Nobody would prescribe 11 different drugs in the same class. But some people are on an SSRI, an antipsychotic, a mood stabiliser, an anoxyltic, etc. 11 at once is almost surely an exaggeration, but 4 at once is not unheard of (generally considered to be outside of best practice except in exceptional situations, but often not so severely outside best practice that the prescriber will be disciplined.)