Antifungals

Terbinafine

Terbinafine is an antifungal medication that is primarily effective against dermatophytes, which are a group of fungi responsible for causing common skin, hair, and nail infections such as athlete’s foot, jock itch, and ringworm. Its mechanism of action involves inhibiting an enzyme (squalene epoxidase) essential for the synthesis of ergosterol, a key component of fungal cell membranes. This disruption leads to fungal cell death.

Terbinafine is not used for Candida albicans. While it may have some activity against certain strains of Candida, its efficacy is not as pronounced as it is against dermatophytes. Therefore, for Candida infections (such as thrush or yeast infections), other antifungal medications, particularly those from the azole class (like fluconazole or itraconazole), are usually preferred due to their more effective action against yeast fungi, including Candida.

Azoles

Azole medications are a class of antifungal drugs used to treat a variety of fungal infections. They work by inhibiting the production of ergosterol, an essential component of fungal cell membranes, thereby disrupting cell membrane formation and function.

Imidazoles:

  1. Ketoconazole: Used topically for skin infections and orally for systemic infections.
  2. Clotrimazole: Commonly used in topical creams for skin and mucous membrane infections such as vaginal yeast infections and oral thrush.
  3. Miconazole: Often used topically for skin and mucous membrane infections.
  4. Econazole: Typically used topically for skin fungal infections.

Triazoles:

  1. Fluconazole: Widely used for a variety of fungal infections, including systemic infections like cryptococcal meningitis and as a treatment and prevention for Candida infections.
  2. Itraconazole: Used for a variety of systemic fungal infections.
  3. Voriconazole: Often used to treat serious, invasive fungal infections such as aspergillosis and candidemia.

Preferred Antifungals

Tinea

  • Topical
    • 1st line: Terbinafine topical OD-BD for 7/14 days
    • 2nd line: Clotrimazole, Micononazole, Econazole, Ketoconazole
  • Oral
    • 1st line: Terbinafine 250mg oral OD for 14/7
    • 2nd line: Fluconazole 150mg oral weekly for 6/52
    • 3rd line: Itraconazole (Sporanox) 100mg oral daily for 2-4 weeks
    • 4th line: Griseofulvin 500mg oral daily for 6-8 weeks (Microsporum)

Onchymycosis

  • 1st line: Terbinafine 250 mg oral OD until clinical clearance   
  • 2nd line: fluconazole 150 to 300 mg orally, once weekly until clinical clearance   
  • 3rd line: itraconazole (Sporanox capsule) 200 mg orally, BD for 1 week every month until clinical clearance

Candidiasis

  • Oral
    • Miconazole gel oral QID for 1-2 weeks
    • Nystatin oral QID for 1-2 weeks
    • Amphotericin B lozenges oral QID for 1-2 weeks (over 2 year old) 
  • Angular Chelitis
    • Clotrimazole cream BD for 14/7
    • Miconazole cream BD for 14/7
  • Vaginal
    • Clotrimazole pessary PV stat at night
    • Fluconazole 150mg oral stat
    • Repeat for up to 4 days if not responding
  • Skin
    • Clotrimazole topical BD
    • Micononazole topical BD
    • Econazole topical BD
    • Ketoconazole topical OD