I've recently been put on the same tablets and folic acid due to being anemic(lack of iron/blood count).
I've just come across your post and noticed your also having the same itching problems, so am I but didn't know they was related ... I'm even getting blood drawn from scratching especially my legs !
By coincidence there was a programme on Radio 4 yesterday about PBC (Primary Biliary Cholangitis). Rare, unpleasant and frequently misdiagnosed. Main symptoms are itching, especially in the legs, and lethargy. Might be worth getting checked for it. http://www.pbcfoundation.org.uk/newly-diagnosed/what-is-pbc