Increasing dose of 6MP

 My 17 year old son was diagnosed in Sep. 2010 with CD and was put on

 75mg of 6MP, which he has been tolerating very well. Recent labwork has

 shown that his levels are slightly below therapeutic range (not sure what

 the actual number is). The GI wants to raise the dose to 100mg. to be

 alternated every other day with 75mg. 100mg seems a bit high, my son

 weighs about 138lbs/63kg. Just would like to know if many are on such a

 high dose and how they tolerated it. We are repeating levels in 2 weeks

 to monitor his liver function and WBC's; when he first started on 6Mp back

 in October, his liver enzymes were slightly elevated, so M.D. wants to

 monitor lab values closely. Thanks!

I've been as high as 125mg and I weigh the same as your son. Good luck!

Keep in mind that Azathioprine has a different dosing scale than 6MP though. AZA is 60% weaker.

Rider-Thanks for that-I learn something new every day :)

I thought a lower dose of 6mp was equal to a larger dose of Imuran. I notice a lot of people taking 150mg and 200mg of aza but I never see people taking 150mg 6mp.

My son was on 100 mg 6-MP for about a year I think. At the time he started the drug I think he weighed about 110.

Doing the alternate day dosing sounds like a happy medium to increase his levels a little without overdoing it.

Good that the doc will be monitoring his labs closely. That's perfect.

AZA/Imuran is the prodrug for 6-MP. So when the liver processes AZA/Imuran part of the result is the metabolite 6-MP which is what has the therapeutic effect.

To end up with the same amount of 6-MP in the body you need a higher dose of AZA/Imuran than of 6-MP since part of the AZA/Imuran medication is converted to waste metabolites.

Allopurinol can be combined with AZA/Imuran only - not 6-MP. It can be used to reduce strain on the liver caused by metabolizing this medication. It blocks one of the enzyme pathways that breaks the AZA/Imuran down into 6-MP. This causes it to take more passes through the liver in order to be metabolized. The AZA/Imuran dose should be substantially reduced when it is combined with Allopurinol.

I'm normally on the Uc forum but I seen this post and thought I would reply. All of the above posters are correct about the dosing. I am only about 130lbs and I was on 100mgs of 6mp alternating with 50mgs. It depends on how well your body metabolizes it, not how much you weigh.

However, Allopurinol can indeed be used with 6mp to reduce the high levels of 6mp in the liver as well as for Imuran. This is a fairly new approach. I was on Allopurinol with my 6mp for a short while before I had an allergic reaction to it (full body rash), but my 6mp was cut drastically down to 25mgs while on it. My problem was at the higher doses of 6mp, I would go into the liver toxicity range while staying at the low end of the therapeutic level. The Allo allowed me to raise the positive affect of the 6mp and it lowered the toxicity levels. I had a Prometheus test to prove this and I was doing very well........until I had that allergic reaction that is.

Livilou, you may want to reduce even slower. 9mg to 6mg doesn't sound like a lot but many people have issues dropping the dose below 10mg. You could go down by 1mg instead of 3mg. You could also try only decreasing the dose when he's feeling 100% and not going based on time. I don't usually decrease after exactly a week, I decrease based on how I feel. If I am 100% after a week, I decrease, if not, I give myself a few more days. If you have symptoms and you decrease, they will probably get worse. That's what happened to me anyway and I had to start over. I didn't know any better at the time.