Antifungal Drugs Flashcards
what are yeasts
single- cell fungi
reproduced by budding
can be used for:
- baking breads
- brewing alcoholic beverages
what are moulds
- multicellular
- characterized by one, branching filaments called hyphae
what are the four types of myotic infections
- cutaneous
- subcutaneous
- superficial
- systemic (can be life-threatening, usually occurs in immunocompromised host).
Myoctic infections - Candida albicans
- may follow antibiotic therapy, antineoplastics, or immunosuppressants (corticosteroids)
- may result in overgrowth and systemic infections
- growth in the mouth is called thrush or oral candidiasis.
Common in newborn infants and immunocompromised patients
Mycotic infections - Vaginal candidaisis
- Yeast infection
- Pregnant women, women with diabetes, women taking oral contraceptives
what are antifungal drugs?
Medications used to treat infections caused by fungi, broken down into major groups based on their chemical structure.
types of systemic antifungal drugs
terbinafine, voriconazole
since the drugs are broken down into major groups based on their chemical structure what drugs are in TRIAZOLES?
Fluconazole, voriconazole
since the drugs are broken down into major groups based on their chemical structure what drugs are in ECHINOCANDINS?
Caspofungin
since the drugs are broken down into major groups based on their chemical structure what drugs are in IMIDAZOLES?
Ketoconazole (common topical)
since the drugs are broken down into major groups based on their chemical structure what drugs are in Poleynes?
Amphotericin B, nystatin
flucytosine
- Also known as 5-fluorocytosine (antimetabolite)
- Taken up by fungal cells; interferes with deoxyribonucleic acid (DNA) synthesis
- Result: fungal cell death
Older drug; newer drugs are more commonly used
griseofulvin
- Disrupts cell division
- Result: inhibited fungal mitosis (cell division)
- Older drug; newer drugs are more commonly used.
Polyenes: amphotericin B and nystatin
- Bind to sterols in cell membrane lining
- Result: fungal cell death
- Do not bind to human cell membranes or kill human cells
caspofungin
- Prevent the synthesis of glucans (essential components of fungal cell walls)
- Result: fungal cell death
what to use for systemic and topical fungal infections?
Amphotericin B
what does fluconazole do?
passes into the cerebrospinal fluid and inhibits the growth of cryptococcal fungi; effective in the treatment of cryptococcal meningitis
Contraindications for antifungal drugs
most common: drug allergy, liver failure, kidney failure, and porphyria (for griseofulvin)
itraconazole contrainidcations?
itraconazole: contraindicated treatment of onychomycoses in patients with severe cardiac problems
which can cause fetal harm in pregnant women?
Voriconazole
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, gastrointestinal upset, anemia
Amphotericin B Adverse Effects: Prevention
- Prescribers commonly order various premedications: antiemetics, antihistamines, antipyretics, and corticosteroids
- Prevent or minimize infusion-related reactions to amphotericin B
- Likelihood of such reactions can also be reduced by using longer-than-average drug infusion times (i.e., 2 to 6 hours)
what are the adverse effects of fluconazole?
Nausea, vomiting, diarrhea, stomach pain,
Increased liver enzymes
Use with caution in patients with kidney or liver dysfunction
what are the adverse effects of nystatin?
Nausea, vomiting, anorexia, diarrhea, rash, urticaria
Antifungal Drugs: Interactions
Many antifungal drugs are metabolized by the cytochrome P450 enzyme system.
- Co-administration of two drugs that are metabolized by this system may result in competition for these enzymes and thus higher levels of one of the drugs.
Nursing Implications (1 of 5)
Before beginning therapy, assess for hypersensitivity, possible contraindications, and conditions that require cautious use.
Obtain baseline vital signs, complete blood count, liver and renal function studies, and electrocardiogram.
Assess for other medications used (prescribed and over the counter), to avoid drug interactions
Some oral forms should be given with meals to decrease gastrointestinal upset; others require an empty stomach. Be sure to check.
Nursing implications 2 of 5
Monitor vital signs of patients receiving intravenous (IV) infusions every 15 to 30 minutes.
amphotericin B nursing implications?
To reduce the severity of the infusion-related reactions, pretreatment with an antipyretic (acetaminophen), antihistamines, antiemetics, and corticosteroids may be given.
Use IV infusion pumps and the most distal veins possible.
what to monitor for antifubgals?
Monitor therapeutic effects.
Easing of symptoms of infection
Improved energy levels
Normal vital signs, including temperature
Watch for and carefully monitor adverse effects.
