Antifungals

Question 1

which individuals are susceptible to fungal infections

Answer 1

1. Long term broad-spectrum antibiotics
2. Chemotherapeutic patients
3. HIV and immunocompromised
4. Diabetes, elderly, pregnant, burn wound victims

Question 2

What are some local and systemic fungal infections

Answer 2

Local:
Canidiasis
Tinea vesicolor
Dermatophytoses

Systemic:
Pulmonary aspergillis
Canidiasis
Histoplasmosis
Cryptococcal meningitis

Question 3

Classify antifungal agents

Answer 3

Azoles
Polyenes
Antifungal that inhibits the nucleic acid synthesis
Antifungals that inhibit the glucan biosynthesis pathway
Antifungi that bind to nonsterol lipids altering cell membrane integrity

Question 4

Discuss Azoles
- Examples
- MOA
- Clinical use of itraconazole

Answer 4

Ketoconozole, fluconazole, itraconazole

Inhibit the synthesis of ergosterol which is an essential component of the fungal cell membrane, disrupts membrane integrity and function

Tx. of flucanazole resistant canida and molds

Question 5

Discuss polyenes
- Examples
- MOA
- Clinical uses of Nystatin

Answer 5

• Amphotericin and Nystatin (only available topically and orally)
• Binds to ergosterol in the fungal cell wall, generates a pore, loss of small molecules and electrolytes (potassium) leading to cell death

Oral thrush, denture stomatitis, antibiotic-associated stomatitis etc.

Question 6

Discuss antimetabolite antifungals
- Examples
- MOA

Answer 6

-Flucytosine and griseofulvin

Inhibits the synthesis of nucleic acids by inhibiting enzymes such as NDA/RNA polymerase and topoisomerase
Inhibits replication and cell growth

Question 7

Discuss antifungals that inhibit glucan synthesis:
- Examples
- MOA

Answer 7

• Micafungin, caspofungin
• Inhibit the B- 1-3 glucan synthase which catalyses the conversion of glucose molecules into glycan
  Leads to osmotic instability