Antifungals

Question 1

Mycoses

Answer 1

Fungal infections

Question 2

Yeasts

Answer 2

• Single-cell fungi
• Reproduce by budding
• Can be used for baking, alcoholic bevvys, antibiotics production

Question 3

Moulds

Answer 3

Multicellular

Characterized by long, branching filaments called hyphae

Question 4

Types of Fungal Infections

Answer 4

General types
- Superficial (integumentary, mucous membranes)

• Systemic. Can be life threatening, may require prolonged therapy with drugs that frequently prove toxic. Usually in immunocompromised host
• Candida albicans in immunocompromised patients. Common yeast, due to antibiotic therapy, antineoplastics, or immunosuppressants.
• Oral candidiasis or thrush (on mucous membranes)
• Vaginal candidiasis (yeast infection)
• Dermatomycoses - skin (ringworm), nails, hair

Question 5

Polyenes

Answer 5

Amphotericin B
Nystatin

• Used for systemic infections, slow IV injection
• Bind to sterols in cell membrane lining
• Makes holes in fungi cell membranes resulting in fungal cell death

Question 6

Azoles

Answer 6

Ketoconazole

• Inhibit sterol-altering enzyme Cyp P450 enzymes
• leads to altered cell membrane which inhibits growth/kills cells
• Used for systemic and superficial fungal infections - not drug of choice

Question 7

Nystatin

Answer 7

Superficial example

• Oral infections - should be swished thoroughly in mouth as long as possible before swallowing
• Vaginal candidiasis

Question 8

Amphotericin B Adverse Effects

Answer 8

Many adverse effects

• Renal toxicity (K+ loss)
• Impairs hepatic functions
• Assess kidney and liver functions before systemic administration

To reduce severity of adverse effects, pretreat with

• antipyretic (acetaminophen)
• antihistamines (diphenhydramine)
• anti-emetics