sigh....substrate of the cytochrome p450 system causing inability to process drugs - incl levo ??????

[Olsbird]

so.... round and round in circles we go. For those of you not bored by my saga ( I have been hypo (not hashis) for nearly 6 years and struggling with all the drugs for the same period. Im GF. Ive tried numerous brands of levo, NDT and T3 and all of them dont agree with me - I can tick off all the side effects listed on the patient info (and more) as I increase. I cant get higher than 25 mcg levo / 1/4 tablet NDT.... my thyroid blood test results have always been out when on any of the above and noone seems to know why I struggle with anything I try to take. So Ive been to the gastroenterologist who says my guts are fine and the camera confirmed it and its nothing to do with him or oesophogitis, the endo (a professor who you would think should know what he is on about) says my problems with the meds are not his area and the side effects I complain of are caused by something else but he doesnt know what that something else may be as he is 'only an endocrinologist', my (lovely) GP says of course its the meds as you suffer these issues only when taking them, the immunologist says i havent got an allergy causing the problems so its not his area either but he is querying the above as being responsible for my sensitivities to all thyroid meds (and any other), Anyone else heard of this or think its credible. insofar as I understand it, its to do with not having the 'right' enzymes in the liver to metabolise any kinds of drugs and so you process anything differently than the norm. I dont understand if its rectifiable...

im currently on 3/4 tablet of 25mcg Eltroxin/day - so roughly 17.5 mcg. I dont know for how long I may tolerate this (its only been a week at this level, was on half a tablet for 5 weeks before increasing) as previously Ive started to get side effects at 1 full 25 mcg tablet. The side effects include; shortness of breath, burning in chest, weakness in left arm, too hot, very restless, palpitations and general feeling of awfulness. Ive put on two stone since being diagnosed and Im forever hiking hills and cycling and eating salad! I honestly dont know what else I can try or what other specialists I can see - I feel like Im just going around in ever decreasign circles.... anyone else like me??

[SlowDragon Administrator]

If you are needing to be on gluten free diet it’s likely cause of thyroid is autoimmune thyroid disease (hashimoto’s)

20% of Hashimoto’s patients never have high thyroid antibodies

Have you had ultrasound scan of thyroid

Lactose intolerance can not be seen in endoscopy (as I understand it)

Have you tried lactose free levothyroxine tablets

Lactose free liquid levothyroxine?

When were vitamin D, folate, ferritin and B12 last tested

What vitamin supplements are you currently taking, if any

We need GOOD vitamin levels to process any thyroid hormones

What about testing cortisol and DHEA levels

Have you had any adrenal testing

[Olsbird in reply to SlowDragon]

thanks SlowDragon, I definitely dont have increased antibodies and first Ive heard that you dont have to have increased antibodies to be hashis so thank you for educating me!! the ultrasound was fine. I take Vit D in the winter. my vit levels havent been tested for a while but frankly it had absolutely no effect on my ability to tolerate anythign when my levels were tested and perfect. Ive tried loads of brands and types of meds (incl liquid levo) and dont get on with any of them beyond the tiniest dose as I mentioned. I passed the synacthen test.

[Lalatoot]

We need calories to process the thyroid meds so your phrase "forever hiking hills and cycling and eating salad" rang alarm bells for me. This could be making you more hypo and adding to your weight problem.

[jimh111]

What does the substrate of p450 relate to? A substrate is the substance an enzyme, hormone etc. acts on so I find the title particularly confusing. Who mentioned p450 enzymes? Do you know which on? (they are of the form 'CYPxxx").

[Olsbird in reply to jimh111]

thanks Jim111. I was (mis)quoting the immunologist in his letter to my GP.... he verbally told me that he thought this could be the reason why I dont seem to like any drugs. What he actually wrote was 'I wondered about the possibility of atypical metobolisation of these drugs accounting for an increased pharmacologic side effect profile to a variety of medications, including levo; it being a substrate of the cytochrome P450 system'. The only thing I seem to be able to tolerate at a normal level is antibiotics, anything else I just feel stoned or woozy or weird or unwell. Im definitely not a scientist (!!) but it seemed the most plausible thing Id heard in 6 years but what I didnt understand is how further it may get me... I mean can it even be tested and/or rectified so I can tolerate drugs better....?

[SlowDragon Administrator in reply to Olsbird]

Malabsorption issues are common when hypothyroid

academic.oup.com/edrv/artic...

[jimh111 in reply to Olsbird]

I have limited knowledge of just one CYP enzymes. They are enzymes produced by the liver and help us metabolise substances. I suspect testing is very difficult as it's not a question of doing a blood test but rather finding a substance that one enzyme acts on, giving it to you and measuring the metabolites of the substance a little later. Sorry, if this is confusing, the simple answer is that it's not something a doctor could do, more research level stuff.

[Olsbird in reply to jimh111]

ok thanks anyway. maybe my GP knows a researcher desperate for someone like me to research on

[Grst]

Have you doctors considered administering the drug intravenously? I'm not sure whether that would affect the way it is metabolized in your liver but I have read several cases where people were able to tolerate the injection method over oral tablets.

Here is a link to one of the cases I found:

journals.sagepub.com/doi/pd...