[green123]

#1060751

Hi everyone,

I would like to ask if it is normal for my doctor to prescribe 20mg of methimazole Monday through Friday, and 15mg on weekends? Is this shift in days a common approach with methimazole?

The reason I ask is
-For two years, I have had to alternative between 15mg and 10mg because 15mg would over supress my levels and 10 would be not enough. So for a few months, 15mg would work, but then my levels would be too low, and then I would switch to 10mg which would work for some time but then will be too low so then another switch back. (but, the dosage taken was consistent every day)

– I saw a new endo and she recommended 15mg on odd days of the month and 10mg on even days of the month.
(This caused me to still be high)

-Now, 15mg on weekdays and 20 on weekends. Still high (even higher than before)

-New recommendation: 20mg on weekdays and 15mg on weekends.

The reason I ask is I am concerned that the non-consistency in dosing is the cause of the problem because historically I was atleast “under control” or “too much control” with the consistent dosage.

With this endo, the altnerating dosage is a new thing for me. For the past 2 years, I have taken consistent dosages and things have atleast been under control. Now, it seems to be even higher than before despite high dosage.

Is this dosing approach common? Any advice? Thank you so much!

[Liz1967]

#1184503

Synthroid has a very long half life, about 7 days, so dosage can be split easily without any effect as it not totally gone until about 5 weeks. Methimazole, however, has a half life of 5-6 hours, which means it is gone from your body in about 30 hours maximum. When dosing synthroid, you can take the total weekly dose, no matter how it is split up, divide by 7 and that is pretty much your steady dose. I am not sure how steady values would be with a drug having a such a short half life. Using 28 days as your ” month”, the first dose of 14 odd days at 15 and 14 even days at 10 gives you a monthly drug total of 350 or 12.5 per day average. At 15 on weekdays (20 days) and 20 on weekends (8 days), monthly total is 460 or 16.4 per day average. At 20 on weekdays (20 days) and 15 on weekends (8 days), monthly total is 520 or 18.5 per day. As you can see, your average dose is rising. Again, methimazole has a half life slightly longer than Tylenol (4 hour half life) so I dont know how changing doses would affect things or even if an average dose really means anything, but at least if you average you can tell how much you are increasing your dose. I was on methimazole only about 6 months so I dont really have much experience with it.

[terppsi]

#1184504

Hi,

Not sure if it counts as alernating doseages, but 2.5 mg per day was too much for me, i would go hypo. So now I am taking 2,5 mg mmi Monday to Friday and nothing at weekends.
So maybe it is not that strange.

[snelsen]

#1184505

Not strange at all! I have done the same thing for years, depending on me, and how I feel, plus labs. Remember just cause pills come in certain dosages, it just might not –and frequently is not….especially with thyroid and warfarin…so doses may vary in a week. that is practicing good medicine!
Shirley

[Honeypuff]

#1184506

From my experience definitely not unusual. 10mg is never quite enough and 15mg is too much, so currently I do 15mg Mon-Fri and 10mg Sat and Sun. Since starting Estrogen replacement I have found I need to watch the labs a little more closely and don’t appear to need quite as much methimazole. So may need to adjust this dosage again in a few weeks. Definitely becoming a bit more of a juggle as I get older. I understand now why the endo said “I would have an interesting menopause”.

[Ellen_B]

#1184507

Hi all,
Has anybody switched over to the Block and Replacement regime (antithyroid drug and replacement thyroid hormone) when the adjustment of antithyroid drugs did not work? If someone has, did it work any better? Are there more problems with the Block and Replacement?

Thank you for sharing your experiences with the adjustment of the antithyroid drugs. I am interested in hearing more. It is amazing to see all the differences. It seems that every one is different to start. I guess one has to keep an open mind to the different possibilities!

[green123]

#1184508

Thank you all. Very helpful comments.

For methimazole, is the instruction usually to take all tablets in on sitting on separate (morning, afternoon, and nighttime)?

[jeff92]

#1184509

terppsi wrote:

Hi,

Not sure if it counts as alernating doseages, but 2.5 mg per day was too much for me, i would go hypo. So now I am taking 2,5 mg mmi Monday to Friday and nothing at weekends.
So maybe it is not that strange.

This is the same dose my wife is on except she takes Meth. 7 days a week at 2.5mg.. Do wanted to wait six weeks before adjusting again. Curious about which lab values promptef yor do to isuue no meth. On weekends?

[snelsen]

#1184510

Ellen, Block and Replace is mostly used in England, possible other places in Great Britain. Not sure about Europe, think not. Not used here. Of course, entirely possible, that someone, someplace in the U.S. may have used it, but it is not the Standard of Care here.

[Kimberly]

#1184511

Block & Replace is definitely not the standard of care in the U.S., although it *is* sometimes used for cases where patients (particularly children) are having difficulty getting stabilized on anti-thyroid meds.

There was a study out of Asia many years ago that indicated higher remission rates with B&R, but it was never replicated in other parts of the world – and there is concern about the potential risk of side effects that comes with using a larger dose of anti-thyroid meds.

Alternating doses is very common. I think the trick is to find a routine that will work for you to remember the days with different doses, so that might be why your doc recommended the weekend days.

Towards the end of my time on methimazole, I was taking a small dose on Mondays and Fridays only.

[Ellen_B]

#1184512

Thank you snelsen for sharing your information on the B&B. Since no one else here has mentioned being on B&B regime, it does not seem that many adults if any use it. I also remember too a thyroid specialist saying that there would be no improvement in remission rates for those who switched to Block & Replacement. It is pretty clear then that improved remission rates is not a reason for switching.

[Ellen_B]

#1184513

Thank you snelsen for sharing your information on the B&B. Since no one else here has mentioned being on B&B regime, it does not seem that many adults if any use it. I also remember too a thyroid specialist saying that there would be no improvement in remission rates for those who switched to Block & Replacement. It is pretty clear then that improved remission rates is not a reason for switching.

[Ellen_B]

#1184514

Thank you snelsen for sharing your information on the B&B. Since no one else here has mentioned being on B&B regime, it does not seem that many adults if any use it. I also remember too a thyroid specialist saying that there would be no improvement in remission rates for those who switched to Block & Replacement. It is pretty clear then that improved remission rates is not a reason for switching.

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