Information needed about poor pain control?

pollydolly

Following years of trying different pain medications for Oesto Arthritis in my knees, I was recently informed by my doctor that I have a missing enzyme called CYP2D6.
I was taking Cocodomol 30mg/500mg with no effect, I also get very little effect from Tramadol.
Apparently having this enzyme missing means I am a very slow metaboliser of certain medications?
Has anyone heard of this and more importantly can they recommend any medication I could take to help the pain?
I am having a knee replacement in 3 weeks time and am so worried about post op pain?

barbara12

Hello pollydolly
I had an hip replaced a year ago and I must say I didn't have much pain, they usually send you back to the ward with intravenous morphine..I didn't have this ..not a clue why , but they made sure I had pain meds..so it was under control..sorry I have never heard of the CYP2D6, but I am sure this will go in your notes but I would also mention it..good luck with the op,

stickywicket

I'm sorry, pollydolly, I've never heard of this until now and I'm on this forum most days. I think only a medic can tell you what you can do. I tried looking it up and, quite frankly, I'm none the wiser :oops:

What did your GP suggest? Have you tried other methods of pain management? maybe some of this might help. http://www.arthritiscare.org.uk/PublicationsandResources/Selfmanagement

AmandaJones

Hi pollydolly,

Is this enzyme missing completely or you are little deficient in same?

Those individuals who express poor or a complete lack of enzyme function (non-metabolisers) are predisposed to the accumulation of the parent drug and will achieve excessive serum levels and prolonged half-lives of the drugs. These individuals have a tendency to become toxic on the “usual” doses of medications.

This is because all of these agents are pro-drugs that need to be metabolised to be effective and are relatively inactive as the parent drug. Codeine is converted by liver enzymes—particularly by CYP-2D6—to morphine; hence, it is the morphine, not the codeine that results in the patient’s analgesia. If the patient is “CYP-2D6 deficient,” they will not be able to convert the codeine to the active morphine component and will not receive any analgesic effect.

The same is true for hydrocodone, which is converted to its active component hydromorphone and for oxycodone, which is converted to its active component oxymorphone.

Your doc might consider trying an opioid that bypasses the CYP-2D6 metabolic pathway. Such drugs include morphine, meperidine, methadone, and fentanyl.

Hope it helps. Good luck for speedy recovery!!!
Amanda.

dreamdaisy

Hello, what a thing to find out, it must be dis-spiriting especially in view of the approaching operation. I think you need proper medical advice about this because I reckon us practising arthritics don't have the required detailed knowledge. Please discuss this with the anaesthetist because it may affect his role in the op and the surgeon who may be able to recommend post-op relief. I wish you well and I hope a solution can be found, please let us know how you get on, yes? DD

stickywicket

AmandaJones wrote:

Those individuals who express poor or a complete lack of enzyme function (non-metabolisers) are predisposed to the accumulation of the parent drug and will achieve excessive serum levels and prolonged half-lives of the drugs. These individuals have a tendency to become toxic on the “usual” doses of medications.

This is because all of these agents are pro-drugs that need to be metabolised to be effective and are relatively inactive as the parent drug. Codeine is converted by liver enzymes—particularly by CYP-2D6—to morphine; hence, it is the morphine, not the codeine that results in the patient’s analgesia. If the patient is “CYP-2D6 deficient,” they will not be able to convert the codeine to the active morphine component and will not receive any analgesic effect.

The same is true for hydrocodone, which is converted to its active component hydromorphone and for oxycodone, which is converted to its active component oxymorphone.

:? Could you translate that into English, please, Amanda

AmandaJones

Lol..SW .. this is for you..
A (pro drug that is inactive relatively) is converted to B (active drug), with help of some enzymes such as CYPD6.
In view of deficiency of these enzymes in body, this activation, can not take place. So a person doesn't get adequate analgesic effect from that drug.

Sorry for being too medical :P .

Amanda.

pollydolly

Thank you all for your help and advice. I really appreciate it!!
I am going to ask my gp to test me to see what level I am at, as some people who are deficient in CPY2D6 have none or some level of metabolising certain pain killers?
He only suggested this might be what was wrong after I had tried different strengths of Cocodomol with no effect. I remember crying in the doctors surgery post op after an operation to repair a torn meniscus in my knee!!
He prescribed me Oramorph!! I only had one dose and it gave me such a dreadful headache that I never took anymore!!!
I wish now I had asked for more information about this missing enzyme at the time!! It was only through googling it myself that I now understand about it more.
As one of you mentioned, there is very little info about it?
I think maybe some kind of 'patch' might be the answer?
Thanks again, nice to know someone is out there with advice!!!

dreamdaisy

We are a knowledgeable bunch but we are not experts by any means. The pooling of experience is a great strength on this forum because we may be able to tell people about things that they may not have come across. Good luck and please let us know how you get on. DD

tjt6768

Hi.. I too have not heard about this enzyme. Very interesting though.
I really hope something gets sorted soon. I take naproxen tablets and I'm also on fentanyl pain patches. These are 100 times the strength of morphine but without the yuckiness.. I too was on oromorph and morphine tablets before that. It was horrid. I felt like a zombie. I could barely function. The fentanyl is so much better for me. I don't even get drowsy, or very little if I do. I had to be prescribed them by the pain clinic first before my gp would.
Anyway, the very best of wishes with the op. I hope it's a great success for you.
Please keep us up to date.
X

stickywicket

Maybe it would help you to make a list of the things you'd like to ask your GP. And don't worry about asking him to clarify anything he says either. Sometimes docs can assume we have a certain amount of knowledge which we don't actually possess :roll: Check again about the oromorph as some side-effects are only temporary. On the other hand I dislike taking strong pain meds unless absolutely necessary. However, an op is a different matter. Everyone concerned should be aware that, potentially, you have a problem.

Amanda - thanks for the explanation. I kind of understand now

pollydolly

Thank you everyone, made an appointment to see my gp to discuss this, can't get an appointment till the 8th though!! My op is the 14th so hope I can get it sorted before I go in!!
Will let you all know the outcome, thanks again for all your advice, very appreciated!!

stickywicket

Good luck! I hope all goes very well.

pollydolly

Hi everyone.
Just a quick update about my visit to the gp.
Basically it wasn't a very successful visit:-(
The gp I saw had no knowledge of this Enzyme!! We did discuss me having a patch of Fentynal but she was very reluctant to prescribe them before I had my op.
She wants me to discuss my pain control with the surgical team on the day.
In some ways it makes sense but it still leaves me worried what pain medication I will be given on discharge?
I was hoping the gp would agree to doing a blood test to check to see if the enzyme is missing/ deficient ?
Sadly the gp who originally told me about this has left the surgery or I would have made an appointment with him?
Oh well, not a lot I can do now before Thursday, op in 3 days time???

stickywicket

I'm sorry you didn't get much joy from the appointment but it does seem a very rare problem and at least your GP was prepared to acknowledge her lack of knowledge I always find that more encouraging that one who tries to blind me with science.

I also think she's right that it's something that the hospital may have to deal with post-op so it's probably better to leave it to them. Hospitals usually switch pain meds anyway. I always come out with stronger stuff tan I went in with then start the process of reduction and getting back to normal. Just make sure they are aware of your problem on admission.

I do hope all goes well on Thursday. I shall be thinking of you.

pollydolly

Thank you Stickywicket. I will post on here to let you all know how it went.

stickywicket

I hope your op goes well today and there's no problems afterwards with pain relief