What is the comparison between fluconazole and terbinafine for tinea corporis?

Terbinafine vs. Fluconazole for Tinea Corporis

Terbinafine is superior to fluconazole for treating tinea corporis, particularly for Trichophyton species infections, due to its fungicidal activity and higher cure rates. 1

Medication Selection Based on Causative Organism

The choice between terbinafine and fluconazole should be guided by the causative dermatophyte:

• Trichophyton species infections: Terbinafine is the first-line treatment

  • Dosage: 250 mg daily for 1-2 weeks for adults 1
  • More efficacious against Trichophyton species (T. tonsurans, T. violaceum, T. soudanense) 2
  • Fungicidal mechanism of action 3

• Microsporum species infections: Fluconazole may be considered, but only in exceptional circumstances 1

  • Griseofulvin is actually more effective for Microsporum species 2
  • Itraconazole would be a better second-line option than fluconazole 2

Efficacy Comparison

Terbinafine demonstrates superior efficacy for tinea corporis:

• Achieves mycological cure in >80% of patients with tinea corporis/cruris 3
• Has fungicidal activity against dermatophytes versus fluconazole's fungistatic action 3
• Shows greater efficacy than other antifungals including griseofulvin in tinea corporis/cruris 4
• Maintains high concentrations in keratinous tissues for up to 3 months 4

A comparative study showed terbinafine had a higher mycological cure rate (87.1%) compared to griseofulvin (54.8%) at 6-week follow-up for tinea corporis/cruris 5

Treatment Duration and Administration

• Terbinafine:

  • Oral: 250 mg daily for 1-2 weeks 1
  • Topical: 1% cream applied once daily for 1 week (94% mycological cure rate) 1
  • Shorter treatment duration may improve compliance 2

• Fluconazole:

  • Only recommended in exceptional circumstances for tinea corporis 2, 1
  • Not considered first or second-line therapy for tinea corporis

Safety Profile and Considerations

• Terbinafine:

  • Generally well-tolerated with minimal drug interactions 3
  • Most common side effects: gastrointestinal (49%) and dermatological events (23%) 2
  • Rare serious adverse reactions include Stevens-Johnson syndrome and hepatic toxicity 2
  • Not recommended in patients with active or chronic liver disease 2
  • Consider baseline liver function tests in patients with history of liver disease or alcohol consumption 2

• Fluconazole:

  • Has more potential drug interactions than terbinafine 2
  • Requires dose adjustment in renal impairment 2

Treatment Monitoring and Endpoints

• Treatment should continue for at least one week after clinical resolution 1
• Clinical improvement should be expected within 1-2 weeks of starting treatment 1
• The endpoint of treatment should be mycological cure, not just clinical improvement 1
• Consider repeat mycological examination in resistant or recurrent cases 1

Special Considerations

• For extensive or resistant infections, oral therapy is preferred over topical treatment 1
• Topical treatment alone may be sufficient for limited, non-complicated tinea corporis 1
• If treatment fails, consider:
  1. Poor compliance
  2. Suboptimal absorption
  3. Relative insensitivity of the organism
  4. Reinfection 2

In conclusion, terbinafine is the preferred treatment for tinea corporis, particularly for Trichophyton species infections, with fluconazole reserved only for exceptional circumstances where other antifungals cannot be used.