Terbinafine

Aka: Terbinafine, Lamisil, Allylamine Antifungal

1. Mechanism
   1. Allylamine Antifungal
2. Indications
   1. Topical Management (Lamisil, Terbinafine HCl 1%)
      1. Resistant dermatophyte infection (e.g. Tinea Pedis)
   2. Systemic Management (Terbinafine)
      1. Onychomycosis
3. Adverse Effects: Oral Terbinafine
   1. Uncommon effects
      1. Headache
      2. Rash
      3. Gastrointestinal upset
   2. Rare effects
      1. Cholestatic hepatitis
      2. Blood dyscrasia
      3. Stevens-Johnson Syndrome
4. Monitoring: Oral Terbinafine
   1. Protocol
      1. Baseline labs
      2. Repeat CBC after 6 weeks of continuous use if Immunodeficiency
      3. New guidelines do not require repeat LFT testing routinely
         1. Obtain repeat testing if higher risk of liver abnormality, concurrent use of Hepatotoxic Medications, or symptoms
         2. In past, LFTs have been monitored every 4 to 6 weeks
         3. Stop agent if AST or ALT >2x normal
   2. Labs
      1. Complete Blood Count and Platelet Count (if Immunodeficiency)
      2. Aspartate Aminotransferase (AST)
      3. Alanine Aminotransferase (ALT)
      4. Serum Creatinine
5. Dosing: Oral
   1. Dose
      1. Adult (and child >40 kg): 250 mg orally daily
      2. Child 20-40 kg: 125 mg (up to 187.5 mg) orally daily
      3. Child <20 kg: 67.5 mg (up to 125 mg) orally daily
   2. Duration
      1. Tinea Capitis: 6 weeks (longer course if culture grows Microsporum)
      2. Fingernail Onychomycosis: 6 weeks
      3. Toenail Onychomycosis: 12 weeks
6. Drug Interactions
   1. Cimetidine increases Terbinafine levels
   2. Rifampin decreases Terbinafine levels
   3. Increased bleeding risk with Warfarin
7. References
   1. Ely (2014) Am Fam Physician 90(10): 702-10 [PubMed]
   2. Gupta (1999) J Am Acad Dermatol 41:237-49 [PubMed]
   3. Friedlander (1999) Pediatr Infect Dis J 18(2):205-10 [PubMed]
   4. McClellan (1999) Drugs 58(1):179-202 [PubMed]
   5. Perez (1999) Mycoses 43:79-83 [PubMed]