Describes classification, mechanism of action and uses of drugs.

1. ANTI-FUNGAL AGENTS
PHARMABRIDGES

2. INTRODUCTION
An antifungal drug, also known as an antimycotic drug, is a
pharmaceutical fungicide or fungistatic used to treat and prevent
mycosis such as athlete's foot, ringworm, candidiasis (thrush), serious
systemic infections such as cryptococcal meningitis, and others.

3. TYPES OF FUNGAL INFECTIONS
1. Superficial :
Affect skin – mucous membrane.
Fungi that affect keratin layer of skin, hair, nail.
Example: Tinea pedis, ring worm infection
Candidiasis : Yeast-like, oral thrush, vulvovaginitis, nail infections.
2. Deep infections
Affect internal organs such as lung ,heart , brain leading to
pneumonia , endocarditis , meningitis.

4. CLASSIFICATION OF ANTI-FUNGAL AGENTS

5. POLYENE ANTIBIOTICS
Amphotericin B and Nystatin bind to the fungal cell membrane
component ergosterol, leading to increased fungal cell membrane
permeability and the loss of intracellular constituents.
Amphotericin B and Nystatin bind to the fungal cell membrane
component ergosterol, leading to increased fungal cell membrane
permeability and the loss of intracellular constituents.
AMPHOTERICIN
 Amphotericin A & B are antifungal antibiotics.
Amphotericin A is not used clinically.
 It is a natural polyene macrolide (polyene =
many double bonds ) (macrolide = containing a
large lactone ring )
NYSTATIN
 Nystatin (originally named Fungicidin) is a polyene
antifungal medication to which many molds and
yeast infections are sensitive, including Candida.
 Due to its toxicity profile, there are currently no
injectable formulations of this drug on the US
market.
 However, nystatin may be safely given orally as well
as applied topically due to its minimal absorption
through mucocutaneous membranes such as the gut
and the skin

6. AMPHOTERICIN B NYSTATIN
ALLYLAMINES
Allylamines inhibit the enzyme squalene epoxidase, another enzyme required for
ergosterol synthesis:
• Terbinafine - marketed as Lamisil
• Amorolfine
• Naftifine
• Butenafine

7. ANTIFUNGAL AZOLES
Antifungal Azoles are synthetic drugs with broad-spectrum fungistatic
activity.
Azoles can be divided into two groups: the older imidazole agents
(clotrimazole, ketoconazole, miconazole) in which the five-member
azole nucleus contains two nitrogens and the newer triazole
compounds (fluconazole, itraconazole, and voriconazole), in which the
azole nucleus contains three nitrogens.

8. PYRIMIDINES
Flucytosine (5-flucytosine, 5-FC) is an analogue of cytosine that was
originally synthesized for possible use as an antineoplastic agent.
5-FC is converted to 5-fluorouracil inside the cell by the fungal
enzyme cytosine deaminase.
The active metabolite 5-fluorouracil interferes with fungal DNA
synthesis by inhibiting thymidylate synthetase.
Incorporation of these metabolites into fungal RNA inhibits protein
synthesis.
Flucytosine has a significant antifungal activity against Candida spp.
and the fungal organisms responsible for chromomycosis.
THIOCARBAMATES
Tolnaftate is an antifungal agent effective in the topical treatment of
dermatophyte infections and tinea.

9. NONPOLYENE ANTIBIOTICS
Griseofulvin is an oral fungistatic agent used in the long-
term treatment of dermatophyte infections caused by
Epidermophyton, Microsporum, and Trichophyton spp.
Produced by Penicillium griseofulvin, it inhibits fungal
growth by binding to the microtubules responsible for mitotic
spindle formation.
The drug binds to keratin precursor cells and newly
synthesized keratin in the stratum corneum of the skin, hair,
and nails, stopping the progression of dermatophyte infection.
In the treatment of ringworm of the beard, scalp, and other
skin surfaces, 4 to 6 weeks of therapy is often required.