C4 Flashcards
1
Q
Antifungal drugs?
9
A
- Clot.RimaZol (ريما)
- Fluconazol
- Itraconazol
- Voriconazol
- Caspofungin (فنجان)
- Flucytosin
- Terbinafine
- Nystatin
- Amphotericin B
2
Q
what about Amphotericin B?
A
Amphotericin B is a polyene Abx related to nystatin
3
Q
Amphotericin B PharmacoKinetix?
A
- dministered I.V. in 3 forms poorly (absorbed from G.I.T):
1. nonlipid colloidal suspension
2. lipid complex
3. liposomal formulation - distribution: all tissues (except CNS)
- Elimination: slow hepatic metabolism
( a bit in urine) - 1/2 life: ± weeks
-
4
Q
Amphotericin MOA?
A
- fungicidal
- affect the permeability and transport
properties of fungal membranes - bind to Ergosterol (cell membranes)
–> artificial pores - Resistance: uncommon, occurs if membrane ergosterol level or structure decrease
5
Q
Amphotericin B Clinical uses?
A
- treatment of systemic mycoses
- used for initial induction regimens before Azole
- widest Antifungal spectrum
- drug of choice, or codrug of choice, for most systemic infections caused by (Aspergillus, C.Albicans, Cryptococcus)
- given by slow I.V.
6
Q
Amphotericin Toxicity?
A
infusion related
doe limiting
Neurotoxicity
7
Q
Amphotericin B I.V. Infusion related toxicity?
A
- fever
- chills
- muscle spasms
- vomiting
- shock-like fall in blood pressure
- effects can be attenuated by: slow infusion rate and premedication with antihistamines, antipyretics, glucocorticoids*
8
Q
Amphotericin B dose limiting toxicity?
A
- decreases the glomerular filtration rate + renal tubular acidosis (with magnesium and potassium wasting)
- Anemia: decrease of erythropoietin formation
- Liposomal formulations have reduced nephrotoxic effects
9
Q
Amphotericin B Neurotoxicity toxicity?
A
Intrathecal administration –> seizures and neurologic damage
10
Q
what about Flucytosine?
A
pyrimidine antimetabolite related to the anticancer 5-FU
11
Q
Flucytosin PharmacoKinetix?
A
- Bioavailability: effective orally
- distribution: most body (also CNS)
- Elemination: intact in the urine
(dose must be reduced in patients with renal impairment)
12
Q
Flucytosine MOA?
A
- membrane permease –> accumulate the drug in fungal cells –> cytosine deaminase –> 5-FU –> inhibits thymidylate synthase
- Resistance can occur rapidly if flucytosine is used alone
- When 5-FC is given with amphotericin B/ itraconazole –> emergence of resistance is decreased and synergistic antifungal effects may occur
13
Q
Flucytosine clinical uses?
A
- antifungal spectrum of 5-FC is narrow
- limited to the treatment in combination with amphotericin B / itraconazole
- used against:
1. Cryptococcus neoformans
2. molds (for chromoblastomycosis)
14
Q
Flucytosine Toxicity?
A
- Prolonged high plasma LvLs:
1. reversible bone marrow depression
2. alopecia
3. liver dysfunction.
15
Q
Azole Antifungal agents?
FIV(5)
A
- Fluconazol
- Itraconazol
- Voriconazol