Chapter 49: Fungal Infections Flashcards
Fungal Infection characteristics
fungal infections not easily transmitted through casual contact
Love dark, moist environments and lots of sugar
serious fungal infections are uncommon in people with healthy immune defenses
treatment may require weeks to months of therapy
how do fungal infections affect immunocompromised pts
systemic fungal infections may be rapidly fatal
may experience frequent fungal infections and require aggressive pharmacotherapy
Mycoses can be classified as
- Superficial & subcutaneous - topical agents
- affect the scalp, skin, nails, and mucous membranes - Systemic - oral or parenteral medications
- affect internal organs (typically lungs, brain, digestive organs)
Antifungal drugs MOA
act by disrupting the fungal cell membrane or wall, affecting fungal enzymes or disrupting replication
Systemic Fungal Infections prototype
amphotericin B deoxycholate
amphotericin B deoxycholate uses
severe systemic mycoses
prophylactic antifungal therapy
amphotericin B deoxycholate MOA
binds to ergosterol in fungal cell membrane
Amphotericin B deoxycholate ADEs
acute fever
chills
vomiting
anorexia
headahce
phlebitis
potassium deficiency
electrolyte imbalance
Amphotericin B deoxycholate
Cardiac arrest
ototoxicity
nephrotoxicity
hepatotoxicity
anaphylaxis
blood abnormalities
dysrhythmias
Amphotericin B deoxycholate contraindications/precautions
blood urea nitrogen (BUN) 40mg/dL
serum creatinine above 3mg/dL
hypotension
hypokalemia
shock is medication administered to rapidly
Amphotericin B deoxycholate considerations
complete health Hx
perform infection-focused physical examination
premeditate with antipyretics, antihistamines, antiemetics, corticosteroids
perform baseline C&S tests prior to therapy
reduce or discontinue drug if BUN over 40mg/dL or serum creatinine over 3mg/dL
monitor cardio and resp status
check VS Q30 minutes for at least 4 hours after test dose
record I&O and weight
assess for erythema
administer IV over 2-6 hours
observe for injection sit for inflammation or thrombosis
assess for ototoxicity an immediately report any hearing loss or tinnitus, vertigo, or unsteady gait
General fungal infection
Azoles
Azoles
Largest and most versatile group of antifungals
broad spectrums
can be administered PO and have superior safety profile
Two chemical classes of azaleas
Imidazoles
Triazoles
Categorization of azoles by utility
systemic agents
topical agents
some agents used for systemic and topical
Systemic azoles
spectrum similar to amphotericin B
less toxic
administered PO
ADEs: N/V in 10-20% of pts
Azole prototype:
Fluconazole
Fluconazole Uses
Candida albicans
cryptococcal meningitis
mycoses resistant to other antifungals
Fluconazole MOA
interferences with synthesis of ergosterol
Fluconazole ADEs
N/V/D
Fluconazole Serious ADEs
SJS in immunosuppressed patients
Fluconazole contraindications
hypersensitivity to the drug or another azole
hepatic impairment
hypokalemia
pre existing renal impairment
Fluconazole considerations
monitor BUN, serum creatinine, and liver function lab tests
assess for hepatotoxicity
fluconazole treatment of OD
no specific therapy
dialysis to lower serum drug level
Superficial fungal infections
superficial anti fungal drugs safer than systemic counterparts
many are available as over the counter (OTC) creams, gels, and ointments
may take weeks to months to treat
sometimes used with PO to treat extensive
Dematomycoses
- Tinea corporis (ringworm)
- Tine curries (jock itch)
- Tinea pedis (athletes foot)
- Tinea capitis (head, eyebrows, eyelashes infected)
Onychomycosis (tine unguium)
infection of the nail
Superficial candidasis
oropharyngeal candidasis (thrush)
Superficial prototype drug
Nystatin
nystatin uses
candida infections of vagina skin mouth throat and GI
nystatin MOA
binds to sterols in the fungal cell membrane
allows leakage of intracellular content across the weakened membrane
nystatin ADEs
minor skin irritation and burning
contact dermatitis
D/N/V
nystatin contraindications/precautions
hypersensitivity to the drug
pregnancy and lactation
cream/topicals (Cat B)
Oral suspension or tablets (Cat C)
Nystatin Drug interactions
unknown
Nystatin treatment if OD
symptomatic
Nystatin considerations
Hx and assessment
avoid occlusive dressing or ointment on moist, dark areas of the body
teach pt to avoid sharing towels, shoes, or personal objects
Griseofulvin
Drugs similar to nystatin
used to treat skin infections such as jock itch athletes foot and ringworm, fungal infections of scalp, fingernails and toenails
Griseofulvin SE
phytotoxicity, , urticaria, dizziness, decreased OCP, alcohol = disrulfiram
