Impact of delisting ARBs, apart from losartan, on ARB utilisation patterns in Denmark: implications for other...

Renin-angiotensin inhibitor drugs have been a target for health authority initiatives across Europe with the potential for substantial savings once generic angiotensin-converting enzyme inhibitors (ACEIs) became available without compromising care. Recently, losartan was the first angiotensin receptor blocker (ARB) to lose its patent. In Denmark, the authorities removed all other ARBs from the reimbursement list, apart from losartan, as they were all seen as essentially similar for the management of hypertension or congestive heart failure at appropriate doses, but more expensive. Similarly, all other ARB fixed-dose combinations (FDCs), apart from losartan, were removed from the reimbursement list.

The aims of the study were to (i) assess the impact of these reimbursement changes on the subsequent utilisation of losartan and other ARBs alone or as FDCs; (ii) assess changes in the prices of losartan and other ARBs post-generic losartan to calculate potential savings; and (iii) compare the impact of the policies in Denmark with other European countries to provide guidance.

This was a retrospective segmented regression analysis of an interrupted time-series design comparing utilisation patterns before and after the changes in ARB reimbursement status. Utilisation was measured in defined daily doses (DDDs). Changes in total expenditure and expenditure/DDD were also assessed over time.

Losartan utilisation grew from 31 to 33 % of total single ARB utilisation before generic losartan, to 93 % by October 2011. There was a corresponding decrease in the utilisation of all other ARBs. Both changes were significant (p < 0.001). Total expenditure on single ARBs in 2011 was 77 % below 2009 levels despite a 16 % increase in utilisation. Estimated savings were 290.5 million Danish Kroner (DKK). A similar trend was seen for losartan FDCs, which was also significant (p < 0.001).

Losartan utilisation grew appreciable following the changes. The change was much greater than seen in countries that had eased prescribing restrictions for losartan but not the other ARBs. Active therapeutic switching programmes plus education and financial incentives also significantly enhanced losartan utilisation following generics in two countries and regions; however, the increase in losartan utilisation was less than that seen in Denmark.