BTW, is there a law in UK (or US) about using generic products? Over here, a doctor prescribes something, but pharmacies have the responsibility to offer cheape

BTW, is there a law in UK (or US) about using generic products? Over here, a doctor prescribes something, but pharmacies have the responsibility to offer cheapest product, typically a generic replacement when available, unless the doctor justifies a specific brand with specific medical reasons (which are rather hard to come by).