They may be the most common drug in medicine cabinets across the country, but statins have been bumped from the top spot in the latest rankings of Australia's most costly drugs.

The cholesterol-lowering drugs used to help prevent heart attacks and stroke were the most prescribed and dispensed pharmaceutical in Australia, PBS data revealed.

Statins are the most commonly prescribed drugs in Australia. Credit:Louie Douvis

But the sheer volume of prescriptions for the relatively cheap medicine paled in comparison with the dizzying price tag of Adalimumab​; an anti-inflammatory biologic used to treat autoimmune conditions including rheumatoid arthritis and Crohn's disease.

The Australian government spent more than $311 million on just 176,062 Adalimumab (Humira) prescriptions between July 2014 and June 2015.