Exam 3 - Antifungals

Question 1

nystatin

Answer 1

• class: polyene
• indications: treatment of superficial candida infections of mouth (thrush), oral mucosa, vagina, and skin
• available in creams, powder, topical, vaginal
• too toxic for IV
• SE: not a lot, mild skin irritation. oral: n/v/d, poor go absorption

Question 2

amphotericin B

Answer 2

• polyene anti-fungal
• MOA: binds to ergosterol in fungal cell membranes and causes them to become leaky and destroys cell wall of the fungus
• indications: agent of choice for most systemic mycoses
• route: PO or IV
• HIGH ALERT DRUG

Question 3

IV administration of amphotericin B

Answer 3

• must be diluted and infused slowly
• monitor BUN and creatinine
• must be on cardiac monitor
• give every other day for several months
• pre-treatment: with diphenhydramine, acetaminophen, or aspirin may decrease infusion symptoms (fever, pain, nausea, h/a)
• synergistic effect when given with flucytosine

Question 4

flucytosine

Answer 4

• class: pyrimidine
• MOA: inhibits fungal DNA synthesis
• indications: allows for a lower dose of amphotericin B to be used
• helps to decrease SE related to amphotericin

Question 5

azoles

Answer 5

• fluconazole
• MOA: interrupts the integrity of the cell wall by interfering with the synthesis of ergosterol
• indications: used for both superficial and less serious systemic fungal infections
• SE: topical - may cause redness, burning, itching
  systemic - severe GI upset, liver toxicity
• administration: take with food; oral, separate at least 2 hours from antacids or drugs that decrease stomach acid

Question 6

fluconazole

Answer 6

• advantages: rapidly and completely absorbed when given orally
• disadvantages: narrow spectrum, many drug interactions (CYP450 pathway)
• nursing implications: do not mix IV fluconazole with other meds; monitor coags for pts on warfarin; watch for hypoglycemia for pts with sulfonlureas; increases haldol and dilantin levels

Question 7

grisefulvin

Answer 7

• misc agent
• inexpensive older agent
• MOA: inhibits fungal mitosis - bings to keratin
• SE: bone marrow suppression, rash, CNS changes, n/v/d, anorexia
• indications: resistant dermatophyte infection of scalp, skin, and nails