antifungal drugs Flashcards
fungal infections are also known as
mycoses
infections of integumentary system
cutaneous
subcutaneous
superficial
fungi that causes integumentary infections are known as
dermatophytes
yeasts
- single cell fungi
- reproduce by budding
- can be used for baking bread and brewing alcohol
moulds
- multicellular
- long branching filaments called hyphae
4 general types of mycotic infections
- cutaneous
- subcutaneous
- superficial
- systemic (life threatening, usually in immunocompromised host)
candida albicans
- may follow antibiotic therapy, antineoplastics or immunosuppressants
- may result in overgrowth and systemic infections
- common in newborn infants and immunocompromised pts
candida albicans growth in mouth
thrush or oral candidiasis
vaginal candidiasis
- yeast infection
- pregnant women, women with diabetes, women taking oral contraceptives
aspergillosis infection affects the
lungs
meds used to treat systemic fungal infections
- terbinafine and voriconazole
triazoles
fluconazole, voriconazole
echinocandins
caspofungin
imidazoles
ketoconazole (common topical)
polyenes
amphotericin B, nystatin
polyenes (amphotericin B and nystatin) moa
- binds to steroles in cell membrane lining
- results in fungal cell death
- dont bind to human cell membranes or kill human cells
how to take nystatin
-swish and swallow and dont eat after for 30 mins
imidazoles and triazoles (ketoconazole, fluconazole and voriconazole )
- inhibits fungal cell cytochrome P450 enzymes resulting in cell membrane leaking
- result is altered cellular metabolism and fungal cell death
echinocandins (caspofungin) moa
- prevents synthesis of glucans (part of cell wall)
- results in fungal cell death
- adverse effect: hypotension
drug of choice for severe systemic fungal infections
amphotericin B
which drug is used to treat onychomycosis (fungal infection of fingernails and toenails)
terbinafine (Lamisil)
fluconazole passes through the ____
-cerebrospinal fluid and inhibits growth of crytococcal fungi
which drug is effective in the treatment of cryptococcal meningitis
fluconazole
antifungal contraindications
- allergy, liver failure, kidney failure and porphyria (for griseofulvin)
- itraconazole= cardiac issues
- voriconazole= preg
itraconazole contraindications
contraindicated in treatment of onychomycoses in pts with severe cardiac problems
voriconazole can cause
fetal harm in pregnant women
amphotericin B adverse effects
- cardiac dysrhythmias
- neurotoxicity ( tinnitus, visual disturbances, paresthesias, convulsions)
- kidney toxicity ( potassium loss, hypomagnesemia)
-pulmonary infiltrates - fever, chills, headache, nausea, occasional hypotension, GI upset, anemia
amphotericin B contraindications
bone marrow suppression and kidney impairment
amphotericin B adverse effects prevention
- premedications (antiemetics, antihistamines, antipyretics, corticosteroids)
- minimize infusion related reactions
- reactions can be reduced by using longer than average drug infusion times (2-6 hrs)
fluconazole adverse effects
- nausea, vomiting, diarrhea, stomach pain
- increased liver enzymes
use fluconazole with caution in
pts with kidney or liver dysfunction
nystatin (topical) adverse effects
nausea, vomiting, diarrhea, anorexia, rash, urticaria
antifungal interactions
- co administration of 2 drugs metabolized by the P450 enzyme may result in competition for this enzyme resulting in higher levels of one of these drugs
what to obtain from pt before antifungal administration
vitals, complete blood count, liver and renal function studies, electrocardiogram
how often to monitor vitals when receiving IV infusions (amphotericin B)
every 15-30 mins
amphotericin B preferred route
IV infusion pumps and the most distal veins
voriconazole is given
1 hr before or after meals
