Excessive range of statin dose in Western Australian primary care

Statins are very effective in reducing coronary disease and ischaemic stroke but guidelines although evolving have not been clear on statin dose.

To audit and review community statin prescribing.

A retrospective audit of the type and dose of statin dispensed was undertaken at five pharmacies in and around Perth, the capital city of Western Australia. Patients were de-identified.

Statins made up 6.5% of all prescriptions. Statin dose when adjusted for different potency effectively varied 64-fold between patients. Rosuvastatin and atorvastatin accounted for 79% of prescriptions, at a mean dose of 10 times the effective dose 50.

The extraordinarily wide variation in statin dose is at odds with the more consistent doses of other drugs used in the management of arterial disease. Unnecessarily high statin dosing increases side-effects and may not improve clinical outcomes appreciably. Rational prescribing of statins based on the pharmacodynamic evidence, with lower doses in most patients, combined with close attention to reduction of smoking, blood pressure and weight, is likely to reduce arterial disease most efficiently and safely.