Generic Name: Tavaborole
Chemical Name: 5-Fluoro-1,3-dihydro-1-hydroxy-2,1-benzoxaborole
Molecular Formula: C7H6BFO2
CAS Number: 174671-46-6
Uses for Kerydin
Topical treatment of onychomycosis of the toenails (tinea unguium, ringworm of the nail) caused by Trichophyton rubrum or T. mentagrophytes.1
Kerydin Dosage and Administration
Apply 5% solution topically to affected toenails using dropper supplied by the manufacturer.1
Clean and dry toenails prior to application.1
Using dropper supplied by the manufacturer, place solution on each affected toenail; use dropper tip to spread solution over entire toenail surface and under toenail tip.1 More than a single drop of the solution may be necessary.1
Allow solution to dry on the toenails (this may take a couple of minutes).1
Wash hands with soap and water after applying the drug.1
Apply 5% solution to affected toenails once daily for 48 weeks.1 Use amount sufficient to cover entire toenail surface and under toenail tip.1 (See Topical Administration under Dosage and Administration.)
No special population dosage recommendations.1
Cautions for Kerydin
Manufacturer states none.1
Selection and Use of Antifungals
Safety and efficacy not established in pediatric patients.1
No overall differences in safety and efficacy in older adults relative to younger adults observed in clinical trials, but greater sensitivity of some older individuals cannot be ruled out.1
Common Adverse Effects
Interactions for Kerydin
No formal drug interaction studies to date.13
Mean peak plasma concentration was 3.54 ng/mL (range 0.618–10.2 ng/mL) after a single dose and 5.17 ng/mL (range 1.51–12.8 ng/mL) after 14 consecutive days of once-daily topical administration of the 5% solution.1
Median time to peak plasma concentration was 8.03 hours (range 0.47–24 hours) following 14 consecutive days of once-daily topical administration.5
Steady-state concentrations achieved after 14 days of once-daily topical application.1
20–25°C (may be exposed to 15–30°C).1
Actions and Spectrum
Integration of boron into the cyclic structure of a molecule allows for greater stability, greater physiologic availability at required site of action, and effective target binding capacity and selectivity.4
Exerts antifungal activity by inhibiting an aminoacyl-transfer ribonucleic acid (tRNA) synthetase (AARS), resulting in fungal protein synthesis inhibition.1 Inhibits editing domain of leucyl-tRNA synthetase;4 exhibits good relative selectivity for this fungal enzyme.4
Antifungal activity not affected by presence of keratin.5
No evidence to date that T. mentagrophytes or T. rubrum develops resistance to tavaborole following long-term topical treatment of onychomycosis caused by these dermatophytes.1
Advice to Patients
Importance of using tavaborole topical solution only for the condition prescribed.1
Advise patients that tavaborole topical solution is for external use only and to avoid contact with eyes, mouth, or vagina.1
Advise patients to avoid applying the solution to skin other than skin immediately surrounding treated toenails, and to wipe away excess solution from surrounding skin using a tissue.1
Importance of applying tavaborole topical solution with the dropper provided by the manufacturer and importance of not using the dropper for any other purpose.1
Advise patients to ensure toenails are clean and dry prior to application of the drug.1
Advise patients to wash hands with soap and water following application of the drug.1
Advise patients that tavaborole topical solution is flammable and should not be stored or used near heat or open flame.1
Importance of informing clinician if area of application shows signs of persistent irritation (e.g., redness, itching, swelling).1
Importance of informing clinician of existing or contemplated concomitant therapy, including prescription and OTC drugs and dietary or herbal supplements, as well as any concomitant illnesses.1
Importance of women informing their clinician if they are or plan to become pregnant or plan to breast-feed. 1
Importance of informing patients of other important precautionary information.1 (See Cautions.)
Excipients in commercially available drug preparations may have clinically important effects in some individuals; consult specific product labeling for details.
Please refer to the ASHP Drug Shortages Resource Center for information on shortages of one or more of these preparations.
AHFS DI Essentials. © Copyright 2017, Selected Revisions February 17, 2015. American Society of Health-System Pharmacists, Inc., 7272 Wisconsin Avenue, Bethesda, Maryland 20814.
1. Anacor Pharmaceuticals. Kerydin (tavaborole) topical solution, 5% prescribing information. Palo Alto, CA; 2014 July.
2. US Food and Drug Administration. Center for Drug Evaluation and Research. Application number204427Orig1s000: Summary review. From FDA website.
4. Del Rosso JQ, Plattner JJ. From the Test Tube to the Treatment Room: Fundamentals of boron-containing compounds and their relevance to dermatology. J Clin Aesthet Dermatol. 2014; 7:13-21. [PubMed 24578778]
5. US Food and Drug Administration. Center for Drug Evaluation and Research. Application number204427Orig1s000: Clinical pharmacology and biopharmaceutics review(s). From FDA website.
6. Del Rosso JQ. The role of topical antifungal therapy for onychomycosis and the emergence of newer agents. J Clin Aesthet Dermatol. 2014; 7:10-8. [PubMed 25053979]
7. Hay RJ. Dermatophytosis and other superficial mycoses. In: Mandell GL, Bennett, JE, Dolin R, eds. Mandell, Douglas, and Bennett's: Principles and practice of infectious diseases. Vol 2. 7th ed. Philadelphia: Elsevier; 2010: 3345-3355.
8. Hainer BL. Dermatophyte infections. Am Fam Physician. 2003; 67:101-8. [PubMed 12537173]
9. de Berker D. Clinical practice. Fungal nail disease. N Engl J Med. 2009; 360:2108-16. [PubMed 19439745]
10. Westerberg DP, Voyack MJ. Onychomycosis: Current trends in diagnosis and treatment. Am Fam Physician. 2013; 88:762-70. [PubMed 24364524]
11. Thomas J, Jacobson GA, Narkowicz CK et al. Toenail onychomycosis: an important global disease burden. J Clin Pharm Ther. 2010; 35:497-519. [PubMed 20831675]
12. Roberts DT, Taylor WD, Boyle J et al. Guidelines for treatment of onychomycosis. Br J Dermatol. 2003; 148:402-10. [PubMed 12653730]
13. US Food and Drug Administration. Center for Drug Evaluation and Research. Application number204427Orig1s000: Medical review. From FDA website.
14. US Food and Drug Administration. Center for Drug Evaluation and Research. Application number204427Orig1s000: Microbiology/Virology Review(s). From FDA website.
15. Witkowski M (PharmaDerm, East Hanover, NJ): Personal communication; 2014 Sep 23.