Antifungals

Question 1

Fungi

Answer 1

Very large and diverse group of microorganisms; includes yeasts and moulds

Fungal infections are also known as mycoses.

Some fungi are part of the normal flora of the skin, mouth, intestines, and vagina.

Systemic, cutaneous, subcutaneous, and superficial

Cutaneous, subcutaneous, and superficial: infections of various layers of the integumentary system (skin, hair, or nails)

Fungi that cause integumentary infections are known as dermatophytes.

Dermatomycoses

Question 2

Yeasts

Answer 2

Single-cell fungi

Reproduce by budding

Can be used for:
Baking breads
Brewing alcoholic beverages

Question 3

Moulds

Answer 3

Multicellular

Characterized by long, branching filaments called hyphae

Question 4

Mycotic Infections 4 types

Answer 4

Cutaneous

Subcutaneous

Superficial

Systemic
-Can be life threatening
-Usually occur in immunocompromised host

Question 5

Mycotic Infections : Candida albicans

Answer 5

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

Question 6

Mycotic Infections : Vaginal candidiasis

Answer 6

Yeast infection

Pregnant women, women with diabetes, women taking oral contraceptives

Question 7

Antifungal Drugs

1. Define
2. 2 types

Answer 7

Medications used to treat infections caused by fungi

Systemic and Topical

Question 8

Antifungal Drugs

Systemic

Answer 8

Systemic:

terbinafine, and voriconazole

amphotericin B, caspofungin, fluconazole, itraconazole, isavuconazole, ketoconazole, micafungin sodium, nystatin, posaconazole, anidulafungin, ravuconazole (in clinical III trials)

Question 9

Antifungal Drugs

Triazoles

Answer 9

fluconazole
voriconazole

Question 10

Antifungal Drugs

Echinocandins

Answer 10

caspofungin

Question 11

Antifungal Drugs

Imidazoles

Answer 11

ketoconazole (common topical)

Question 12

Antifungal Drugs

Polyenes

Answer 12

amphotericin B, nystatin

Question 13

flucytosine

Answer 13

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

Question 14

griseofulvin

Answer 14

Disrupts cell division

Result: inhibited fungal mitosis (cell division)

Older drug; newer drugs are more commonly used.

Question 15

Polyenes: amphotericin B and nystatin

Answer 15

Bind to sterols in cell membrane lining

Result: fungal cell death

Do not bind to human cell membranes or kill human cells

Question 16

Imidazoles and triazoles: ketoconazole, fluconazole, itraconazole, voriconazole

Answer 16

Inhibit fungal cell cytochrome P450 enzymes, resulting in cell membrane leaking

Result: altered cellular metabolism and fungal cell death

Question 17

Echinocandins: caspofungin, micafungin, and anidulafungin

Answer 17

Prevent the synthesis of glucans (essential components of fungal cell walls)

Result: fungal cell death

Question 18

Antifungal drugs indications

Answer 18

Systemic and topical fungal infections

Drug of choice for the treatment of many severe systemic fungal infections is amphotericin B.

Choice of drug depends on type and location of infection

fluconazole: passes into the cerebrospinal fluid and inhibits the growth of cryptococcal fungi; effective in the treatment of cryptococcal meningitis

Question 19

Antifungal Drugs: Contraindications

Answer 19

Most common: drug allergy, liver failure, kidney failure, and porphyria (for griseofulvin)

itraconazole: contraindicated treatment of onychomycoses in patients with severe cardiac problems

voriconazole can cause fetal harm in pregnant women.

Question 20

Amphotericin B Adverse Effects

Answer 20

Cardiac dysrhythmias

Neurotoxicity; tinnitus; visual disturbances; paresthesias; convulsions

Kidney toxicity, potassium loss, hypomagnesemia

Pulmonary infiltrates

Fever, chills, headache, nausea, occasional hypotension, gastrointestinal upset, anemia

Question 21

Amphotericin B Adverse Effects: Prevention

Answer 21

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)

Question 22

Antifungal Drugs: Adverse Effects

fluconazole (Diflucan)

Answer 22

Nausea, vomiting, diarrhea, stomach pain,
Increased liver enzymes

Use with caution in patients with kidney or liver dysfunction

Question 23

Antifungal Drugs: Adverse Effects

nystatin (topical)

Answer 23

Nausea, vomiting, anorexia, diarrhea, rash, urticaria

Question 24

Antifungal Drugs: Additional Contraindications

Answer 24

Liver failure
Renal failure
Porphyria (griseofulvin)
Drug allergy
Pregnancy (voriconazole)

Question 25

Antifungal Drugs: Interactions

Answer 25

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.

Question 26

Nursing Implications

Answer 26

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. Follow the manufacturer’s directions carefully for reconstitution and administration. During IV infusions, monitor input and output to identify adverse effects. Some oral forms should be given with meals to decrease gastrointestinal upset; others require an empty stomach. Be sure to check. Monitor therapeutic effects. -Easing of symptoms of infection -Improved energy levels -Normal vital signs, including temperature Watch for and carefully monitor adverse effects.

Question 27

Monitor vital signs of patients receiving intravenous (IV) infusions every?

Answer 27

every 15 to 30 minutes.

Question 28

amphotericin B nursing implications

Answer 28

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.