Chapter 96: Antifungal Agents

Question 1

What is mycosis?

Answer 1

disease caused by infection with a fungus

Question 2

Two major groups of antifungals

Answer 2

systemic mycotic infections
superficial mycotic infections

Question 3

Systemic mycotic infections

Answer 3

opportunistic (patient with compromised immune system)
non-opportunistic (can occur in anyone)

Question 4

Superficial mycotic infections

Answer 4

candidiasis: (mucous membranes and moist skin usually - mouth, throat, gut, and vagina)
dermatophytes: (requires keratin for growth - skin, hair, nails)

Question 5

Amphotericin B
MOA

Answer 5

broad spectrum fungal agent - binds to ergosterol in cell membrane

Question 6

Amphotericin B high or low toxicity

Answer 6

high toxicity
infusion reaction and renal damage occurs in many patients
must be given IV; no oral administration
infuse slowly over 2-4 hours

Question 7

Amphotericin B uses

Answer 7

drug of choice for systemic mycoses

Question 8

Amphotericin B Adverse Effects

Answer 8

Infusion Reactions
Nephrotoxicity (check kidney function weekly, monitor I/O, reduce drug if creatinine >3-5 mg/dl)
Hypokalemia (may need potassium supplements, kidney)
Phlebitis

Question 9

Describe the cause, s/s, time of onset, and intensity for amphotericin related infusion rxns

Answer 9

Fever, chills, rigors, nausea, and headache
Caused by release of pro-inflammatory cytokines
Symptoms begin 1 to 3 hours after start of infusion and last for about 1 hour
Less intense with lipid-based amphotericin B formulations

Question 10

What 4 treatments are given for mild infusion reactions of Amphotericin B?

Answer 10

Diphenhydramine + acetaminophen (Aspirin can help but may increase renal damage)
IV meperidine or dantrolene can be given if rigors occur
Hydrocortisone can be given with caution

Question 11

IMPORTANT TO KNOW about Amphotericin B infusion

Answer 11

Amphotericin infusion produces a high incidence of phlebitis; this can be minimized by changing peripheral venous sites often, administering amphotericin through a large central vein, and pretreatment with heparin

Question 12

IV considerations for Amphotericin B

Answer 12

Test Close (start low, go slow to see if patient reacts poorly)
Check for precipitate (medication cen “clump up” in IV bag over time)
Assess for phlebitis (prolonged (repeated) admin not recommended in any on access site)
Individualized dosing (difficult to standardize due to varied reactions)

Question 13

Azoles

Answer 13

broad spectrum antifungal drugs (damages cytoplasmic membrane/disrupts cell integrity)
Alternative to amphotericin B for most systemic mycosis
lower toxicity
can be given orally

Question 14

Azoles disadvantages

Answer 14

inhibit P450 drug-metabolizing enzymes and can increase levels of many other drugs

Question 15

Fluconazole (Diflucan)

Answer 15

azole group of antifungal agents
fungistatic (disrupts integrity of cytoplasmic membrane)
good oral absorption (IV and PO dosage the same)
1x/day with or without food

Question 16

Fluconazole (Diflucan) Adverse Effects

Answer 16

Nausea
Headache
Vomiting
Abdominal Pain
Diarrhea
Hapatotoxicity - rare