In 2004 I was diagnosed with Grave's disease (hyperthyroidism) and was prescribed some dose of propylthiouracil. Last December when I went to France on holiday (I am French!) I visited an Endocrinologist in order to make up my mind regarding an eventual operation and removal of my thyroid. As this medication is no longer prescribed there he looked it up on his computer and saw that there are few important side effects to it. He sent me for a blood test and checked the thyroid level but also the liver functions. We discovered that my liver was very damaged (I was suffering then with difficulty in digesting for over a year). I had to consult a gastroenterologist and had more blood test, scan and even MRI. That is where we discovered that my gallbladder was full of stones.
The conclusion of the consultants there was that surely enough the propylthiouracil must have damaged my liver and maybe also my gallbladder. Therefore I had to undergo the removal of the thyroid to avoid taking this medication and also the removal of my gallbladder.
So if you are taking the propylthiouracil I would advise you to ask your consultant/GP to check from time to time your liver function!!
Please refer to this website to see that what I am saying here is actually well known (not enough from the patients unfortunately):
Will be happy to answer any questions..