BRAND NAMES
 MECHANISM OF ACTION
Terbinafine inhibits squalene epoxidase, this results in deceased synthesis of ergosterol and accumulation of toxic squalene (fungicidal effect). Ergosterol is an essential component of the fungal cell membrane. The inhibition of its synthesis results in accumulation of toxic 14α-methylated sterols and the production of a defective cell membrane with altered permeability and leakage of cellular contents.
- Treatment of onychomycosis of the toenail or fingernail due to dermatophytes (tinea unguium)
- Fingernail onychomycosis: One 250 mg tablet, once daily for 6 weeks
- Toenail onychomycosis: One 250 mg tablet, once daily for 12 weeks
 DOSAGE FORMS AND STRENGTHS
Tablet, 250 mg
- Patients with a history of allergic reaction to oral terbinafine because of the risk of anaphylaxis
 WARNINGS AND PRECAUTIONS
- Liver failure, sometimes leading to liver transplant or death, has occurred with the use of oral terbinafine. Obtain pretreatment serum transaminases. Discontinue Terbinafine (Oral) if liver injury develops.
- Taste disturbance, including taste loss, has been reported with the use of Terbinafine (Oral). Taste disturbance can be severe, may be prolonged, or may be permanent. Discontinue Terbinafine (Oral) if taste disturbance occurs.
- Smell disturbance, including loss of smell, has been reported with the use of Terbinafine (Oral). Smell disturbance may be prolonged, or may be permanent. Discontinue Terbinafine (Oral) if smell disturbance occurs.
- Depressive symptoms have been reported with terbinafine use. Prescribers should be alert to the development of depressive symptoms.
- Severe neutropenia has been reported. If the neutrophil count is <1000 cells/mm3, Terbinafine (Oral) should be discontinued.
- Stevens-Johnson syndrome, toxic epidermal necrolysis, erythema multiforme, exfoliative dermatitis, bullous dermatitis, and drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome have been reported with oral terbinafine use. If signs or symptoms of drug reaction occur, treatment with Terbinafine (Oral) should be discontinued.
Terbinafine is metabolized in liver but does not significantly inhibit or induce CYP450 (less interactions if compared to Azoles)
 PREGNANCY AND LACTATION
- Pregnancy Category B (US). It is recommended that Terbinafine (Oral) not be initiated during pregnancy.
- Nursing Mothers: After oral administration, terbinafine is present in breast milk of nursing mothers. The ratio of terbinafine in milk to plasma is 7:1. Treatment with Oral Terbinafine is not recommended in women who are nursing.
 SIDE EFFECTS
Common (>2% of patients treated with Lamisil Tablets) reported adverse events include headache, diarrhea, rash, dyspepsia, liver enzyme abnormalities, pruritus, taste disturbance, nausea, abdominal pain, and flatulence
 RELATED LINKS
|Ergosterol target : Cell membrane target||Azoles (lanosterol 14 alpha-demethylase inhibitors) : Ergosterol inhibitors||Imidazoles||Topical: Bifonazole • Clotrimazole • Econazole • Fenticonazole • Ketoconazole • Isoconazole • Miconazole • Sertaconazole • Tioconazole|
|Triazoles|| Topical: Fluconazole • Terconazole|
Systemic: Fluconazole • Itraconazole • Posaconazole • Voriconazole
|Polyene antimycotics (ergosterol binding; they form pores in the membrane)|| Topical: Nystatin |
Systemic: Amphotericin B
|Allylamines (squalene epoxidase inhibitors) : Ergosterol inhibitors|| Topical: Amorolfine • Naftifine • Terbinafine |
|Echinocandins (β-glucan synthase inhibitors) : Cell wall target||Anidulafungin • Caspofungin • Micafungin|
|Pyrimidine analogues / Thymidylate synthase inhibitors : Nucleic acid inhibitors||Flucytosine|