Hi Patricia,
Regarding your husbands experience of a 600mg imatinib dose and musculo- skeletal issues with muscular pain my history and situation might be of some interest and use.
First you do not state the reason why the specialist still prescribes the higher dose -presumably it is because of an imperfect response in the past or an event such as a loss of remission that warranted an escalation of dose.
I am surprised that none of your partners doctors have not measured his CK -creatine kinase or CPK-creatine phosphokinase because an elevated score would indicate myositis or muscle inflammation resulting as a side effect from the drug.If this measure has not been undertaken I would suggest that it be requested.
I am not surprised that other skeletal specialists hesitate to prescribe anything such as NSAIDs such as paracetemol,,diclofenic or ibuprofen to relieve the muscle pain.At a high dose of 600mg imatinib the use of long term paracetomol would hammer the liver even more,diclofenic without using safeguarding proton pump inhibitors would be likely to drill holes in the stomach.Research at Adelaide University has indicated that ibuprofen combined with imatinib is a no no as it affects the blood plasma levels of imatinib substantially.
I have been on 600mg of Glivec for 9 months now because my PCR rose to nearly 0.4 and we lost our molecular remission and there was a danger of transformation to accelerated phase/blast phase;the latest PCR is 0.009 which is a log 4.5 reduction.However my CK score hovers around 600 to 800 well above the normal reference range of 38-190 and the muscular pains are at times severe especially at night.I cant run any more and walk with a constant drag and limp as the excess enzymes in striated muscle of the right leg leads to substantial weakness;steep slopes are frightening and I need the use of a stick..
I have just had a very frank discussion with my specialist who has long experience of administering all the TKIs .It went something like we could reduce your dose to 400mg but as you have already had one loss of molecular remission if you experienced another loss of remission and we could not get it back a resultant uncontrolled transformation to accelerated/blast phase would kill you.As long as the CK score is not in the thousands and the myositis does not affect the heart or the brain then we will continue with 600mg despite substantial muscular discomfort.At a CK level below 1000 myositis is not a threat to life so one must just tough it out.
It looks like I will be on 600mg Glivec for ever as we need to ensure a durable and lasting response;the dose is quite tough and if I dont take it with a high carb meal and lots of water it leads to severe nausea,sometimes vomiting and bad headaches.
My case might or might not be exactly similar to yours but trust it helps
Best wishes
John