KERYDIN
Clinical safety rating: caution
Comprehensive clinical and safety monograph for KERYDIN (KERYDIN).
KERYDIN (tavaborole) is a boron-based antifungal that inhibits fungal protein synthesis by blocking the activity of leucyl-tRNA synthetase, thereby preventing aminoacylation of tRNA(Leu) and impairing protein synthesis in dermatophytes.
| Metabolism | Tavaborole is metabolized primarily via glucuronidation (UGT1A9, UGT1A1, UGT2B15) and oxidation (CYP3A4, CYP2C19, CYP2C9, CYP1A2, CYP2B6, CYP2D6). The main metabolites are tavaborole glucuronide and tavaborole N-oxide. |
| Excretion | Primarily hepatic metabolism; renal excretion of metabolites accounts for approximately 88% of the dose, with negligible fecal excretion (<1% as unchanged drug). |
| Half-life | Terminal elimination half-life is approximately 24 hours, supporting once-daily topical application. |
| Protein binding | Approximately 94% bound to plasma proteins, primarily albumin. |
| Volume of Distribution | Volume of distribution is not well characterized due to minimal systemic absorption; estimated to be less than 5 L/kg, indicating limited tissue distribution. |
| Bioavailability | Systemic bioavailability is low (<5% of applied dose) following topical administration to toenails, with negligible absorption. |
| Onset of Action | Onset of action is variable and not well-defined; visible clinical improvement typically observed within 2 to 4 weeks of daily topical application. |
| Duration of Action | Duration of action persists with continued once-daily application; clinical cure is typically achieved after 6 weeks of treatment, with resolution of onychomycosis. |
| Molecular Weight | 468.6 |
8 mg/kg (max 800 mg) IV over 2 hours once daily for 14 days
| Dosage form | SOLUTION |
| Renal impairment | No adjustment needed |
| Liver impairment | No adjustment needed |
| Pediatric use | 8 mg/kg (max 800 mg) IV over 2 hours once daily for 14 days; safety in children <2 years not established |
| Geriatric use | No specific adjustment; use with caution due to potential renal impairment |
| 1st trimester | Contraindicated due to risk of fetal harm based on animal studies and potential for teratogenicity. Use only if benefit clearly outweighs risk. |
| 2nd trimester | Contraindicated unless no safer alternative; limited human data but animal studies show adverse effects. |
| 3rd trimester | Contraindicated due to potential for neonatal toxicity; avoid during third trimester unless essential. |
Clinical note
Comprehensive clinical and safety monograph for KERYDIN (KERYDIN).
| Placental transfer | Believed to cross the placenta based on molecular weight and animal studies; extent not quantified in humans. |
| Breastfeeding | Excretion into human milk unknown; however, due to potential for serious adverse reactions in nursing infants, breastfeeding is not recommended during therapy and for 6 months after last dose. |
■ FDA Black Box Warning
None.
| Serious Effects |
Hypersensitivity to tavaborole or any excipientPregnancy (absolute contraindication due to teratogenicity in animal studies)
| Precautions | Not for ophthalmic, oral, or intravaginal use. Avoid contact with eyes and mucous membranes. If irritation or allergic reaction occurs, discontinue use. The safety and efficacy in immunocompromised patients have not been established. |
| Food/Dietary | No known food interactions with topical KERYDIN. Avoid consuming the medication orally. |
| Clinical Pearls |
Loading safety data…
| Lactation Rating | Avoid |
| Teratogenic Risk | KERYDIN (tavaborole) is classified as Pregnancy Category C. There are no adequate and well-controlled studies in pregnant women. In animal studies, tavaborole was not teratogenic in rats or rabbits at doses up to 75 and 300 mg/kg/day (approximately 20 and 75 times the maximum recommended human dose based on AUC comparisons). However, embryofetal toxicity (reduced fetal body weight and delayed ossification) was observed in rats at maternally toxic doses. Use during pregnancy only if potential benefit justifies potential risk to the fetus. |
| Fetal Monitoring | No specific maternal or fetal monitoring is required beyond routine prenatal care. However, if used during pregnancy, monitor for any signs of maternal toxicity or adverse effects. |
| Fertility Effects | In animal studies, tavaborole had no effects on fertility or reproductive performance in male or female rats at oral doses up to 75 mg/kg/day (approximately 20 times the maximum recommended human dose based on AUC). No human data on fertility effects are available. |
| KERYDIN (tavaborole) is a topical antifungal for onychomycosis. It is an oxaborole that inhibits fungal protein synthesis. Apply to affected toenails once daily for 48 weeks. Cure rates are modest; complete cure about 6.5% vs 0.5% vehicle. No systemic absorption concerns. Avoid use in patients with known hypersensitivity to boron-containing compounds. Can be used with nail polish, but remove before application. Not for ophthalmic or oral use. |
| Patient Advice | Apply KERYDIN to the affected toenail(s) once daily as directed. · Use the dropper to apply enough solution to cover the entire nail and surrounding skin. · Allow the solution to dry completely before wearing socks or shoes. · Continue treatment for the full 48 weeks even if the nail looks better. · Do not use on fingernails, in the eyes, or by mouth. · Keep the bottle tightly closed and store at room temperature. · Inform your doctor if you have any allergic reactions or signs of skin irritation. |