MS-2400

A 56-year-old man with type 2 diabetes mellitus, presents with a 6-month history of a gradually worsening fungal nail infection involving numerous toenails that have now started to become painful, particularly on walking.

After previously declining treatment, due to the extent of the infection, the associated tenderness alongside his background of type 2 diabetes, you recommend treatment.

Nail clippings confirm a Trichophyton rubrum infection. You subsequently opt to treat him with the oral anti-fungal, terbinafine.

What is the mechanism of action of this medication?