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Letters

Treatment of toenail onychomycosis

BMJ 1999; 319 doi: https://doi.org/10.1136/bmj.319.7218.1196a (Published 30 October 1999) Cite this as: BMJ 1999;319:1196

Will paper's key message soon appear in promotional material for drug?

  1. Fred Kavalier, general practitioner (kavalier{at}londonmail.com)
  1. Kentish Town Health Centre, London NW5 2BX
  2. Mill Stream Surgery, Benson, Oxfordshire OX10 6RL
  3. Bacon Road Medical Practice, Norwich NR2 3QX
  4. University of Leeds, Leeds LS2 9JTY
  5. BMJ, London WC1H 9JR

    EDITOR—Evans and Sigurgeirsson show that one form of treatment for toenail onychomycosis (continuous terbinafine) is significantly better than another (intermittent itraconazole).1 But I find it disturbing that the journal has given such prominence (the first paper in the journal and the first item in This Week in the BMJ) to a comparative drug trial of two well established drugs that was financed entirely by the manufacturer of one of the drugs.

    The introduction to the paper cites a prevalence of onychomycosis of 2-4%, yet the study population consisted of patients with severe onychomycosis (on average a 10 year history with six toenails affected; this fact is tucked away in the last paragraph). No evidence is presented to show the relevance of the study to a wider population of patients with mild or moderate onychomycosis.

    The optimistic key message (repeated in This Week in the BMJ) that “fungal nail disease is curable” is correct only in the sense that about half of the patients who took terbinafine showed a complete cure at 72 weeks. This accords with Epstein's recent review of the success of oral treatment of onychomycosis.2 Would it not have been equally true (although more pessimistic, and certainly less promotional) to say “fungal nail disease is incurable”?

    The paper states: “As with the mycological cure rates the clinical cure rates for the continuous terbinafine groups continued to increase after treatment through to week 72. This was not the case for the intermittent itraconazole groups.” The graphs on p 1034, however, tell a different story. They show that the cure rates for both forms of treatment continued to increase substantially after treatment stopped.

    I was particularly disturbed to see that the authors acknowledged the “constant help and guidance throughout this project” of an employee of Novartis Pharmaceuticals Corporation. Why, I asked myself, was it necessary to have the constant help and guidance of the manufacturer of one of the drugs being studied?

    As a general practitioner who often receives letters from podiatrists asking me to prescribe 12-16 week courses of systemic terbinafine for relatively mild and insignificant nail discoloration, I am also concerned about the cost (£134-£178) and the cost-benefit analysis of such treatment. I predict that the paper's final key message—“Continuous terbinafine should be the current treatment of choice for onychomycosis”—will soon appear in promotional material for terbinafine. But is it a claim that should be made in the scientific pages of the BMJ, or should it be confined to the advertisements?

    Footnotes

    • a Competing interests None declared.

    References

    1. 1.
    2. 2.

    Prescribing terbinafine to every patient with the condition would be expensive

    1. Peter Rose, general practitioner (Peter.Rose{at}public-health.oxford.ac.uk),
    2. Tim Wilson, general practitioner
    1. Kentish Town Health Centre, London NW5 2BX
    2. Mill Stream Surgery, Benson, Oxfordshire OX10 6RL
    3. Bacon Road Medical Practice, Norwich NR2 3QX
    4. University of Leeds, Leeds LS2 9JTY
    5. BMJ, London WC1H 9JR

      EDITOR—The paper by Evans and Sigurgeirsson raises two issues about the treatment of toenail onychomycosis.1

      Firstly, a follow up time of 72 weeks may not be a true measure of effectiveness of treatment. Our experience in primary care is that many patients are found to have been put into remission rather than cured when followed up over longer periods.

      Secondly, terbinafine for toenail onychomycosis is usually prescribed by general practitioners. A more important issue for primary care is which patients actually require treatment. In 1996, terbinafine appeared in our PACT (prescribing analysis and cost) data among the 20 most expensive drugs, reaching number 12 at its high point. The drug was widely advertised, and patients consulted us, often on the advice of their chiropodist (chiropodists are unable to prescribe it), asking for a prescription. Most of these patients had a purely cosmetic problem.

      We consulted the local dermatology and podiatry departments and pharmaceutical adviser. The consensus was that treatment of toenail onychomycosis was necessary only if the infection was contributing to a biomechanical foot problem or if the patient also had neurological or circulatory problems. As a result we now explain to patients that they do not need treatment if the problem is purely cosmetic; most accept this. If treatment is indicated it is now started only after microbiological confirmation of infection. This policy has reduced our prescription rate to three courses of treatment over 12 months, compared with nine prescriptions over three months in 1996.

      We cannot identify any trials in the literature with follow up for longer than 72 weeks. We think that trials over three to five years should be undertaken before it is claimed that terbinafine is both an effective and a cost effective treatment. The current cost to the NHS of each patient with microbiological cure at 72 weeks is £256If our 1996 level of 18 courses of treatment per general practitioner per year were repeated across the United Kingdom the costs would be staggering.

      Footnotes

      • b Competing interests None declared.

      References

      1. 1.

      Do crinkly toenails really matter?

      1. Jessica Harris, general practitioner (baconrd{at}aol.com)
      1. Kentish Town Health Centre, London NW5 2BX
      2. Mill Stream Surgery, Benson, Oxfordshire OX10 6RL
      3. Bacon Road Medical Practice, Norwich NR2 3QX
      4. University of Leeds, Leeds LS2 9JTY
      5. BMJ, London WC1H 9JR

        EDITOR—The methodology of Evans and Sigurgeirsson's paper on the treatment of toenail infections was thorough, and the conclusions were generally sound,1 but does this warrant its being published in the BMJ? I am a general practitioner and cannot dream of using terbinafine or itraconazole for my patients, however well they work. Where were the arguments about the importance of the problem or the justification for treating it? I am surprised that the BMJ, usually so down to earth, should ignore these points.

        If 2-4% of my 5000 patients have onychomycosis it would cost £17 864 to £35 728 to treat them according to these findings. For that I could save two to five lives by implementing the Sheffield tables for lipid lowering treatment for the primary prevention of coronary heart disease,2 or do a hundred other things.

        The senior authors declare a conflict of interest, saying that they are both closely linked to the company that makes the drug they favour. How about the BMJ—do all the staff have crinkly toenails?

        Footnotes

        • c Competing interests None declared.

        References

        1. 1.
        2. 2.

        Author's reply

        1. E G V Evans, professor of medical mycology (E.G.V.Evans{at}leeds.ac.uk)
        1. Kentish Town Health Centre, London NW5 2BX
        2. Mill Stream Surgery, Benson, Oxfordshire OX10 6RL
        3. Bacon Road Medical Practice, Norwich NR2 3QX
        4. University of Leeds, Leeds LS2 9JTY
        5. BMJ, London WC1H 9JR

          EDITOR—The study is important because it shows which of two commonly prescribed antifungals agents is most effective in onychomycosis. The criticism that one of the manufacturers financed the study is naive. No single centre could feasibly be expected to recruit the numbers of patients (496) in this study within a reasonable time. The study was conducted to the highest clinical trial standards, and those who paid for it could not influence the results.

          That only half of the patients showed complete cure of the nails does not mean that fungal nail disease is incurable. The fact that the nails were not completely normal in half of cases by the strict study criteria may be misleading as in many cases the nails may not have been completely normal to start with. In the patient global assessment 79% of patients who took terbinafine were happy with their nails at the end of the study.

          How long the follow up should be in studies in onychomycosis is often debated. This study has the longest follow up of any published antifungal trial in nails. It takes about 12-18 months for toenails to be replaced, so a 72 week study is appropriate to assess efficacy. After this it is difficult to distinguish relapse from reinfection.

          Most study patients had severe onychomycosis, which reflected the profile of patients seeking treatment, so the results are likely to be valid. We could have been criticised if patients were confined to those with predominantly mild or moderate disease.

          Obviously, cost issues are important, but onychomycosis cannot be regarded as just a cosmetic problem. If left untreated the disease in individual nails will progress relentlessly and potentially will destroy the whole nail completely. Untreated nails act as a fungal reservoir, allowing infection to spread to other nails and skin and to other people. It may not be wise to delay treatment, because older patients may have peripheral vascular disease and the diminished blood supply will make treatment of their onychomycosis more difficult. Early treatment also helps prevent secondary complications—for example, cellulitis of the leg—that are likely to be more costly to treat than the onychomycosis.

          Finally, nails serve several important physical functions. Onychomycosis has been shown to affect quality of life in terms of self esteem and interfering with patients' occupations.1

          Footnotes

          • d Competing interests None declared.

          • d Professor Evans has received funds for research and attending symposia and also fees for speaking and consulting from a number of pharmaceutical companies, including Novartis Pharma and Janssen Pharmaceuticals.

          References

          1. 1.

          Roughly quarter of BMJ staff surveyed said they had crinkly toenails

          1. Marcus Müllner, acting letters editor
          1. Kentish Town Health Centre, London NW5 2BX
          2. Mill Stream Surgery, Benson, Oxfordshire OX10 6RL
          3. Bacon Road Medical Practice, Norwich NR2 3QX
          4. University of Leeds, Leeds LS2 9JTY
          5. BMJ, London WC1H 9JR

            EDITOR—We tried to answer this important question—how many BMJ staff had crinkly toenails—by using a simple questionnaire, which was distributed to 30 available members of the BMJ editorial office. The response rate was 77% (n=23) and the median age 42 (range 25-67). Two of the participants did not know what crinkly toenails were; six of the remaining 21 reported that they had crinkly toenails, of whom two had actually treated them and another two had thought about treating them.

            In conclusion, about a quarter of the BMJ staff has crinkly toenails and it seems to matter to those affected. Of course, there are several severe limitations to this small survey. The particular setting implies certain selection criteria for all participants, and generalisability is questionable. Misclassification cannot be ruled out, as the presence of crinkly toenails is self reported. In this particular situation, however, we would expect underreporting and thus the magnitude of the problem to be even bigger.

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