Anti-fungal agents

Copyright © 2002, 1998, Elsevier Science (USA). All rights reserved.

Antifungal AgentsAntifungal Agents



Drugs used to treat infections caused by fungiDrugs used to treat infections caused by fungi

• Systemic and topicalSystemic and topical


FungiFungi

• Also known as mycosesAlso known as mycoses

• Very large and diverse group of Very large and diverse group of microorganismsmicroorganisms

• Broken down into yeasts and moldsBroken down into yeasts and molds


YeastsYeasts

• Single-cell fungiSingle-cell fungi

• Reproduce by buddingReproduce by budding

• Very useful organismsVery useful organisms

– BakingBaking

– Alcoholic beveragesAlcoholic beverages


MoldsMolds

• MulticellularMulticellular

• Characterized by long, branching filaments Characterized by long, branching filaments called hyphaecalled hyphae


Mycotic InfectionsMycotic Infections

Four General TypesFour General Types

• CutaneousCutaneous

• SubcutaneousSubcutaneous

• SuperficialSuperficial

• Systemic*Systemic*

*Can be life-threatening*Can be life-threatening

*Usually occur in immunocompromised host*Usually occur in immunocompromised host



Candida albicansCandida albicans

• Due to antibiotic therapy, antineoplastics, Due to antibiotic therapy, antineoplastics, or immunosuppressantsor immunosuppressants

• May result in overgrowth and systemic infectionsMay result in overgrowth and systemic infections



In the mouth:In the mouth:

• Oral candidiasis or thrushOral candidiasis or thrush

• Newborn infants and immunocompromised patientsNewborn infants and immunocompromised patients



Vaginal candidiasis:Vaginal candidiasis:

• ““Yeast infection”Yeast infection”

• Pregnancy, diabetes mellitus, oral contraceptivesPregnancy, diabetes mellitus, oral contraceptives



SystemicSystemic

• Examples: amphotericin B, fluconazole, Examples: amphotericin B, fluconazole, ketoconazole, itraconazoleketoconazole, itraconazole

TopicalTopical

• Examples: clotrimazole, miconazole, nystatinExamples: clotrimazole, miconazole, nystatin



Broken down into four major groups based Broken down into four major groups based on their chemical structureon their chemical structure

• Polyenes: amphotericin B and nystatinPolyenes: amphotericin B and nystatin

• FlucytosineFlucytosine

• Imidazoles: ketoconazole, miconazole, clotrimazole, Imidazoles: ketoconazole, miconazole, clotrimazole, fluconazolefluconazole

• GriseofulvinGriseofulvin


Antifungal Agents:Antifungal Agents:Mechanism of ActionMechanism of Action

Polyenes: amphotericin B and nystatinPolyenes: amphotericin B and nystatin

• Bind to sterols in cell membrane liningBind to sterols in cell membrane lining

• Allow K+ & Mg++ to leak out, altering fungal cell Allow K+ & Mg++ to leak out, altering fungal cell metabolismmetabolism

• Result: fungal cell deathResult: fungal cell death



flucytosineflucytosine

• Also known as 5-fluorocytosine (antimetabolite)Also known as 5-fluorocytosine (antimetabolite)

• Taken up by fungal cells and interferes with DNA Taken up by fungal cells and interferes with DNA synthesissynthesis




Imidazoles Imidazoles ketoconazole, miconazole, clotrimazole, fluconazoleketoconazole, miconazole, clotrimazole, fluconazole

• Inhibit an enzyme, resulting in cell membrane Inhibit an enzyme, resulting in cell membrane leakingleaking

• Lead to altered cell membraneLead to altered cell membrane




griseofulvingriseofulvin

• Disrupts cell divisionDisrupts cell division

• Result: inhibited fungal mitosis (reproduction)Result: inhibited fungal mitosis (reproduction)


Antifungal Agents: Side EffectsAntifungal Agents: Side Effects

amphotericin Bamphotericin B“Shake and Bake”“Shake and Bake”

feverfever chillschills headacheheadache anorexiaanorexia

malaisemalaise nauseanausea hypotensionhypotension tachycardiatachycardia

muscle and joint painmuscle and joint pain

lowered potassium and magnesium levelslowered potassium and magnesium levels

*renal toxicity*renal toxicity

*neurotoxicity: seizures and paresthesias*neurotoxicity: seizures and paresthesias


Antifungal Agents: Side EffectsAntifungal Agents: Side Effects

fluconazolefluconazole• nausea, vomiting, diarrhea, abdominal pain,nausea, vomiting, diarrhea, abdominal pain,• increased liver function studiesincreased liver function studies

flucytosineflucytosine• nausea, vomiting, anorexianausea, vomiting, anorexia

griseofulvingriseofulvin• rash, urticaria, headache, nausea, vomiting, anorexiarash, urticaria, headache, nausea, vomiting, anorexia


Antifungal Agents: Antifungal Agents: Nursing ImplicationsNursing Implications

• Before beginning therapy, assess for Before beginning therapy, assess for hypersensitivity, possible contraindications, hypersensitivity, possible contraindications, and conditions that require cautious use.and conditions that require cautious use.

• Obtain baseline VS, CBC, liver function Obtain baseline VS, CBC, liver function studies, and ECG.studies, and ECG.

• Assess for other medications used Assess for other medications used (prescribed and OTC) in order to avoid (prescribed and OTC) in order to avoid drug interactions.drug interactions.



• Follow manufacturer’s directions carefully Follow manufacturer’s directions carefully for reconstitution and administration.for reconstitution and administration.

• Monitor VS of patients receiving IV infusions Monitor VS of patients receiving IV infusions every 15 to 30 minutes.every 15 to 30 minutes.

• During IV infusions, monitor I & O and During IV infusions, monitor I & O and urinalysis findings to identify adverse urinalysis findings to identify adverse renal effects.renal effects.


Antifungal Agents: Antifungal Agents: Nursing ImplicationsNursing Implicationsamphotericin Bamphotericin B

• To reduce the severity of the infusion-related To reduce the severity of the infusion-related reactions, pretreatment with an antipyretic reactions, pretreatment with an antipyretic (acetaminophen), antihistamines, and antiemetics (acetaminophen), antihistamines, and antiemetics may be given.may be given.

• A test dose of 1 mg per 20 mL 5% dextrose inA test dose of 1 mg per 20 mL 5% dextrose inwater infused over 30 minutes should be given.water infused over 30 minutes should be given.

• Use IV infusion pumps and the most distal Use IV infusion pumps and the most distal veins possible.veins possible.



• Tissue extravasation of fluconazole at the IV Tissue extravasation of fluconazole at the IV site may lead to tissue necrosis—monitor IV site may lead to tissue necrosis—monitor IV site carefully.site carefully.

• Oral forms of griseofulvin should be given Oral forms of griseofulvin should be given with meals to decrease GI upset.with meals to decrease GI upset.

• Monitor carefully for side/adverse effects.Monitor carefully for side/adverse effects.



Monitor for therapeutic effects:Monitor for therapeutic effects:

• Easing of the symptoms of infectionEasing of the symptoms of infection

• Improved energy levelsImproved energy levels

• Normal vital signs, including temperatureNormal vital signs, including temperature

Anti-fungal agents

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