Is Terbinafine (Terbinafine) 250mg QD (once daily) for 90 days a suitable treatment for a 34-year-old male patient with toenail fungal infection and a partially lifted right big toenail?

Terbinafine 250mg Daily for 90 Days for Toenail Fungal Infection

Terbinafine 250mg daily for 90 days (12-16 weeks) is the first-line treatment for toenail fungal infection in this 34-year-old male patient with a partially lifted right big toenail. 1, 2

Treatment Rationale and Efficacy

• Terbinafine is considered the first-line treatment for dermatophyte onychomycosis and is generally preferred over itraconazole due to its superior efficacy both in vitro and in vivo 1
• The British Association of Dermatologists recommends terbinafine 250mg daily for 12-16 weeks (84-112 days) for toenail infections, which aligns with the proposed 90-day treatment course 2
• Terbinafine is fungicidal against dermatophytes with very low minimum inhibitory concentrations, making it highly effective for toenail fungal infections 2
• Clinical studies have demonstrated mycological cure rates of 70-80% for toenail infections with terbinafine treatment 1
• Terbinafine has shown higher cure rates compared to itraconazole in comparative trials (73% vs 45.8% at 48 weeks) 3

Considerations for the Partially Lifted Toenail

• The partially lifted right big toenail (onycholysis) is a common presentation in onychomycosis and can make treatment more challenging 1
• Re-evaluation at 6 weeks as planned is appropriate to assess if toenail extraction is needed 2
• In cases with significant onycholysis or suspected subungual dermatophytoma (dense fungal mass), partial nail removal may be necessary to improve treatment outcomes 1
• The British Association of Dermatologists guidelines note that "in cases of treatment failure, partial nail removal is indicated" particularly for the big toenail 1

Monitoring and Safety Considerations

• Baseline liver function tests are recommended before starting treatment, particularly in patients with pre-existing liver disease or history of hepatotoxic medication use 1, 4
• Common side effects include headache (most common), gastrointestinal upset, taste disturbance, and rarely skin reactions 4
• Terbinafine is contraindicated in patients with active or chronic liver disease 4
• Liver failure, though rare, has been reported with oral terbinafine use; discontinue treatment if liver injury develops 4

Prevention of Recurrence

• Advise the patient to:
  • Keep nails short and clean 1
  • Wear protective footwear in public areas like gyms, hotel rooms, and swimming pools 1
  • Use absorbent cotton socks and antifungal powders in shoes 1
  • Consider discarding old footwear or treating it with antifungal powders 1

Follow-up Recommendations

• The planned 6-week follow-up is appropriate to reassess the need for toenail extraction 2
• Complete nail regrowth may take up to 12-18 months due to the slow growth of toenails 1
• Treatment success should be evaluated based on both clinical improvement and mycological cure 1
• If there is no improvement at follow-up, consider:
  • Confirming the diagnosis with mycological testing if not already done 1
  • Evaluating for potential dermatophytoma that may require nail debridement 1
  • Assessing treatment compliance and absorption issues 1

Treatment Alternatives

• If terbinafine is contraindicated or not tolerated, itraconazole is the next best alternative (200mg daily for 12 weeks continuously, or pulse therapy at 400mg daily for 1 week per month for 3 pulses) 1
• Topical treatments alone have limited efficacy for toenail infections, particularly with significant nail involvement 1