Terbinafine for Onychomycosis

Onychomycosis, or fungal nail infections, are common and found all over the world. They can severely affect a person’s quality of life. They cause physical discomfort and can also affect how a person feels about their appearance. Thomas et al. (2010) studied onychomycosis in order to find out more about the condition. Many people with fungal nail infections are unwilling to seek treatment for the condition because they believe it is a mere cosmetic defect. However, if left untreated, onychomycosis can cause serious infections, and therefore treatment is required.

Terbinafine is an antifungal agent, commonly used to treat toenail onychomycosis. Research into the treatment, including a meta-analysis by Gupta et al. (2013) that assessed various different treatments for onychomycosis, have highlighted the effectiveness of terbinafine, especially given orally. The success rate of treatment with Terbinafine is reported to be high, with a large percentage of the number of people treated with the drug reporting complete or significant clearance of the fungal infection in the nail(s) treated.

The mechanism of action for terbinafine is key to its effectiveness as a treatment for onychomycosis. The drug works by targeting the squalene epoxidase enzyme. This enzyme is required for the fungal cell membrane to synthesize the ergosterol required for its structure. In humans, the corresponding molecule is cholesterol. Thus, by inhibiting squalene epoxidase, terbinafine prevents the formation of ergosterol, causing a buildup of squalene in fungal cells. This is to the detriment of the fungal cell, and it will eventually die. Importantly, terbinafine is able to stop growth of the fungi that cause onychomycosis.

Auvinen et al. (2015) completed a study to compare terbinafine with several other antifungal treatments. The results of this study found that oral terbinafine was significantly more effective than several of the other treatments including a placebo. The success of oral terbinafine was measured in terms of complete clearance of the infection. Therefore, oral terbinafine was found to be an effective treatment for onychomycosis. Fávero et al. (2022) also completed a study into the treatment of onychomycosis using both oral and topical terbinafine. The patients that were treated using oral and topical terbinafine showed good outcomes to treatment. Therefore, the results of this study also confirm that terbinafine is an effective treatment for onychomycosis.

Toenail onychomycosis is a very common fungal nail infection and is often overlooked. This infection can cause a lot of physical discomfort and also cause a lot of embarrassment to sufferers of the infection, as it can also affect how people feel about themselves in terms of their appearance. The condition can affect a person’s quality of life and therefore it is very important to treat the infection as soon as possible. As a result of its effectiveness in treating fungal nail infections, terbinafine is widely used to treat toenail onychomycosis. A number of clinical studies have provided evidence of the effectiveness of the drug. A meta-analysis by Gupta et al. (2013) of a number of treatment regimens for onychomycosis provided very positive findings for the oral antifungal terbinafine. Many of the studies that were reviewed found that oral terbinafine to be highly effective in treating fungal nail infections, with many patients experiencing complete or significant clearances of the infection. The results from the majority of the studies suggested that terbinafine, when given orally, is more effective than many topical treatments, possibly because it is able to penetrate deeper into the nail and therefore be able to clear infections that are present in deeper parts of the nail.

Studies into the safety of terbinafine, using double-blind protocols, have investigated both oral and topical applications. With respect to the topical form, the results of the studies conducted by Elewski et al. (2013) showed that there were minimal side effects, which meant that most patients could complete their treatment course without any problems, and those that did experience some adverse effects reported that they were usually mild and temporary. In contrast, the oral form of terbinafine has been reported to cause more serious side effects in some patients, and therefore it is essential to monitor patients for signs of liver damage before, during and after treatment. The individual’s medical history and any potential health risks should be taken into account before prescribing a treatment for onychomycosis.

Research also now compares and contrasts the combination of terbinafine with other antifungal treatments, showing greater success with certain combinations of oral and topical treatments, especially for eradicating infection and for prevention of relapse. In addition, as has been mentioned before, there are also two main forms of therapy: continuous treatment and pulse treatment. According to Gupta et al. ( 2020) patients may respond better to a certain type of treatment, such as continuous treatment, and other patients may respond better to a different type of treatment, for example, pulse treatment. Pulse treatment seems to be more convenient for patients as it results in better adherence to the treatment.

There is increasing evidence to support the use of terbinafine in the treatment of onychomycosis of the toenail. With many effective treatments now available to treat this often persistent and painful infection, consideration of the individual patient must be taken into account when developing treatment plans. This may include consideration of the severity of the infected nail(s), patient preference, and previous response to treatment(s). Use terbinafine with alcohol cautiously.

Citations:
Gupta, A.K., Paquet, M., Simpson, F. and Tavakkol, A., 2013. Terbinafine in the treatment of dermatophyte toenail onychomycosis: a meta‐analysis of efficacy for continuous and intermittent regimens. Journal of the European Academy of Dermatology and Venereology, 27(3), pp.267-272. https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1468-3083.2012.04584.x

Gupta, A.K., Foley, K.A., Mays, R.R., Shear, N.H. and Piguet, V., 2020. Monotherapy for toenail onychomycosis: a systematic review and network meta‐analysis. British Journal of Dermatology, 182(2), pp.287-299. https://academic.oup.com/bjd/article-abstract/182/2/287/6753169

Gupta, A.K., Polla Ravi, S., Talukder, M. and Mann, A., 2024. Effectiveness and safety of oral terbinafine for dermatophyte distal subungual onychomycosis. Expert opinion on pharmacotherapy, 25(1), pp.15-23. https://www.tandfonline.com/doi/abs/10.1080/14656566.2024.2305304

Gupta, A.K., Stec, N., Summerbell, R.C., Shear, N.H., Piguet, V., Tosti, A. and Piraccini, B.M., 2020. Onychomycosis: a review. Journal of the European Academy of Dermatology and Venereology, 34(9), pp.1972-1990. https://onlinelibrary.wiley.com/doi/abs/10.1111/jdv.16394

Thomas, J., Jacobson, G.A., Narkowicz, C.K., Peterson, G.M., Burnet, H. and Sharpe, C., 2010. Toenail onychomycosis: an important global disease burden. Journal of clinical pharmacy and therapeutics, 35(5), pp.497-519. https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1365-2710.2009.01107.x

Elewski, B.E., Ghannoum, M.A., Mayser, P., Gupta, A.K., Korting, H.C., Shouey, R.J., Baker, D.R., Rich, P.A., Ling, M., Hugot, S. and Damaj, B., 2013. Efficacy, safety and tolerability of topical terbinafine nail solution in patients with mild‐to‐moderate toenail onychomycosis: results from three randomized studies using double‐blind vehicle‐controlled and open‐label active‐controlled designs. Journal of the European Academy of Dermatology and Venereology, 27(3), pp.287-294. https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1468-3083.2011.04373.x

Auvinen, T., Tiihonen, R., Soini, M., Wangel, M., Sipponen, A. and Jokinen, J.J., 2015. Efficacy of topical resin lacquer, amorolfine and oral terbinafine for treating toenail onychomycosis: a prospective, randomized, controlled, investigator‐blinded, parallel‐group clinical trial. British Journal of Dermatology, 173(4), pp.940-948. https://academic.oup.com/bjd/article-abstract/173/4/940/6616092

Fávero, M.L., Bonetti, A.F., Domingos, E.L., Tonin, F.S. and Pontarolo, R., 2022. Oral antifungal therapies for toenail onychomycosis: a systematic review with network meta-analysis toenail mycosis: network meta-analysis. Journal of Dermatological Treatment, 33(1), pp.121-130. https://www.tandfonline.com/doi/abs/10.1080/09546634.2020.1729336

Gupta, A.K., Daigle, D. and Foley, K.A., 2014. Topical therapy for toenail onychomycosis: an evidence-based review. American Journal of Clinical Dermatology, 15(6), pp.489-502. https://link.springer.com/article/10.1007/s40257-014-0096-2

Gupta, A.K., Stec, N., Bamimore, M.A., Foley, K.A., Shear, N.H. and Piguet, V., 2020. The efficacy and safety of pulse vs. continuous therapy for dermatophyte toenail onychomycosis. Journal of the European Academy of Dermatology and Venereology, 34(3), pp.580-588. https://onlinelibrary.wiley.com/doi/abs/10.1111/jdv.16101