Antifungal Drugs

ANTIFUNGAL DRUGS

These are drugs used for superficial and deep (systemic) fungal infections.

A disquietening trend after 1950s is the rising prevalence of more sinister type of fungal infections which are, to a large extent, iatrogenic. These are associated with the use of broad-spectrum antibiotics, corticosteroids, anticancer/immunosuppressant drugs, dentures, indwelling catheters and implants, and emergence of AIDS. As a result of breakdown of host defence mechanisms, saprophytic fungi easily invade living tissue.

Many topical antifungals have been available since the antiseptic era. Two important antibiotics: amphotericin B—to deal with systemic mycosis, and griseofulvin—to supplement attack on dermatophytes were introduced around 1960. Antifungal property of flucytosine was noted in 1970, but it could serve only as a companion drug to amphotericin. The development of imidazoles in the mid 1970s and triazoles in 1980s has been an advancement. Some new compounds like terbinafine have been added lately.

Classification

1. Antibiotics

Polyenes: Amphotericin B (AMB), Nystatin, Hamycin, Natamycin (Pimaricin)

Heterocyclic Benzofuran: Griseofulvin

2. Antimetabolite  Flucytosine (5FC)

3. Azoles

Imidazoles (topical): Clotrimazole, Econazole, Miconazole, Oxiconazole

(systemic): Ketoconazole

Triazoles (systemic): Fluconazole, Itraconazole, Voriconazole

4. Allylamine   Terbinafine

5. Other Topical Agents

Tolnaftate, Undecylenic acid, Benzoic acid, Quiniodochlor, Ciclopirox olamine, Butenafine, Sod. thiosulfate.