Cost Effectiveness of Continuous Terbinafine Compared with Intermittent Itraconazole in the Treatment of Dermatophyte Toenail Onychomycosis

Design and methods: A cost-effectiveness analysis using a model based on data from the Lamisil versus Itraconazole in Onychomycosis (L.I.ON.) study, a randomised controlled trial comparing continuous terbinafine with intermittent itraconazole. The trial included 4 treatment arms: terbinafine 250 mg/day for 12 or 16 weeks (T₁₂, T₁₆) and itraconazole 400 mg/day for 1 week in every 4 weeks for 12 or 16 weeks (I₃, I₄). Cost calculations for 6 countries (Finland, Germany, Iceland, Italy, The Netherlands, UK) included costs for medication, physician visits, laboratory tests, management of adverse events and management of relapse. Effectiveness was based on complete cure rates (mycological cure plus 100% toenail clearing). Costs per complete cure were determined and both average and incremental cost-effectiveness ratios were calculated.

Main outcome measures and results: In the L.I.ON. study, terbinafine was seen to be more effective than itraconazole (cure rates, 45.8 vs 23.4%). In most comparisons (5 of the 6 countries), the costs of T₁₂ were statistically significantly lower than those of I₃ [range: −37 to −173 euros (EUR); 1998 values; 1.172 US dollars = EUR1], indicating that T₁₂ was the dominant strategy (i.e. less expensive and more effective). One exception (Finland) showed an incremental cost-effectiveness ratio of EUR524 per additional cure. In the other 5 countries, T₁₆ and I₄ were essentially equal in cost, but the greater effectiveness of T₁₆ (cure rates, 55.1 vs 25.9%) resulted in a situation of extended dominance.