antifungal drugs Flashcards
what are the amphotericin drugs ?
amphotericin B
nsytatin
flucytosine
what is the sterol in fungus cell wall ?
ergosterol
what is the mechanims of amphotericin B ?
binds ergosterol
forms pores in the membrane
causes electrolyte leakage and cell death
what are the uses of amphocetrin B ?
systemic dissemented forms of fungal infections
only given IV or intra thecal
what are the side effects of amphocetrin B ?
1- fever and chills “ shake and bake”
2- phlebitis , pain of vein used for infusion
3- hypotension and arrythmia
4- nephrotoxicity
5- hypomagnesium and hypokalemia
6- normocytic anemia
how are the side effects of amphotericin tackled ?
the fever and chills - NSAIDS or tylenol
Phlebitis - avoided by using a central line
sometimes hydrocortisone is given with th infusion
nephrotoxicity - hydration , and the use of liposomal amphotericin B
always check electrolytes
what are the other renal complications associated with amphotericin B ?
1- distal type 1 renal tubular acidosis
2- nephrogenic diabetes insipidus
what is the mechanism of nystatin ?
the same as amphocetrin B where it attaches to ergosterol
what are the uses of nystatin ?
highly toxic when given as IV and is only used as the swish and swallow for thrush
also used for diapr rash
what type of fungal infection is nystatin ineffective against ?
dermatophytes ( keratin using fungus)
what is the mechanism of flucytosine ?
blocks fungal DNA and RNA synthesis
converted to 5 urofuracil only inside fungal cells
what are the uses of flucytosine ?
usually used as an amphocetrin B booster not usually used alone
main use is in cryptococccal meningits
what is the major side effect associated with flucytosine ?
bone marrow suppression
because there is spontaneous conversion into 5 FU and it starts acting like chemo
what is the mechanism of azole anti fungals ?
they block ergosterol synthesis by inhibiting P450 enzyme in fungi
what are the side effects associated with azoles ?
inhibits the livers p450 system
which increase the effect of warfarin and theophylline
what are the current uses of ketoconazole ?
sometimes used in cushing
blocks testosterone ( may cause gynecomastia )
what is the drug of choice for the treatment of dimorphic fungal pneumonias ?
itraconazole
what are the uses of fluconazole ?
good against cryptococcus
vulvovaginitis too
what ae the uses of clotrimazole ?
diaper rash
what are the uses of voriconazole ?
severe systemic fungal infections ( aspergillus)
what are the two echinocandins ?
capsofungin and micafungin
what is the function and mechanism for echinocandins ?
inhibit cell wall synthesis
block the synthesis of beta glucans
what are the two fungi that are treated by echinocandins ?
aspergillus
candidemia
what are the side effects of echinocandins ?
GI upset
histamine associated reaction
what is the mechanism of terbinafine ?
blocks squalene epoxidase
what are the uses of terbanifine ?
givern orally to treat dermatophyte infections especiallly onchomycosis
what are the side effects of terbinafine ?
headache
hepatotoxicity
blurry vision
what is the mechanism of griseofulvin ?
blocks mitosis by interfering with microtubules
what are the side effects of griseofulvin ?
induces p450 so warfarin and theophylline levels will fall
teratogenic
carcinogenic
what are the cases in which griseofulvin is not safe ?
not safe in pregnancy
not safe in porphyria
not safe in liver disease
what must be supplemented with the use of amphotericin B ?
supplemental potassium and magnesium
