Not really, there are other meds like sutent (tyrosine kinase inhibitors) that also effect thyroid function even in patients with thyroid cancer who have had their thyroid removed, it appears to increase levothyroxine requirements. So, there is more than one mechanism of action in which it alters thyroid status. The effect with sutent does not appear to be permanent and trying to keep up with thyroid status while cycling on/off the medication is the best advice at this point.
Did you gain any useful insight about sutent and treating the resulting hypothyroidism.
Thank you, for looking into this. Sutent has only been approved for a year and a half. It is for RCC but is a crossover drug, in clinical stage three trials for many other cancers. I imagine this will come up again as it becomes approved for other cancers. I look forward to any insight uou could suggect to counter act the effects of Sutent in my thyroid.
If you are cycling on/off Sutent (as most do) the TSH will fluctuate as the effect of Sutent is to block iodine uptake but this effect appears to wear off when the medication is withdrawn. That is perhaps why the TSH increase looks out of proportion to T4 decrease as TSH will move much more quickly than T4. Will look for more info on this at the meeting.
We are still learning about the abnormal thyroid function labs caused by Sutent. There may be something to it that causes the T4 to appear elevated at times despite the high TSH and hypothyroidism. The contrast may be further confounding the situation. Next week is our annual thyroid association meeting and I believe there is some research to be presented on Sutent -- will let you know.