ANTI FUNGAL DRUGS: MUST KNOW POINTS

* Most antifungal agents interfere with fungal cell wall synthesis and are fungistatic.

Here are few important points and dosages of important antifungal agents classwise:

1. Polyenes

NATAMYCIN

• Broad spectrum
• 5% topical suspension

AMPHOTERICIN B

• Highly effective against yeast.
• Topical 0.15%
• Subconjunctival 0.5-1 mg
• Intracameral 7.5 -10 micrograms/0.1 ml
• Intravitreal 5 micrograms/0.1 ml

Natamycin and Amphotericin B are not preferred for subconjunctival administration baecause of significant toxicity.

2. Triazoles

FLUCONAZOLE

• Most effective against Yeast.
• oral dose 400mg/day upto 4-6 weeks
• Topical 0.2%
• Subconjunctival 1-2mg. 

ITRACONAZOLE

• Supposed to have good corneal permeability and aqueous levels.
• Oral 200 mg/day.
• Topical 1%
• Subconjuntival 100mg twicw daily injection.

VORICONAZOLE

• Broad spectrum
• Topical 1%
• Subconjunctival 10 mg.
• Oral 100mg/day. 98% bioavailability with peak action in 2-3 hours.

3. Imidazoles

• This group of drugs have poor corneal penetration.
• Useful in superficial infections.

 KETOCONAZOLE

• Oral 200-400mg/day.
• topical 5% (oil based).

MICONAZOLE

• Topical 1% suspension
• Subconjunctival 5-10 mg.

CLOTRIMAZOLE

• Topical 1%.

4. Pyrimidines

FLUCYTOSINE

• Rapid resistance.
• Effective against Candida sp.
• Oral 50-150 mg/kg/day.
• Topical 2%. 

NEWER ANTIFUNGAL AGENTS

• Ravuconazole : Triazole, oral, effective against Candida and Aspergillus.
• Posaconazole: Triazole, oral, effective against Candida and Aspergillus.
• Caspofungin: Echinocandin group. Effective against Candida (fungicidal) with some activity against Aspergillus.
• Micofungin: Echinocandin group. Effective against Candida (fungicidal). Available for oral and subconjunctival administration.
• Echinocandins are the safest antifungals available with lowest hepatic and renal toxicity profiles.

INDICATIONS OF ORAL ANTIFUNGAL THERAPY:

• Large ulcer >6mm.
• Severe deep keratitis (endothelial plaque, AC penetration)
• Scleritis
• Post penetrating keratoplasty
• Endophthalmitis
• Diabetes Mellitus
• Immunocompromised

Liver function profiles should be repeated every 15 days in patients taking oral antifungals.