EFINACONAZOLE
Clinical safety rating: caution
Comprehensive clinical and safety monograph for EFINACONAZOLE (EFINACONAZOLE).
Efinaconazole inhibits fungal lanosterol 14α-demethylase, blocking ergosterol synthesis and disrupting fungal cell membrane integrity.
| Metabolism | Primarily metabolized via CYP3A4 and CYP2C19; undergoes oxidative metabolism. |
| Excretion | Approximately 1.6% of the dose is excreted unchanged in urine; the remainder is eliminated via feces (63.7%) and urine (28.5%) as metabolites, with biliary excretion playing a major role. |
| Half-life | Terminal elimination half-life is approximately 29 hours (range 22-36 hours), supporting once-daily dosing. |
| Protein binding | >99% bound to plasma proteins, primarily albumin. |
| Volume of Distribution | Volume of distribution is approximately 140 L (2.0 L/kg in a 70 kg adult), indicating extensive tissue penetration. |
| Bioavailability | Not applicable for intravenous route; as a topical agent, systemic bioavailability is negligible (<1% when applied to intact skin). |
| Onset of Action | Topical administration: clinical improvement observed within 1 week for interdigital tinea pedis and tinea cruris; 2 weeks for tinea corporis. |
| Duration of Action | After last application, therapeutic concentrations persist in stratum corneum for at least 1 week; treatment duration typically 1-2 weeks depending on indication. |
Apply a thin layer to affected area once daily for 2 weeks.
| Dosage form | SOLUTION |
| Renal impairment | No dosage adjustment required for renal impairment. |
| Liver impairment | No dosage adjustment required for hepatic impairment. |
| Pediatric use | Not approved for pediatric patients under 18 years; safety and efficacy not established. |
| Geriatric use | No specific dose adjustment; use same as adult dosing. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for EFINACONAZOLE (EFINACONAZOLE).
| Breastfeeding | No human milk data available. Based on negligible systemic absorption (plasma concentrations < 0.5 ng/mL), excretion into breast milk is unlikely. M/P ratio not determined. Caution advised but risk to infant is minimal. |
| Teratogenic Risk | Efinaconazole is classified as pregnancy category C. In animal studies, no teratogenic effects were observed at doses up to 40 mg/kg/day (approximately 200 times the human maximum clinical dose) in rats and rabbits. However, systemic absorption after topical application is negligible (approximately 0.5%), making fetal exposure minimal. Risk cannot be ruled out in first trimester but is likely low. Second and third trimester: no specific risks identified due to negligible systemic exposure. |
■ FDA Black Box Warning
None
| Serious Effects |
["Hypersensitivity to efinaconazole or any component of the formulation"]
| Precautions | ["Contains alcohol; do not use with flammable materials","Avoid contact with eyes and mucous membranes","For topical use only","Local skin reactions (e.g., ingrown toenail, dermatitis) may occur"] |
| Food/Dietary | No clinically significant food interactions. Avoid alcohol as it may exacerbate potential hepatotoxicity risk (rare). |
| Clinical Pearls |
Loading safety data…
| Fetal Monitoring | No specific monitoring required due to negligible systemic exposure. Standard prenatal care. Monitor application site for local irritation or allergic contact dermatitis. |
| Fertility Effects | No adverse effects on fertility observed in animal studies. No clinical data on human fertility. Topical application unlikely to impact fertility due to minimal systemic absorption. |
| Efinaconazole is a triazole antifungal for topical treatment of onychomycosis. Its low keratin affinity allows deep nail penetration. Apply to debrided nail plate; avoid concurrent use of occlusive dressings or nail cosmetics. Efficacy is enhanced when used with regular nail filing. Contraindicated in hypersensitivity to triazoles. |
| Patient Advice | Apply once daily to affected nails using the built-in brush. · Do not use nail polish or artificial nails during treatment. · Avoid washing or wetting the area for 1 hour after application. · Treatment duration is typically 48 weeks; continue even if nails appear improved. · Inform your doctor if you experience signs of allergic reaction (rash, itching, swelling). · Do not share the medication with others. |