[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Pharmacology](https://durgical.com/en/pharmacology/) › [Topical antifungals](https://durgical.com/en/pharmacology/classes/topical-antifungals/) › Efinaconazole

# Efinaconazole

## Topical antifungals?

Topical antifungals

Topical triazole solution for fungal toenail infection (onychomycosis); applied daily for about a year to the toenails only.

Updated Nov 12, 2026

## Quick facts

**Group**
[Topical antifungals](https://durgical.com/en/pharmacology/classes/topical-antifungals/)

**Target**
Lanosterol 14α-demethylase (CYP51, the fungal ERG11 enzyme)

**Used for**
Onychomycosis of the toenails

**Key effects**
Redness · Burning · Blisters

**Monitor**
Growth of clear nail over months

**ATC**
D01AC19

No doses: the clinician sets them by the current guideline.

On this page

- The basics Mechanism of action
- Indications
- Adverse effects
- Pharmacokinetics
- Memory aid

- Safety Contraindications
- Key interactions
- What is monitored
- Administration and safety
- Pregnancy and breastfeeding
- Nursing care

- Study Test yourself

- Connections Connections

## Mechanism of action

Efinaconazole is a triazole made to penetrate the nail. Like other azoles it blocks fungal lanosterol 14α-demethylase (CYP51), so ergosterol is not made and the fungal membrane fails. The nail grows out slowly, so treatment lasts many months and the clear nail appears only as new nail replaces the infected part.

- The solution penetrates the nail plate to the nail bed
- The triazole blocks fungal CYP51
- Ergosterol is not made and the membrane fails
- Healthy nail grows out over many months

## Indications

- Onychomycosis of the toenails by dermatophytes (Trichophyton rubrum, T. mentagrophytes) [Dermatophytosis (tinea) and onychomycosis →](https://durgical.com/en/conditions/dermatophytosis-and-onychomycosis/)

## Adverse effects

- Redness, itching or swelling around the nail
- Burning, stinging or pain where applied
- Blisters
- Ingrown toenail

## Contraindications

- Allergy to efinaconazole or any ingredient of the product

## Key interactions

**Nail polish and cosmetic nail products**
Not used during treatment: they block the solution from reaching the nail.

**Heat and open flames**
The solution is flammable; it is kept away from fire while applying it.

## What is monitored

- Growth of clear nail over months; reassess if no improvement
- Irritation or ingrown nails around the treated toes

## Administration and safety

- Toenails only: not on other skin, and kept out of the eyes, nose, mouth and vagina
- Applied once a day to clean, dry nails, at about the same time each day
- Flammable: no smoking or flames nearby during application
- No pedicures or nail polish during treatment

## Pregnancy and breastfeeding

Human data are lacking; pregnancy is discussed with a clinician before use.

## Nursing care

- Explain that results take months and that the course should not be stopped early
- Teach to wait after washing until the nails are completely dry before applying
- Teach foot hygiene: dry between the toes, change socks, avoid walking barefoot in shared showers
- Report severe irritation, blisters or pain

## Pharmacokinetics

**Absorption**
Applied to the toenails; designed for local action in the nail and nail bed.

## Memory aid

«EFINaconazole for the toenail's FINal layer»: a topical azole that soaks through the nail, slowly, over about a year.

## Test yourself

Think of the answer, then tap the question to see it.

## What is efinaconazole used for?

Fungal infection of the toenails (onychomycosis), mainly by dermatophytes.

## Why does efinaconazole treatment last many months?

The infected nail must grow out and be replaced by healthy nail, which is slow.

## Which safety point about the solution itself is taught to patients?

It is flammable, so it is kept away from heat and open flames during application.

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[More Pharmacology questions →](https://durgical.com/en/practice/?f=pharmacology)

## Connections

## Related drugs 4

- [Terbinafine](https://durgical.com/en/pharmacology/terbinafine/)
- [Ciclopirox](https://durgical.com/en/pharmacology/ciclopirox/)
- [Itraconazole](https://durgical.com/en/pharmacology/itraconazole/)
- [Econazole](https://durgical.com/en/pharmacology/econazole/)

## Related conditions 1

- [Dermatophytosis (tinea) and onychomycosis](https://durgical.com/en/conditions/dermatophytosis-and-onychomycosis/)

[← Back to the class: Topical antifungals](https://durgical.com/en/pharmacology/classes/topical-antifungals/)

Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.

Sources: [Efinaconazole Topical: MedlinePlus Drug Information](https://medlineplus.gov/druginfo/meds/a614050.html) (MedlinePlus (U.S. National Library of Medicine), 2026); [ATCDDD - ATC/DDD Index](https://atcddd.fhi.no/atc_ddd_index/?code=D01AC19) (WHO Collaborating Centre for Drug Statistics Methodology, 2026).

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Representative model, for educational purposes only.

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Source: https://durgical.com/en/pharmacology/efinaconazole/
License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/pharmacology/efinaconazole/