think this is something that you need to discuss with your consultant. The difference between the pen and I.v is not comparable, just doing your own thing could cause all sorts of problems. You will have regular bloods at first so would soon be aware if there was a problem

[SheffieldJane]

I was told that everyone receives a162 mgs dose irrespective of weight etc.

[Blackcatlover in reply to SheffieldJane]

Then why did they ask how much i weighed before filling my prescription? Very confusing.🥴

[SheffieldJane in reply to Blackcatlover]

I certainly got the impression that all patients were to be prescribed the same dose. My Rheumatology Nurse was very clear about that. Tocilizumab/Ro-Actemra patients seem to be her main responsibility at present. Training, maintenance, advice etc.

[Blackcatlover in reply to SheffieldJane]

Thanks SheffieldJane. That may well be the case but when I was given the prescribed dose of Actemra IV, my liver, white blood count, platelets and cholesterol had problems so they cut the dose in half and bloodwork was much better. It also controlled my inflammation. I was hoping to try a half dose in my Actemra pens. I don’t know if that is possible.

[SheffieldJane in reply to Blackcatlover]

I am very much in learning mode with this drug. I knew where I was with Pred but I am having to come off it now that the negative effect on my health has become apparent. I really want Tocilizumab to be the answer. Dose number 7 tomorrow. Not sure if extreme fatigue is from fast tapered Pred reaction or the R-Actemra.

[FRnina in reply to Blackcatlover]

don't think it's possible to only inject half a dose. 162 is standard and the injection goes in with a click and not a controlled plunge so you can't just stop half way. I've been on weekly doses for nearly a year and have been able to reduce to 1mg pred . No bad side effects. No fatigue. Hope to stop pred completely within a couple of months. Rheumatologists says then continue with Tocilizumab and reducing that to fortnightly injections. And then finish with that completely (I presume). I've had PMR/GCA for nearly 4 years but am hoping the end is in sight. We will see.

[PMRpro Ambassador in reply to Blackcatlover]

I can only emphasise that i.v. use of a drug and the subcutaneous use are very different. They did extensive clinical trials with the injections for GCA and the way it is used is based on that. If the dose were to be halved, then they would switch to bi-weekly injections. If you are concerned about this please discuss it with your medical team - don't try to mess about with the injected dose as it will result in inaccurate doses and you would have no idea where you are. That is why they monitor the blood levels.

[Chrisellie in reply to Blackcatlover]

Possibly to check and log any weight gain put down to the Tocilizumab /Actemra .

The 162 is standard. I had PMR GCA and LVV of the aorta. I was off pred within 7 months and off injections by 12 months. Actemra stays in your system for up to 3 months.

My weight was checked every week but had no relation to the 162.

Hope this helps

[TB1208]

A pharmacist may be able to help reassure you regarding the dosage.

[Rugger]

I am on the pre-filled pen, with 162mg of the drug. I agree with others that you should not alter the frequency to 10 days without the blessing of your medical team. I would start at weekly injections and see what your blood results are. If you need to, you may be advised to inject fortnightly, effectively halving the dose, as with your infusions. You really can't compare IV with subcutaneous injections - one goes straight into your circulation and the other is slowly released. The slow release may be better for you by not 'dumping' a large dose into your system.

Whatever is decided, I wish you all the best.

[Blackcatlover]

Sorry folks, I just posted my reply to you all on Actemra Querie by mistake. Hope you can read it there. Don’t know how to move it.

[PMRpro Ambassador in reply to Blackcatlover]

Just copy and paste it here! One more reply won't matter!