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Pegasys Dosing

Hi All,

So after having platelets hovering around the 1500 mark for a year the interdisciplinary team at my hospital trust has finally got nervous and recommended i go onto PEGInterferon. Im 38 and have just been having venesections and Aspirin since being diagnosed PRV JAK2+ a year ago. It was made clear to me it was entirely my choice to go onto meds and it was not a clear cut decision but the bits of research I have read that suggest PEGINterferon at an early stage can help prevent Scarring at a later one pushed me towards trying it.

Unfortunately my Haematologist openly admitted she had never used PEGInterferon and at the start of the consultation actually was not sure they even could prescribe it (had to hunt down a pharmacist to confirm). She has started me on 45mG a week raising to 90mG after 2 weeks. I had my first injection at the hospital with a nurse so i could see how it was done This was on Wednesday around midday. I was all prepared for side effects and took some paracetamol straight away and settled down for a tough night..... and nothing really happened. Woke up once in the night with a slightly achy arm and was tired next day but ultimately not much to report. Which is great if that continues but I am aware I am on the lowest dose possible right now and have only had one.

So my Question is, after all this rambling. I lead a pretty hectic life, I travel a lot for work for extended periods of time (up to 3 weeks away) and I am worried if I do get side effects they will fall on important days when i have meetings or appointments I cannot rearrange. Is there a window of opportunity to take your dose of PEG? For examply my first was midday on a Wednesday simply because I was in hospital with a nurse. Do I need to do it every week on a Wednesday around midday or can I judge it based on my calendar and move it a day or so either way? It will all me mute if I continue not to have any major side effects but it would be good to know.

Also, if it looks like this is working for me, how often are people who are already using this monitored (blood test and consultation). Like i said I am away sometimes for up to 3 weeks and could have a phone consultation if required but getting a blood test done before hand would be tricky if not impossible.

I know these are all questions for my Haematologist but, as I said, she had never used PEG before and I think I had a bit more info than she did from this forum and other sites. I will go back and ask next time I see her but some real world experiences would also be good.

Finally, and apologies for the long post. If I wanted to be referred up to Guys Hospital (where I assume they have used PEGInterferon quite a bit more) would I speak to my GP, Or my Haematologist, or write to them direct myself... I have private health care with my work that I have not utilised yet as I have been very happy with the NHS care but if that would help I may look into it.

Thanks for reading and if you made if this far thanks for pushing through to the end.


10 Replies

Hi Joe,

I’m 55 and was diagnosed with PVR and elevated platelets in October. My hematocrit was 54 at time of diagnosis and I initially had weekly venesections to bring it down to a safer level of 45. In December I was put on Pegasys 90 mg every two weeks. Like you I was lucky not to suffer any adverse side-effects other than fatigue in the following 48 hours. I’m a secondary school teacher and my haemo advised me to administer the injection on a Friday evening so that the worst of the side-effects would be over by Monday. That works pretty well for me, although I have since reduced my working hours so that I have Mondays off and still feel as I have a weekend! Because of the numerous venesections I had done in October and November, I started to become seriously anemic these last few months which left me permanently exhausted. Platelets also rose quite dramatically (apparently a normal reaction to anemia). So bottom line my haemo gave me iron intravenously which did wonders for my energy levels 😃but made the hematocrit rise again. So now I’m on 135mg every two weeks. I was a bit nervous about how I would react to the increased dosage but I injected last night and feel great today. My haemo did tell me that side-effects like fatigue and low moods do improve with time and I’ve definitely found that to be true. So good luck with your Pegasys adventure - I’m sure you’ll find a schedule that fit in with your work commitments.

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I was on a dosage of 45 for 4 weeks. Went up to 90 before I noticed a change in my PLT. No problem adjusting injection time to suit you. The maximum I have adjusted my weekly injection by is one day. First 6 months I had my bloods monitored ever 2 week. Now monthly. Travelling with injections is a pain but once you get into a routine it becomes second nature. I bought a mini medical fridge.

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Thanks both of you for your quick replies. Hopefully I’ll avoid the anemia Marrosi as my venesections have become very spread out now. Every 4 months or so. I did think about a Friday night dose but, with two small kids and me being away a lot during the week, I don’t really want to risk losing my weekend to feeling crap. Although if it proves that I don’t get many side effects I may go this route.

Good to hear you have moved you dose around a bit Eleanor. Even a day either side may really help. And if I can get my appointments down to one a month that seems it would work.

Travelling wise I was thinking of getting a cool bag or something. I’ve read PEG is ok at room temp for up to 21 days and mostly I have a fridge in the room at any hotels so I was going to try just using something like this.

For the journeys. Have you had any issues at airports with needles? Do you have a letter from your consultant?

Thanks again



Might be worthwhile asking your haematologist if you can inject every two weeks instead of weekly so you don’t have to deal with side effects every week.

My haem is happy for me to inject either a day before or a day later if I’m travelling (I guess it makes less of a difference if the injection is every two weeks).

Now that I’m on Pegasys I only see him every five to six weeks although he’s always available to talk on the phone if I have questions or need reassurance.

On a positive note Ropeginterferon should be available next year and my haem has told me that it only needs to be injected once a month.


Hi Joe. Re Guys. I’d ask your GP to refer. You’re entitled to a second opinion - and if your local haem team doesn’t have experience of the drug that seems very reasonable. However, Prof Harrison doesn’t see patients privately.


Hi Joe,

Looks like you’ve already had lots of useful advice from others and my experience is similar.

I started on 45mcg then 90mcg weekly for ET - stretched that to monthly once my counts settled down and am now on 45mcg every 3 weeks as a maintenance dose after 2 years.

Side effects are minimal and I inject at a weekend so I can rest a bit if needed but generally don’t have to.

Moving injections a day or so either way should be fine, especially if your interval is 2 or 3 weeks.

I have blood tests about every 3 months but move them to fit work trips etc.

Pegasys does need to be kept refrigerated - max at room temperature is about 24 hours I think, so cool bags and hotel fridges can help that.

I’ve never had a problem with needles on flights but always carry a letter from my haem explaining why I need to carry them.

All in all I’ve found Peg to be an easy and effective drug - hope it works well for you too.



Hi you ask all the questions we all wondered about at the beginning. You have got excellent replies already so mine will be brief.

Interferon is a slow acting drug so you may need venesections until it takes effect. 45 is a low dose but is good to start with so body gets adjusted to it. 90 may give more side effects initially.

I keep to regular frequency. Before bed. I vary site but fatty areas of stomach and bottom best for me.

Chemists do a diabetes bag that has a pouch for ice pack. That might help with your regular travel. I travelled a lot in early stages of my PV. I carried prescription with me and got a routine letter to state I needed to carry injections with me. In hand baggage only.

Have you got travel insurance? I used it to have regular blood tests while travelling and the corresponding venesecations when needed. I had another letter that said I needed them above HCT 42 which is my cut off point.

Good luck with getting into the flow, it's manageable.



Hi Joe, your situation is similar to mine. I have PV, platelets were up to 1500 and I have a very hectic stressful job and two kids. I started Pegasys soon after diagnosis as venesections are no good if one has raised platelets too. I see a really great local haemo in Hertfordshire and also the wonderful Prof Harrison. Both gave the same advice: to start Pegasys at 90mcg/ weekly. The platelets halved immediately after 4 weeks, the HCT took 3 months to reduce. After 2.5 years on it, my counts are all normal (platelets in the 300s and HCT 39 😊) and my dose reduced first to 45mcg/weekly and then to fortnightly only, which is my current dose. I inject Friday night because of work, and move it around a day or 2 if needed, due to travel or events. Initially I had bloods taken every month, then every 2 months and now every 3 - 4 months.

I have no immediate side effects at all at 45mcg. At 90mcg I had some minor side effects. This included some fatigue and diziness straight after the first ever injection, but that disappeared completely in the subsequent injections. I had some hair loss in months 4-9 which also stopped. My mouth became very dry - that persists, I need to drink a lot of water and take some saliva stimulating tablets some times. I had cotton wool spots in one eye, which naturally disappeared. And my liver counts occasionally go up, while on Peg, particularly if I take paracetamol say for a cold. So the haemos regularly check liver and thyroid levels.

When I travel and need to take the injections, I carry them in hand luggage, in a little cool bag with a small ice pack (I wrap up the Peg in a small towel so it does not freeze!), and I take the prescription and a letter from the haemo saying I need the med. No one ever checked the letter though! I kept it in hotel room fridges with no problems.

All in all, Peg is an amazing lifesaving drug. I lead a totally normal (hectic) life on it. Best of luck to you! Susana x


Hi all

Thanks everyone for the replies. It all sounds very positive and, given a bit of time, hopefully will fit into my lifestyle ok. I am determined not to give up living my normal life even if that means delaying starting on medication but reading all your stories make me think it can work.

One question for mport. Where did you go tohave blood tests when travelling, did you just rock up at a hospital and did you have to pay? Was this just in Europe? I have tried to find info on this but there is not much about but it seems if they could email / fax results that would help.

Thanks again



Hi Joe

You have already had lots of good advice but just wanted to add that I use a Frio pouch for my Peg when travelling, which works really well. I was advised to use this by a type 1 diabetic friend,who lent me one to try after a quick soak in water they stay chilled for 72 hours. I have ET and have been on 45 mcg of Peg for 6 months weekly injections and platelets in normal range now. My local hospital had no budget for Peg so they referred me to the Churchill in Oxford and the care there is excellent. Good luck!


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