Antifungal agents

• What are the main classifications of anti-fungal agents?

  Cell membrane inhibitors, cell wall inhibitors, and antimetabolites

  
• What are the types of cell membrane inhibitors in anti-fungal agents?

  • Polyenes
  • Azoles
  • Terbinafine

  
• What are the types of cell wall inhibitors in anti-fungal agents?

  • Echinocandins
• What are the antimetabolites used in anti-fungal treatment?

  • Fluorouracil
• What structural feature do polyenes possess?

  A macrocyclic ring with one lipophilic side and one hydrophilic side
• How do polyenes affect fungal cells?

  They bind to ergosterol, increasing membrane permeability and causing cell death

  
• What is Amphotericin B derived from?

  Streptomyces nodosus
• What is the primary action of Amphotericin B?

  It binds to ergosterol in fungal cell membranes

  
• How does Amphotericin B form pores in the fungal membrane?

  Multiple molecules orient themselves to create a micropore
• What is the drug of choice for aspergillosis?

  Amphotericin B
• What are the formulations of Amphotericin B?

  • Conventional Amphotericin B deoxycholate (toxic)
  • Liposomal amphotericin B (expensive)
  • Amphotericin B colloidal dispersion
  • Amphotericin B lipid complex
• What is Nystatin used for?

  Topical treatment of candidiasis
• How do azoles function in antifungal treatment?

  They inhibit C-14 α-demethylase, blocking ergosterol synthesis

  
• What are the two groups of azoles?

  • Imidazoles
  • Triazoles
• What is Clotrimazole used to treat?

  Vaginal candidiasis
• What formulation does Miconazole come in?

  Gels
• What is the use of Ketoconazole?

  Treatment of systemic mycosis and prophylaxis in immunosuppressed patients
• What is Fluconazole active against?

  Candida spp, except C krusei, and other fungi
• What is Itraconazole effective against?

  Yeast, moulds, and dimorphic fungi
• What is the significance of Posaconazole's affinity to P450?

  It has greater activity against most fungi
• What is Terbinafine's mechanism of action?

  It inhibits cell membrane function by acting as a structural analogue of squalene
• What is the effect of Terbinafine on ergosterol levels?

  It causes a decrease in ergosterol in the fungal cell membrane
• What are the effects of Echinocandins on fungal cells?

  • Disrupts fungal cell wall
  • Leads to osmotic instability and cell death
  • Inhibits 1,3-beta glucan synthase
• What is Caspofungin active against?

  Candida spp and Aspergillus
• What is the primary use of Anidulafungin?

  Active mainly on Candida spp
• What is Flucytosine classified as?

  A pyrimidine antimetabolite
• How does Flucytosine disrupt DNA synthesis?

  It inhibits thymidylate synthase
• What is Griseofulvin's mechanism of action?

  It disrupts cellular microtubules
• What is the primary use of Griseofulvin?

  Treatment of tinea capitis in children
• What are the strengths and weaknesses of the different antifungal agents discussed?

  Strengths:

  • Target specific fungal components
  • Various formulations available

  
  

  Weaknesses:

  • Potential toxicity (e.g., Amphotericin B)
  • Resistance development
  • Side effects vary by agent