Antifungal Agents Flashcards
Amphotericin MoA?
binds ergosterol –> forming pores in membranes with loss of vital intracellular constituents
Nystatin MoA?
[same as Amphotericin]
binds ergosterol –> forming pores in membranes with loss of vital intracellular constituents
Amphotericin Pharmacokinetics?
- IV or topical only
- Slow excretion by kidney & hepato-biliary
- 1/2 life = 15 d
Amphotericin Spectrum
broad spectrum!!
- life threatening
- systemic infection
Amphotericin Adr?
- Nephrotoxicity
- acute fever/chill
- Anemia
Nystatin Pharmacokinetics?
Topical only!!
NO orally absorption
Nystatin Spectrum
Superficial Candidal infection
Nystatin Adr?
- Topically: well-tolerated
2. Oral: mild GI upset
Caspofungin MoA?
inhibits synthesis of cell wall component
–> disrupting assembly
Caspofungin Pharmacokinetics?
IV only!!
How P450 inducers affect Caspofungin?
decreasing level
Caspofungin spectrum?
aspergillosis (infection with aspergillus), if resistant to ampho B
Caspofungin Adr?
infusion related symptoms
* histamine –> rash, pruritus, n/v
Triazoles MoA?
[like imidazole]
* inhibit P450 ergosterol synthesis –> altering membrane permeability
How Triazole comparing with Imidazole?
more selective inhibition of fungal P450
Representing Triazole drug?
- Fluconazole
- Intraconazole
- Terconazole
Fluconazole Pharmacokinetics?
- IV/po
- renal excretion
- enter CNS
Fluconazole Spectrum
- oropharyngeal/esophageal candidiasis
2 vulvovaginal candidiasis (single dose) - cryptococcal meningitis
Fluconazole Adr?
- GI upset : well-tolerated
2. Lesser effect on CYP450 metabolism
Intraconazole Pharmacokinetics?
- IV/po
2. hepatic metabolism
Intraconazole Spectrum?
- superficial dermatophytosis
2. onychomycosis
Intraconazole Adr?
- inhibits CYP450 metabolism
2. n/v, diarrhea, headache
Terconazole Pharmacokinetics?
Topical only
Terconazole Spectrum?
vulvovaginal candidiasis
Terconazole Adr?
None
Imidazole MoA?
inhibit CYP450 ergosterol synthesis –> altering membrane permeability
Imidazole representing drug?
- Ketoconazole
2. Clotrimazole/Miconazole
Ketoconazole Pharmacokinetics?
- IV/po/topical
2. Hepatic metabolism
Ketoconazole Spectrum?
- System infection (candidiasis)
2. wide use in dermatologic indications
Why Ketoconazole use for systemic treatment declines?
Due to toxicity
Ketoconazole Adr?
- Hepatotoxicity, anorexia, n/v
- Inhibits CYP450
- Inhibits Androgen-GC biosynthesis
Clotrimazole Pharmacokinetics?
Topical only
Clotrimazole Spectrum?
Oral & vaginal candidiasis
Clotrimazole Adr?
None
Terbinafine MoA?
inhibits squalene oxidase reducng ergosterol synthesis
Terbinafine Pharmacokinetics?
- po & topical
2. Metabolized by P450
Terbinafine Spectrum
- po: onychomycosis of finger/toe nails
2. topical: athlete’s foot
Terbinafine Adr?
- Inhibition CYP450
2. headache, diarrhea, rash
Flucytosine MoA?
converted to 5FU in fungi –> inhibit thymidylate synthetase & DNA synthesis
Flucytosine Pharmacokinetics?
- well-absorbed & distributed
2. renal elimination –> decrease dose if renal impair
Flucytosine Spectrum?
cryptococcosis & candidiasis serious infections
Flucytosine Adr?
- n/v, skin rashes
2. prolonged use –> bone marrow depression
Griseofulvin MoA?
binds to fungal microtubules inhibiting mitosis
Griseofulvin Pharmacokinetics?
- po: poor
- -> improving with: microsizing particle, fatty meal
Griseofulvin Spectrum?
Severe dermatophytosis of skin, hair, finger/toe nails
Griseofulvin Adr?
- hypersensitivity reactions
2. GI distress, headache, confusion