The impact of reference pricing on clinical lipid control

Reference pricing has recently been introduced into New Zealand in an attempt to curb rising pharmaceutical costs. Although budget savings may be significant, the resulting alteration of established drug prescriptions has the potential to cause harm. We undertook to assess the impact of these changes in patients switching from simvastatin to fluvastatin following the introduction of reference-based pricing in New Zealand.

The fasting lipid profiles of 262 patients in a defined geographic region were obtained after at least six weeks of fluvastatin therapy. These were compared to mean lipid levels obtained from laboratory databases for the patients while previously receiving simvastatin.

There was a significant increase in total cholesterol, LDL cholesterol and triglyceride levels (p < 0.01). The elevation was less pronounced where higher incremental doses of fluvastatin were used, although still significant for LDL cholesterol and total cholesterol (p < 0.01). Those receiving maximal therapy with fluvastatin experienced similar elevations in lipid as did those on lower doses.

The lipid elevations seen in this audit relate both to the lesser potency of fluvastatin and underdosing. In this high risk population, significant lipid elevations may conceivably produce an excess of vascular events. The responsibility to the taxpayer should be weighed carefully against the ethical responsibility to the individual patient and the potential to do harm. Subtherapeutic treatment may prove more costly than all the savings from reference pricing.