MOA
Which antifungal Binds ergosterol ⇒ Pores in membrane ⇒ Osmotic lysis
amphotericin B (nystatin has same MOA)
Why is Amphotericin B so toxic to humans?
AmphoB is poorly selective for ergosterol over cholesterol
(∴ It significantly damages human cell membranes)
Adverse Effects (2) : Voraconazole
(1) Blurry vision with flashes of light
(2) Changes in color vision (what other antibiotic and antiarrhythmic does this?)
activates or inhibits CYP-450?
activates
(SCRAP GPS mnemonic)
Incorporates into DNA/RNA ⇒ Halts DNA and protein synthesis
Flucytosine (active form is 5-Flourouracil)
Adverse Effects - Unrelated to kidneys (4) : Amphotericin B
(1) Infusion reaction ⇒ Hypotension
(2) "Shake and bake" chills
(3) Seizures
(4) Thrombophlebitis
Name 2 first line treatments for invasive asperillosis
(1) Echinocandins
(2) Voraconazole
(Amphotericin B is used for angioinvasive aspergillosis)
Treatment (2) : Tinea capitis, onychomycosis
(1) Griseofulvin
(2) Terbinafine
(Note: Griseofulvin is fungistatic whereas Terbinafine is fungicidal)
Inhibits conversion of Lanosterol → Ergosterol
Azoles
Adverse Effects - Related to kidney (4) : Amphotericin B
(1) Type I renal tubular acidosis
(2) ⇒ Hypokalemia
(3) & ⇒ Mg2+ wasting
(4) ↓ EPO ⇒ Anemia
Which systemic antifungal is used to treat mucocutaneous candidiasis?
Fluconazole
(Whereas Nystatin is the TOPICAL antifungal which is used)
Adverse Effects (2) : Terbinafine
(1) GI distress
(2) Hepatotoxicity
Binds microtubules ⇒ Halts mitosis
Griseofulvin
What is the topical treatment for oropharyngeal candidiasis?
nystatin mouth rinse(same MOA as ampho B)
Which azole is used to treat infections by dimorphic fungi?
Itraconazole (sporothrix/sporotrichosis)
IV for systemic candidal infections
echinocandins
1: Inhibits squalene epoxidase
2: Inhibit synthesis of β-1,3-glucan
1: terbinafine
2: echinocandins
Name 2 methods used to reduce the toxicity of Amphotericin B
(1) Liposomal formulation
(2) Volume expansion with saline prior to adminstration
(Liposomal formulation ⇒ Reduced affinity for human cholesterol)
Name 2 azoles used to treat tinea infections
(1) Clotrimazole
(2) Miconazole
What type of infections is Griseofulvin/terbinafine used to treat?
dermatophytic infections