What is the optimal management of severe onychomycosis and symptomatic tinea pedis in a patient taking rosuvastatin (cholesterol medication) and ezetimibe (cholesterol medication) who is intolerant to terbinafine (antifungal medication)?

Management of Severe Onychomycosis and Symptomatic Tinea Pedis in a Patient Intolerant to Terbinafine

For a 71-year-old man with severe onychomycosis and symptomatic tinea pedis extending up the legs who is taking rosuvastatin and ezetimibe and is intolerant to terbinafine, the optimal management is oral itraconazole as first-line systemic therapy, combined with topical antifungal treatments and preventive measures. 1

Systemic Therapy Options

First-Line Therapy

• Itraconazole: Recommended as first-line treatment for dermatophyte onychomycosis in patients who cannot tolerate terbinafine 1
  • Dosing: 200 mg daily for 12 weeks continuously, or pulse therapy at 400 mg daily for 1 week per month (three pulses for toenails) 1
  • Take with food and acidic beverages for optimal absorption 1
  • Monitor hepatic function tests, especially with concomitant use of statins 1
  • Common adverse effects: headache and gastrointestinal upset 1

Important Drug Interaction Considerations

• Caution with statins: Monitor for potential interactions between itraconazole and rosuvastatin, as concurrent use may increase statin levels 1
• Monitoring: Baseline liver function tests and periodic monitoring during treatment are essential, especially with concomitant statin use 1

Alternative Systemic Option

• Fluconazole: Consider if itraconazole is not tolerated 1
  • Dosing: 150-450 mg once weekly for at least 6 months for toenail infections 1
  • May have fewer drug interactions with statins than itraconazole 1
  • Perform baseline liver function tests and monitor during therapy 1

Topical Therapy Options

• For onychomycosis: Use as adjunct to systemic therapy or for mild cases 1

  • Amorolfine 5% lacquer: Apply once or twice weekly for 6-12 months 1
  • Ciclopirox 8% lacquer: Apply once daily for up to 48 weeks 1

• For tinea pedis: 1

  • Antifungal creams/solutions: Apply miconazole, clotrimazole, or tolnaftate to affected areas
  • Treatment duration: Continue for at least 1-2 weeks after clinical resolution

Preventive Measures

• Footwear management: 1

  • Discard old contaminated footwear if possible
  • Alternatively, decontaminate shoes with naphthalene mothballs (place in tightly tied plastic bag for 3 days)
  • Apply antifungal powders inside shoes regularly
  • Consider spraying terbinafine solution into shoes periodically

• Foot hygiene: 1

  • Keep nails short and clean
  • Wear cotton, absorbent socks
  • Use antifungal powders on feet
  • Avoid sharing nail clippers

• Family treatment: Screen and treat all infected family members simultaneously to prevent reinfection 1

Monitoring and Follow-up

• Duration of follow-up: Monitor for at least 48 weeks from start of treatment to identify potential relapse 1
• Assessment: Evaluate both clinical improvement and mycological cure (negative microscopy and culture) 1
• Maintenance therapy: Consider prophylactic use of topical antifungals after cure to prevent recurrence 2

Special Considerations

• Dermatophytoma: If present (dense white lesion beneath the nail), may require mechanical removal before antifungal therapy 1
• Thick nails: Nails >2mm thick may respond poorly to treatment; consider nail debridement 1
• Recurrence prevention: Regular use of topical antifungals may help prevent recurrence of tinea pedis and subsequent onychomycosis 2

Pitfalls and Caveats

• Treatment failure: Onychomycosis has high recurrence rates (40-70%); complete eradication may require extended therapy 1
• Drug interactions: Carefully monitor for interactions between antifungals and statins; may require temporary dose adjustment of rosuvastatin 1
• Incomplete treatment: Treating only the nails without addressing tinea pedis or contaminated footwear often leads to treatment failure 1
• Persistence: Complete resolution of toenail onychomycosis may take 12-18 months due to slow nail growth, despite negative cultures 1