Yes I am aware of this. It was used in the cosmetics industry and removed there and that is what this quote is referring to:
"Bithionol: All drug products containing bithionol. Bithionol,formerly marketed as an active ingredient in various topical drug products, was shown to be a potent photosensitizer with the potential to cause serious skin disorders. Approvals of the NDA's for bithionol drug products were withdrawn on October 24, 1967 (see the Federal Register of October 31, 1967 (32 FR 15046))."
As an anti-parasite drug it was also removed too but it is still obtainable.
As an anti-parasite it is not dangerous. As a cosmetic ingredient it is.
Keep in mind triclabendazole and nitazoxanide are also unavailable in the US but are still obtainable.