Doctors prescribing Vancomycin for PSC in Europe

There may be legal (liability) issues that prevent US doctors having teleconference with a foreigner abroad. This could be maybe considered “practicing medicine in Turkey”.
US doctors are fine as long they are giving medical advice in the US (or existing patient traveling abroad etc).

You are lucky if you have access to Vanco.
I would simply gather some articles and research papers about Vanco success and proceed with those.