Background Encouraging the prescribing of ACEIs first line vs. angiotensin receptor blockers (ARBs) has been a health authority focus with generic ACEIs as ACEIs and ARBs have similar effectiveness and there is limited coughing with ACEIs. This includes Sweden with its multiple initiatives keeping expenditure on renin-angiotensin inhibitor drugs similar between 2001 and 2007 despite appreciably increased volumes. Generic losartan became available and was reimbursed in March 2010 providing further opportunities for the authorities in Sweden to save costs with all ARBs seen as similar in managing hypertension and CHF at appropriate doses. Aims The main aim of this study was to assess changes in the utilisation of losartan vs. other single ARBs after generic losartan alongside accompanying demand-side measures. Additional aims were to (i) assess changes in the price of generic losartan and single ARB expenditure over time; (ii) suggest additional programmes, if needed; and (iii) analyse utilisation of ARB FDCs and compare with ACEI FDCs. Methods Retrospective observational study using an interrupted time series design. Results Multiple demand-side measures introduced among the 21 Counties in Sweden significantly enhanced the utilisation of generic losartan, growing from 26% to 27% of total ARBs (DDD basis) before generic losartan to 40% by August 2011. Losartan was principally generics (97% by August 2011). Expenditure/DDD for generic losartan was 10% of the pre-patent loss price in August 2011. This reduced total single ARB expenditure by 26% by the study end despite a 16% increase in utilisation. Greater utilisation of ARB FDCs than seen with ACEI FDCs. This may be due to similarities in prices between single and FDC ARBs. Discussion Multiple demand-side measures appreciably enhanced ARB prescribing efficiency, mirroring other studies. No significant increase in losartan utilisation following generics was seen in European countries where no specific measures were instigated. Losartan price reduction was in line with expectations. Conclusion Multiple and intensive demand-side measures are needed to change physician prescribing habits. Authorities cannot rely on physicians transferring their activities from one class to another without interventions.