Secretagentman has sent through another casting notice, this time for Episode 5.03.
#503 will feature two British women in their 30's,Abigail (Theresa's nurse)& Theresa (who suffers from dementia). Also a British working class man in his late 40's and a Filipino 'doctor'. Naturally all names and professions could, and likely will, change.
Source: Secretagentman