Editor—In 1995 we published a study comparing treatments with terbinafine and itraconazole for tinea infection of the toenail.1 Three years after the end of our one year study we carried out a follow up assessment in the patients who were cured. The study was double blind and assessed 26 patients from the terbinafine group and 21 patients from the itraconazole group. All patients had cured target nails, and none had applied antimycotics prophylactically on their toenails. The time to follow up was 3.1 (SD 0.2) years in the terbinafine group and 3.2 (0.2) years in the itraconazole group.
At follow up six (23%) of the patients in the terbinafine group had clinical signs of relapse on the target nail compared with five (24%) in the itraconazole group. Clinical infection of other nails could be detected only in patients treated with itraconazole (seven (33%)). Clinical signs of nail infection in at least one nail were seen in six (23%) patients in the terbinafine group and 12 (57%) in the itraconazole group (P=0.033). As patients were primarily chosen because they had cured target nails, those with mycotic changes on other nails may have entered this follow up study. At baseline the average number of affected nails was 0.6 in the terbinafine group and 0.7 in the itraconazole group; this had increased to 0.8 and 2.0 respectively (P=0.009) after three years.
Our findings agree with the results of two other recent studies. In one study only one of the 18 patients treated with terbinafine had a clinical or mycological recurrence of onychomycosis two years after effective treatment, whereas all three responders from the itraconazole group had a relapse.2 Another study investigated 47 patients with toenail mycosis who were mycologically cured two years after the end of treatment. The relapse rate was 17% (2/12) in the group treated with 250 mg terbinafine, 8% (1/13) in the group treated with 500 mg terbinafine, and 36% (7/36) in the group treated with 400 mg itraconazole.3
Although all three investigations had small numbers of patients, the differences in long term benefit are consistent and impressive. Additional studies are needed to investigate the long term outcome of antifungal treatment of onychomycosis.
References
- 1.Bräutigam M, Nolting S, Schöpf RE, Weidinger G.for the Seventh Lamisil German Onychomycosis Study Group. Randomised double blind comparison of terbinafine and itraconazole for treatment of toenail tinea infection [published correction appears in BMJ 1995; 311:1350] BMJ 1995311919–922. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2.De Cuyper C. Long term evaluation in a double blind study comparing terbinafine 250 mg daily and itraconazole 200 mg daily in 12 week treatment of toenail onychomycosis. Aust J Dermatol. 1997;38(suppl 2):1193. [Google Scholar]
- 3.Tosti A, Piraccini BM, Stinchi C, Venturo N, Colombo MD. Relapse rate of onychomycosis after systemic treatment with terbinafine or itraconazole: a 2-year follow-up. J Eur Acad Dermatol Venereol. 1996;7(suppl 2):157. [Google Scholar]