Evaluating the costs and benefits of using combination therapies

To the Editor: Clarke and Avery make an important point highlighting the substantial costs arising from a loophole allowing multibrand fixed-dose combinations (FDCs) listed on the Pharmaceutical Benefits Scheme (PBS) to retain price premiums long after premiums on their individual components have eroded.1

However, we should not throw the baby out with the bathwater. FDCs could reduce costs for the PBS if used instead of more expensive therapies (eg, the Kanyini-GAP polypill trial2) and reduce patient costs with fewer copayments. Also, FDCs have most benefit when non-adherent patients are “switched up” from partial treatment on single pills to fuller treatment with FDC-based regimens.2,3 These benefits were not the focus of Clarke and Avery's article. Their focus on the costs of combinations versus the separate components is understandable; current regulatory and reimbursement paradigms focus on “straight substitution” (ie, switching people stabilised on specific medications to an FDC containing the same drugs at equivalent doses). However, FDCs are best considered as treatment options to overcome treatment inertia and poor adherence. Defining the eligible population as those already taking recommended drugs at specific doses effectively defines a group with the least to benefit from combination therapy.

Currently, the PBS spends around $3 billion annually on lipid-lowering, blood pressure-lowering, antidiabetic and antiplatelet therapies — yet most Australians at high risk of cardiovascular disease do not receive all recommended medications over the long term.4 Appropriate use of combination therapy in chronic disease management potentially contributes to a more sustainable and equitable health system. However, the role of FDCs in closing treatment gaps in a cost-effective way has far to travel from our current situation.