Systemic Antifungal Therapy for Onychomycosis

First‑Line Oral Terbinafine

Oral terbinafine 250 mg once daily is the first‑line treatment for dermatophyte onychomycosis, administered for 6 weeks for fingernail infections and 12–16 weeks for toenail infections【1】.
Baseline liver function tests and a complete blood count should be obtained in patients with a history of hepatotoxicity, hematologic abnormalities, heavy alcohol use, or hepatitis before starting terbinafine【1】.
Common adverse effects include headache, taste disturbance (which may be permanent), gastrointestinal upset, possible aggravation of psoriasis, and a sub‑acute lupus‑like syndrome【1】.
Terbinafine is contraindicated in patients with active or chronic liver disease【2】.

Itraconazole is indicated when terbinafine is contraindicated (e.g., heart failure or concerns about hepatotoxicity)【1】.
Continuous regimen: 200 mg daily for 12 weeks【2】.
Pulse regimen: 400 mg daily for 1 week per month (two pulses for fingernail disease, three pulses for toenail disease)【2】.
The drug should be taken with food and in an acidic gastric environment to optimize absorption【1】.
Hepatic function monitoring is required for patients with pre‑existing liver abnormalities, for continuous therapy longer than 1 month, or when concomitant hepatotoxic medications are used【1】.

Fluconazole is reserved for patients who cannot tolerate terbinafine or itraconazole【1】.
Recommended dosing: 150–450 mg weekly for 3 months for fingernail disease and ≥6 months for toenail disease【1】.
Weekly dosing may improve patient adherence despite lower overall efficacy compared with daily regimens【2】.
Baseline liver function tests and complete blood count should be performed, with ongoing monitoring for high‑dose or prolonged therapy【1】.

Amorolfine 5 % lacquer – applied once or twice weekly for 6–12 months; useful for superficial and distal onychomycosis【1】.
Ciclopirox 8 % lacquer – applied daily for up to 48 weeks; indicated when systemic therapy is contraindicated【1】.

Combination of oral and topical agents is recommended when topical monotherapy alone is likely to be insufficient (moderate to severe disease)【1】.
Adding a topical agent to oral therapy can enhance overall cure rates【1】.

Wear protective footwear in public bathing facilities, gyms, and hotels to reduce re‑exposure to Trichophyton rubrum【1】.
Keep nails trimmed short and avoid sharing nail‑clipping instruments【1】.
Apply antifungal powders (e.g., miconazole, clotrimazole, tolnaftate) inside shoes and on feet; wear cotton‑absorbent socks【1】.
Discard or decontaminate old, moldy footwear by sealing shoes with mothballs in a plastic bag for at least 3 days, then airing out【1】.
Periodically spray terbinafine solution into shoes as an additional preventive measure【1】.
Treat all infected household members simultaneously because onychomycosis and tinea pedis are contagious【1】.

Artificial nails should be removed before initiating therapy to allow adequate drug penetration【2】.
Patients should be reassessed 3–6 months after therapy start; persistent infection warrants additional treatment【2】.

Griseofulvin has lower efficacy and higher relapse rates than terbinafine or itraconazole; it requires 500–1000 mg daily for 6–18 months and must be taken with fatty food【1】.
Dermatophytoma (fungal biofilm masses) can lead to treatment failure and may require more aggressive or prolonged antifungal regimens【1】.