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Generic imatinib and associated side effects.


Hi Everybody,

I have a question about generic imatinib 400mg.

i was diagnosed with CML in early 2009, Immediatley put onto Hydroxycarbramide for 6 weeks then put on to Imatinib (Novartis) 400mg since May 4th 2009.

I have had a good response to the drug and had the usual side effects Fatigue, cramps, etc ......In 2014 entered onto the destiny trial and all went well 3 months after stopping the imatinib my PCR elevated, i was then put back on to the imatinib 400mg and within 3 months my PCR levels returned to less than 0.01 and stable. In Feb this year i was informed that i was to be moved onto generic imatinib. 400mg

However after taking the new medication for 15 days i am now experiencing excrutiating joint pain and discomfort, whilst i have severe rheumatoid arthritis which is under control with low arthritic activity at my last blood test.

My question is has anybody else who has swapped onto the generic imatinib experienced any noticable side effects with the new medication?

I have contacted my team who has suggested that i have a two week break from the medication to see if the sideeffects subside. i a now 4 days into the two weeks with symptoms subsiding slowly.

hope to hear from you soon..





I started on the generic imatinib a couple of months ago.  Since then, I have noticed a slight increase in cramps at night.  I had put it down to ageing (I'm 73) but your post made me wonder whether the new version of imatinib may be to blame.  Like you, I have been on Glivec from 2009, and decreased the dose from 400 mg to 300 and have now been on 200 for about a year.  I will raise this at my next check-up in June.

I understand that there are several different suppliers of imatinib - my pills come from Sandoz.  Does anyone else have similar questions, using the same supplier?


Hi Olivia and Stuart

I have had one month on Wockhardt and one month on Intrapharm ([email protected] apparently  deliver what they have in stock and these are the 2 generics they have). No change in side effects from either and I am awaiting my latest PCR results from blood taken May 8th.




Sandoz is a brand of generics that is owned by Novartis, who of course make the Glivec branded imatinib. Perhaps someone knows more than I do, but presumably it's the pretty much the exact same pill in a different coloured box.

Do the Sandoz imatinib look like Glivec in terms of shape, size, colour etc?


Hi Olivia

I contacted a pharmacist to query the generic drugs the response was very interesting as he pointed out that whilst the active ingrediant remains the same across the drugs the way inwhich it is bound may differ and that allergic reactions can occur to the other compounds in the drug the (Excipients) which are inactive compounds. the conclusion i got from the pharmacy is that there is a possibility that the side effects i am experiencing are asssociated.

I will let you know how I go on.



Yes, David, they do look the same, but the box is a plain one (that may be because I'm not on the standard 400 mg).  The only difference I can see is that the 100 mg pills come in strips of 10 (like Glivec) but the strips are not perforated!  I suppose old age may be to blame after all....

Hi Olivia

David is of course right - Sandoz is Novartis in disguise so my guess is it is the same as Glivec, just without the branding (hence plain box).  I haven't actually seen the Sandoz pills but from what you say, ie the fact that the pills look the same, supports this.

I'm not sure I follow the earlier point in another post regarding a pharmacist and binding mechanisms being different between the generic and Glivec - the mechanism of binding (inhibitor to target) is related to the shape of the inhibitor molecule (imatinib), which is the same whether it's Glivec or a generic.  The other TKIs will bind in different ways (and some in different places) because they are different molecules.  It's also unlikely that imatinib side effects will be affected by excipients bearing in mind the kinds of thing used as excipients are used in lots of different drugs.  I don't think it's clear what causes the side effects from imatinib but the drug itself is the obvious prime suspect since that is the active bit (and if it were the excipients I am sure we would know by now). Having said that, it is theoretically possible that individuals might have a reaction to some excipients although as I say, the kinds of things used as excipients are generally approved as being safe etc, not specifically for a given drug, so this strikes me as a bit unlikely - at least. And these reactions would be different from imatinib side effects.

What has been reported in the stopping studies (apparently) is some quite severe bone pain, both as a withdrawal symptom when stopping and as a result of going back on the drug if that becomes necessary. In some cases, this can be delayed by quite some time. It's possible therefore that this is the cause of such bone pain, rather than the use of a generic.

Obviously in each case, the best person to talk to is your specialist - they are monitoring all this and are best placed to advise/keep you up to date.

Best to all


i took the generic imatinib for about three month,i got joint pain and it was awful so i went back to gleevec.NO MORE PAIN

That is certainly interesting. From speaking to medical professionals recently at a CML conference, one thought was that the coatings on the pills were more likely to cause problems for people rather than the inactive ingredients.

Who manufactured the generic imatinib that you took?


hi David.
my generic imatinib was TEVA imatinib.I even experienced hot flashes when taking it


Hi Dear Stuart, t too have been started on this Generic Imatinib and i have taken my first one today after being on Glivec(400mg) since 2005 , i should have been taking them a couple of months sooner but had some Glivec to finish up first. Well when i opened the box i was shocked at the difference in size and colour as this Generic Imatinib is white and about half the size of the Glivec the company is listed as Intrapharm and i know it's not a good sign when Doctor's prescribe Cheap Drugs especially to those whose life depends on them...So i suspect that we are all going to be in for a difficult time with these new drugs and Our Only Hope IS Our Dear Lord Jesus Christ. Fortunately Jesus asked me do i want to Live or Die back in 2005 and i said LIVE...

Follow up as to how things progressed.

I was told to suspend taking the Imatinib which i did 12 weeks ago.

The consultant did not think the excipient would be the cause of the joint inflamation.

I went from having limited mobility to being in a wheel chair I can no longer stand or walk more than 20 feet if that. on a pain scale for the first time in my life I have hit my limit. I have been unable to sleep of get comfortable for three months now.

My last consultation with the haematologist was in June where i requested an additional blood test to ascertain if i was possibly anaemic i had a blood test on the Monday i was contacted to have an additional blood test the upshot of which showed that i had an Iron deficency and vitamin B12 and confirm a diagnosis of anaemia  I started on injections of B12 immediately and take Iron supplements. I have been taking 150mg of Diclofenac sodium every day now since the start,this reduces the joint inflamation and helps suppress the pain. I then contact my rheumatologist who gave me a Rituximab infusion. this has helped somewhat but can take up to 3 months to get to full effectiveness. My haematology team suggested that once i have had the infusion and things started to calm down that i should continue with the generic Imatinib. this i did this week after 2 tablets my joint inflamation is now back to square one i cannot straighten my legs out i am now back at pain level 10 and  struggling again. i am now totally dependent on others to manage day to day events.

in conclusion the generic Imatinib seems to have triggered a major arthritic flare up or joint inflamation side effect  that has affected every bone in my body.

i am contacting my team again this week and will let you know how things progress.


HI David thanks for posting.

The generic Imatinib 400mg  I have been on is Wockhart.

they are smaller than the Glivec tablet and have a terrible after taste with them.

I started back on them this week after a 12 week break only for my joint pain to return after 2 days.

I will be in touch with my team this week and will let you know the outcome.


Hi. I started using the Wockhart generic imatinib about 4 months ago. I think I may be lucky - not had any increase in side effects, and if anything my cramps have become less frequent.

Thanks for getting in touch Alistair.
I am glad you are managing with the new drugs.
I spoke with my team today, who are going to discuss my situation tomorrow. The current consensus is that I will be put back on Glivec for the intrim to see if my health improves.
Other than that my current situation is dire with very limited mobility.
Hope you continue to tolerate the treatment well.


After a discussion with my team I have been put back on Glivec. 4 days into the original tablets and all is well no further joint deterioration pain levels stable, had 1 cramp Mobility continues to improve slowly. All in all I am feeling optimistic. If any changes occurr I will let you know.

Good to hear, Stuart - I hope things continue well for you without another flare-up.

Hi everyone, I have been reading this with great interest, I was diagnosed with CML on 1St August 2016, I was 65, I started taking imatinib 400, I had an appointment 3 months ago and received 90 days supply, I had some tablets left so carried on using them, on opening bag with new tablets found them to be intrapharm generic, noticed the smaller size and colour, took first one and noticed the foul after taste! Have been taking them for six weeks now, and like others have noticed some side effects, I have had some crippling cramps, increasing joint pains especially hips, gone back to very puffy eyes, poor sleep and am noticing weight is increasing, have put on about 10 lbs in the six weeks, I am due to see consultant on the 11th,so will report all, Tony

Hi Tony.
How are things progressing.
Since I have gone back on imatinib things have improved significantly.
But I still have a long way to go my joint movement is improving and I can now stand and walk about 30 feet. It doesn't seem much but considering just a month ago I could not walk at all. It's a milestone.
Good luck with your treatment keep us informed.

I was on these for 3 months, the taste of the coating was awful, I was sick 30 mins after taking them, I'm now back on glivec x

To Stuart, hi and very sorry not to have replied sooner, had appointment waited 21/2 hrs, eventually a doctor came to see me and advised me that my consultant had been taken ill, asked if it was alright to see different doctor, went in explained issues I was having but she wasn't aware of my history, system was playing up so that didn't help, did the usual weighing, weight was up but didn't seem bothered, couldn't write my prescription, notes missing, nurse had gone to records to look for them and lost my next appointment booking form ! left hospital feeling deflated. Rang next day to ask for information regarding next appointment and new prescription, eventually after three weeks prescription was available to collect, lucky I'd still got some tablets, collected new tablets still generics but now on Sandoz, look identical to Gleevec, so started taking them straight away, still suffering aches in joints but sleep back to normal and cramps have gone. Waiting for next appointment on 11th December, hope all are keeping well.

I went on to Intrapharm tablets some 5 months ago without problems.  I have been on Activis for about 6 weeks and experienced some intense pains at the extremities - toes, feet occasionally hands.  These seem to have settled now, but I am about to go back on Intrapharm for six weeks to see if there is any difference.  The local hospital pharmacist tells me that they changed to Activis because Intrapharm cost £420 per box, whereas Activis cost only £30 and he would have to justify issuing Intrapharm.  I shall ask him about Sandoz pricing.