Module 9 14 Antifungals Flashcards
(352 cards)
1
Q
Answer
A
Question
2
Q
What are the two major categories of antifungal agents?
A
Antifungal agents are categorized into drugs for systemic mycoses and drugs for superficial mycoses.
3
Q
What distinguishes systemic mycoses from superficial mycoses in terms of frequency and severity?
A
Systemic mycoses are less frequent but more severe than superficial mycoses.
4
Q
What is the primary focus of this summary regarding antifungal therapy?
A
This summary primarily focuses on the therapy of systemic mycoses.
5
Q
What are the two categories of systemic mycoses?
A
Systemic mycoses are categorized into opportunistic and nonopportunistic infections.
6
Q
Who is primarily affected by opportunistic mycoses?
A
Opportunistic mycoses, including candidiasis, aspergillosis, cryptococcosis, and mucormycosis, primarily affect debilitated or immunocompromised individuals.
7
Q
Which individuals can be affected by nonopportunistic mycoses?
A
Nonopportunistic mycoses, such as sporotrichosis, blastomycosis, histoplasmosis, and coccidioidomycosis, can affect any host but are relatively uncommon.
8
Q
Why is treating systemic mycoses challenging?
A
Treating systemic mycoses can be challenging because these infections often resist treatment and may require prolonged therapy with potentially toxic drugs.
9
Q
Where can you find information on the drugs of choice for systemic mycoses?
A
Table 79.1 provides a list of the drugs of choice for systemic mycoses.
10
Q
What are the four classes of systemic antifungal drugs?
A
The four classes of systemic antifungal drugs are polyene antibiotics, azoles, echinocandins, and pyrimidine analogs.
11
Q
What are the causative organisms for aspergillosis?
A
Aspergillosis is caused by Aspergillus spp.
12
Q
What is the drug of choice for aspergillosis?
A
The drug of choice for aspergillosis is voriconazole.
13
Q
What are the alternative drugs for treating aspergillosis?
A
Alternative drugs for aspergillosis include amphotericin B, isavuconazonium, itraconazole, posaconazole, caspofungin, and micafungin.
14
Q
What is the causative organism for blastomycosis?
A
Blastomycosis is caused by Blastomyces dermatitidis.
15
Q
What are the drugs of choice for treating blastomycosis?
A
The drugs of choice for blastomycosis are amphotericin B or itraconazole.
16
Q
Is there an alternative recommended treatment for blastomycosis?
A
No alternative treatment is recommended for blastomycosis.
17
Q
What is the causative organism for candidiasis?
A
Candidiasis is caused by Candida spp.
18
Q
What are the drugs of choice for treating candidiasis?
A
The drugs of choice for candidiasis are amphotericin B or fluconazole, either one, with or without flucytosine.
19
Q
What are the alternative drugs for treating candidiasis?
A
Alternative drugs for candidiasis include itraconazole, voriconazole, and caspofungin.
20
Q
What is the causative organism for coccidioidomycosis?
A
Coccidioidomycosis is caused by Coccidioides immitis.
21
Q
What are the drugs of choice for treating coccidioidomycosis?
A
The drugs of choice for coccidioidomycosis are amphotericin B or fluconazole.
22
Q
What are the alternative drugs for treating coccidioidomycosis?
A
Alternative drugs for coccidioidomycosis include itraconazole and ketoconazole.
23
Q
What is the causative organism for cryptococcosis?
A
Cryptococcosis is caused by Cryptococcus neoformans.
24
Q
What are the drugs of choice for treating cryptococcosis?
A
The drugs of choice for cryptococcosis are amphotericin B with or without flucytosine.
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What is the drug used for chronic suppression of cryptococcosis?
For chronic suppression of cryptococcosis, fluconazole is the drug of choice.
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What is the causative organism for histoplasmosis?
Histoplasmosis is caused by Histoplasma capsulatum.
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What are the drugs of choice for treating histoplasmosis?
The drugs of choice for histoplasmosis are amphotericin B or itraconazole.
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What are the alternative drugs for treating histoplasmosis?
Alternative drugs for histoplasmosis include fluconazole and ketoconazole.
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What is the drug used for chronic suppression of histoplasmosis?
For chronic suppression of histoplasmosis, itraconazole is the drug of choice.
30
What is the causative organism for mucormycosis?
Mucormycosis is caused by Mucor.
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What is the drug of choice for treating mucormycosis?
The drug of choice for mucormycosis is amphotericin B.
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What is the alternative drug for treating mucormycosis?
The alternative drug for mucormycosis is isavuconazonium.
33
What is the causative organism for sporotrichosis?
Sporotrichosis is caused by Sporothrix schenckii.
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What are the drugs of choice for treating sporotrichosis?
The drugs of choice for sporotrichosis are amphotericin B or itraconazole.
35
What is the alternative drug for treating sporotrichosis?
The alternative drug for sporotrichosis is fluconazole.
36
How are the systemic antifungal drugs classified?
Systemic antifungal drugs are classified into polyene antibiotics, azoles, echinocandins, and pyrimidine analogs.
37
What is the mechanism of action of polyene antibiotics in treating fungal infections?
Polyene antibiotics bind to ergosterol and disrupt the fungal cell membrane.
38
Name a representative drug from the polyene antibiotic class used to treat fungal infections.
Amphotericin B is a polyene antibiotic used to treat fungal infections.
39
What is the mechanism of action of azoles in treating fungal infections?
Azoles inhibit the synthesis of ergosterol and disrupt the fungal cell membrane.
40
Provide examples of azole drugs used to treat fungal infections.
Azole drugs used to treat fungal infections include fluconazole, isavuconazonium, itraconazole, ketoconazole, posaconazole, and voriconazole.
41
How do echinocandins work in the treatment of fungal infections?
Echinocandins inhibit the synthesis of β-1,3-d-glucan and disrupt the fungal cell wall.
42
Name some representative drugs from the echinocandin class used for fungal infection treatment.
Representative drugs from the echinocandin class include anidulafungin, caspofungin, and micafungin.
43
What is the mechanism of action of pyrimidine analogs in treating fungal infections?
Pyrimidine analogs disrupt the synthesis of RNA and DNA.
44
Give an example of a pyrimidine analog used for treating fungal infections.
Flucytosine is a pyrimidine analog used to treat fungal infections.
45
Which drug class does Amphotericin B belong to, and why is it called "polyene antibiotics"?
Amphotericin B belongs to the polyene antibiotics drug class, named for the presence of conjugated double bonds in their structures.
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What is the spectrum of activity for Amphotericin B in terms of fungal infections?
Amphotericin B is active against a broad spectrum of pathogenic fungi.
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What are some common side effects or toxicities associated with Amphotericin B?
Common side effects of Amphotericin B include infusion reactions and renal damage.
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In which cases should Amphotericin B be used for treating fungal infections?
Amphotericin B should be employed only for infections that are progressive and potentially fatal and are unresponsive to other treatments.
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How many formulations of Amphotericin B are available, and what makes the lipid-based formulations different?
There are four formulations of Amphotericin B, with the lipid-based formulations being less toxic but more expensive.
50
What is the typical route of administration for all formulations of Amphotericin B, and how is it administered?
All formulations of Amphotericin B are administered by intravenous (IV) infusion.
51
What is the usual treatment regimen for Amphotericin B in the context of systemic mycoses?
Treatment with Amphotericin B typically involves daily or every other day infusions for several months.
52
How does Amphotericin B affect fungal cells at the membrane level?
Amphotericin B binds to components of the fungal cell membrane, increasing membrane permeability, which leads to the leakage of intracellular cations and reduced cell viability.
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Can Amphotericin B have fungistatic or fungicidal effects, and what factors determine this?
Amphotericin B can have fungistatic or fungicidal effects, depending on its concentration and the susceptibility of the fungus being treated.
54
What component of the fungal membrane does Amphotericin B bind to, and why is this important for susceptibility?
Amphotericin B binds to ergosterol, a sterol in the fungal cell membrane. Fungal cells must contain sterols like ergosterol to be susceptible to Amphotericin B.
55
Why are bacterial cells unaffected by Amphotericin B?
Bacterial membranes lack sterols, such as ergosterol, making them unaffected by Amphotericin B.
56
What causes the toxicity of Amphotericin B in mammalian cells, and why does some selectivity exist?
The toxicity of Amphotericin B in mammalian cells is primarily due to the presence of sterols, particularly cholesterol, in their membranes. There is some selectivity because Amphotericin B binds more strongly to ergosterol in fungal membranes than to cholesterol in mammalian membranes.
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Which microorganisms are susceptible to Amphotericin B?
Amphotericin B is effective against a broad spectrum of fungi and certain protozoa like Leishmania braziliensis.
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Are bacteria susceptible to Amphotericin B?
Bacteria are resistant to Amphotericin B.
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How often does the emergence of resistant fungi occur with Amphotericin B use, and what is associated with fungal resistance?
The emergence of resistant fungi due to Amphotericin B use is extremely rare and usually only happens with long-term usage. Fungal resistance is associated with reduced or absent amounts of ergosterol in their membranes, which is the drug's target.
60
What are the primary uses of Amphotericin B?
Amphotericin B is the drug of choice for most systemic mycoses (systemic fungal infections) and is also used for the treatment of leishmaniasis.
61
How did systemic fungal infections fare before the availability of Amphotericin B?
Systemic fungal infections were often fatal before the availability of Amphotericin B.
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What is the typical duration of treatment with Amphotericin B for systemic mycoses?
The treatment duration with Amphotericin B is usually prolonged, lasting 6 to 8 weeks, but in some cases may extend to several months.
63
Why can't Amphotericin B be administered orally for systemic infections?
Amphotericin B is poorly absorbed from the gastrointestinal (GI) tract, rendering oral therapy ineffective for systemic infections.
64
How is Amphotericin B typically administered for systemic infections?
Amphotericin B is administered intravenously for systemic infections.
65
What happens when Amphotericin B leaves the vascular system in the body?
After leaving the vascular system, Amphotericin B binds extensively to tissues containing sterols.
66
In which body fluids does Amphotericin B achieve approximately half the plasma levels?
Amphotericin B reaches about half the plasma levels in aqueous humor, peritoneal, pleural, and joint fluids.
67
What is the current understanding of amphotericin B's elimination from the body?
Little is known about the elimination of amphotericin B, and it is unclear whether the drug undergoes metabolism or is eventually removed from the body.
68
How is amphotericin B primarily eliminated from the body?
Renal excretion of unchanged amphotericin B is minimal.
69
When might dose or frequency reduction be considered for amphotericin B treatment?
Patients with preexisting renal impairment may require dose or frequency reduction during amphotericin B treatment.
70
How long does it take for complete elimination of amphotericin B from the body?
Complete elimination of amphotericin B is a slow process, with the drug detectable in tissues for more than a year after treatment cessation.
71
What are some of the serious adverse effects associated with amphotericin B?
Amphotericin B can cause a variety of serious adverse effects.
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In what setting should patients receiving amphotericin B be supervised?
Patients receiving amphotericin B should be closely supervised, preferably in a hospital.
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Why is amphotericin B used cautiously?
Amphotericin B is highly toxic.
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In what circumstances is amphotericin B typically prescribed?
Amphotericin B is primarily used in the setting of potentially life-threatening fungal infections due to its toxicity.
75
What adverse reactions are common during intravenous amphotericin B administration?
Fever, chills, rigors, nausea, and headache are common adverse reactions during intravenous amphotericin B administration.
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What causes these adverse reactions?
These reactions are caused by the release of proinflammatory cytokines from immune cells.
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When do the symptoms of these reactions typically start, and how long do they last?
Symptoms usually begin 1 to 3 hours after starting the infusion and last for about an hour.
78
How can mild reactions be managed?
Mild reactions can be managed with premedication like diphenhydramine and acetaminophen.
79
When might hydrocortisone be used, and why should its routine use be avoided?
Hydrocortisone may be used in cases where other measures fail to reduce fever and chills. Its routine use is discouraged because it can weaken the patient's ability to fight infections.
80
Are lipid-based amphotericin formulations associated with fewer infusion reactions?
Yes, lipid-based amphotericin formulations cause fewer and less intense infusion reactions than the conventional formulation.
81
How can the incidence of phlebitis during amphotericin infusion be minimized?
The incidence of phlebitis can be reduced by changing venous sites often, administering amphotericin through a large central vein, and using heparin as pretreatment.
82
Why does renal impairment occur in practically all patients receiving amphotericin B?
Renal impairment occurs because amphotericin B is toxic to kidney cells.
83
What factors determine the extent of kidney damage caused by amphotericin B?
The extent of kidney damage is related to the total dose of amphotericin B administered during the full course of treatment.
84
What typically happens to renal function after discontinuing amphotericin use?
In most cases, renal function normalizes after discontinuing amphotericin use.
85
When is residual kidney impairment likely to occur, and how can it be minimized?
Residual kidney impairment is likely if the total amphotericin dose exceeds 4 grams. Kidney damage can be minimized by infusing 1 liter of saline on amphotericin administration days and avoiding other nephrotoxic drugs.
86
How often should tests of kidney function be performed during amphotericin treatment, and what parameters should be monitored?
Kidney function tests should be performed every 3 to 4 days. Parameters to monitor include plasma creatinine content and fluid intake and output.
87
At what plasma creatinine content should amphotericin dosage be reduced?
Amphotericin dosage should be reduced if plasma creatinine content rises above 3.5 mg/dL.
88
Is the degree of renal damage different between lipid-based amphotericin formulations and the conventional formulation?
Yes, the degree of renal damage is less with lipid-based amphotericin formulations compared to the conventional formulation.
89
What is the potential bone marrow-related adverse effect of amphotericin B?
Amphotericin B can cause bone marrow suppression.
90
What type of anemia can result from bone marrow suppression due to amphotericin B?
Bone marrow suppression from amphotericin B can result in normocytic, normochromic anemia.
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How should the status of red blood cells be monitored during amphotericin B treatment?
Hematocrit determinations should be conducted to monitor the red blood cell status.
92
What happens when amphotericin is used with other nephrotoxic drugs like aminoglycosides, cyclosporine, or NSAIDs?
The risk of kidney damage increases.
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What is the recommended course of action when considering combinations of amphotericin with nephrotoxic drugs?
It is advisable to avoid such combinations whenever possible to reduce the risk of kidney damage.
94
How do azoles compare to amphotericin B in treating systemic fungal infections?
Azoles serve as an alternative to amphotericin B with lower toxicity and oral administration.
95
What is a disadvantage of azoles in terms of drug interactions?
Azoles inhibit hepatic cytochrome P450 drug-metabolizing enzymes, potentially increasing the levels of other drugs.
96
Which azoles are indicated for systemic mycoses?
Itraconazole, ketoconazole, fluconazole, voriconazole, posaconazole, and isavuconazonium.
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What are the therapeutic uses of Itraconazole (Sporanox)?
Blastomycosis, histoplasmosis, paracoccidioidomycosis.
98
How is Itraconazole available for administration?
100-mg capsules and a 10-mg/mL solution.
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What is the usual adult dose for Itraconazole?
200 mg 1–2 times daily.
100
What is the main adverse effect associated with Itraconazole?
Cardiac suppression and liver injury.
101
For which conditions is Fluconazole (Diflucan) used?
Blastomycosis, candidiasis, histoplasmosis.
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How is Fluconazole (Diflucan) available for administration?
Tablets (50-, 100-, 150-, 200-mg), suspension (10-mg and 40-mg/mL), and a solution for IV injection.
103
What are the adverse effects of Fluconazole (Diflucan)?
Nausea, headache, and Stevens-Johnson syndrome.
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What is the main therapeutic use of Voriconazole (Vfend)?
Aspergillosis, candidiasis, histoplasmosis.
105
How is Voriconazole (Vfend) available for administration?
Tablets (50-, 200-mg), suspension (40-mg/mL), and a solution for IV injection.
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What are the primary adverse effects associated with Voriconazole (Vfend)?
Hepatotoxicity, visual disturbances, and hypersensitivity reactions.
107
What is the role of Ketoconazole in treating systemic mycoses?
Ketoconazole is used for histoplasmosis, blastomycosis, and coccidioidomycosis.
108
What is Itraconazole (Sporanox)?
Itraconazole is an azole antifungal drug.
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What role does Itraconazole play in treating systemic mycoses?
It serves as an alternative to amphotericin B for several systemic mycoses.
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What are the advantages of using Itraconazole?
It is safer than amphotericin B and can be administered orally.
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What are the principal adverse effects associated with Itraconazole?
Cardiosuppression and liver injury.
112
How can Itraconazole affect the levels of other drugs?
Like other azoles, itraconazole can inhibit drug-metabolizing enzymes, potentially raising the levels of other drugs.
113
What is Amphotericin B, and which class of antifungal drugs does it belong to?
Amphotericin B is a polyene macrolide, and it belongs to the polyene antibiotic class.
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How does Amphotericin B work to combat fungal infections?
It binds to ergosterol in fungal cell membranes, disrupting them and causing leakage of intracellular cations, which can be fungistatic or fungicidal.
115
What is Amphotericin B commonly used for in the context of fungal infections?
It is used for most systemic mycoses, but it's known for its high toxicity.
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What is Itraconazole, and what role does it play in treating systemic mycoses?
Itraconazole is an azole antifungal drug that serves as an alternative to amphotericin B for systemic mycoses.
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What are the advantages of using Itraconazole?
Itraconazole is safer than amphotericin B and can be administered orally.
118
What is the potential downside of using Itraconazole concerning other medications?
Like other azoles, itraconazole can inhibit drug-metabolizing enzymes, potentially affecting the levels of other drugs.
119
What is Caspofungin, and which class of antifungal drugs does it belong to?
Caspofungin is an echinocandin, belonging to the echinocandin class of antifungal drugs.
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How does Caspofungin work against fungal infections?
Caspofungin inhibits the synthesis of β-1,3-d-glucan in fungal cell walls.
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What are the typical uses of Caspofungin in the context of fungal infections?
It is used for conditions like aspergillosis, candidiasis, and histoplasmosis.
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How does Itraconazole affect the synthesis of ergosterol in fungal cells?
Itraconazole inhibits ergosterol synthesis, leading to increased membrane permeability and the leakage of cellular components.
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What is the primary mechanism by which Itraconazole suppresses ergosterol synthesis?
Itraconazole works by inhibiting fungal cytochrome P450-dependent enzymes, which are essential for ergosterol production.
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Which fungal infections is Itraconazole a preferred treatment for?
Itraconazole is the drug of choice for blastomycosis, histoplasmosis, paracoccidioidomycosis, and sporotrichosis.
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In what cases can Itraconazole be an alternative to amphotericin B for treatment?
Itraconazole can be an alternative to amphotericin B in cases of aspergillosis, candidiasis, and coccidioidomycosis.
126
Besides systemic mycoses, what other type of fungal infections can Itraconazole be used to manage?
Itraconazole can also be used for superficial mycoses.
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How is Itraconazole typically administered?
Itraconazole is usually administered orally, either in the form of capsules or suspension.
128
What effect does taking Itraconazole with food have on its absorption, and does this apply to both capsules and suspension?
Taking Itraconazole with food enhances the absorption of capsules but decreases the absorption of the suspension.
129
What is the impact of taking Itraconazole with cola?
Interestingly, taking Itraconazole with cola can enhance its absorption.
130
In which type of tissues is Itraconazole widely distributed?
Itraconazole is distributed widely in lipophilic tissues.
131
Does Itraconazole reach significant concentrations in aqueous fluids like saliva and cerebrospinal fluid?
No, the concentrations of Itraconazole in aqueous fluids are negligible.
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How is Itraconazole metabolized in the body?
Itraconazole undergoes extensive hepatic metabolism.
133
What happens to approximately 40% of each Itraconazole dose in the body?
About 40% of each Itraconazole dose is excreted in the urine as inactive metabolites.
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How is Itraconazole typically tolerated at usual doses?
Itraconazole is generally well-tolerated at standard doses.
135
What are the most common adverse reactions associated with Itraconazole?
The most common adverse reactions include gastrointestinal symptoms like nausea, vomiting, and diarrhea.
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Besides gastrointestinal symptoms, what are some other potential side effects of Itraconazole?
Other potential side effects may include rash, headache, abdominal pain, and edema.
137
Name two potentially serious effects that can be associated with Itraconazole.
Itraconazole may lead to cardiac suppression and liver injury, both of which can be serious.
138
What cardiac effect can Itraconazole have?
Itraconazole can cause a transient decrease in ventricular ejection fraction, affecting the heart's pumping ability.
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Is the cardiac effect of Itraconazole permanent?
No, the reduction in cardiac function is temporary, and it typically returns to normal within 12 hours after dosing.
140
Can Itraconazole be used in patients with heart failure to treat serious fungal infections?
Yes, it can be used in such patients, but it should be administered with careful monitoring.
141
What condition should be met for the use of Itraconazole in patients with heart failure?
Its use should be justified by a clear benefit-to-risk assessment, where the benefits of treating the fungal infection outweigh the potential cardiac risks.
142
What action should be taken if patients with heart failure experience worsening signs and symptoms of heart failure while taking Itraconazole?
If heart failure worsens, Itraconazole should be discontinued.
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Is Itraconazole recommended for treating superficial fungal infections in all patients?
No, Itraconazole should not be used for superficial fungal infections in patients with heart failure, a history of heart failure, or signs of ventricular dysfunction.
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What are some conditions or indications that would disqualify a patient from using Itraconazole for superficial fungal infections?
Patients with current heart failure, a history of heart failure, or any signs of ventricular dysfunction should avoid using Itraconazole for superficial fungal infections.
145
Has Itraconazole been associated with liver failure?
Yes, there have been rare cases of liver failure linked to Itraconazole use.
146
What should patients on Itraconazole be aware of regarding their liver health?
Patients should be informed about the signs of liver impairment while taking Itraconazole.
147
What action should patients take if they notice signs of liver problems while using Itraconazole?
They should seek medical attention immediately if they experience any signs of liver impairment.
148
How does Itraconazole interact with the cytochrome P450 system?
Itraconazole inhibits CYP3A4, an enzyme within the cytochrome P450 system.
149
What risk is associated with concurrent use of Itraconazole and certain drugs?
Concomitant use of Itraconazole with specific drugs can lead to potentially fatal ventricular dysrhythmias.
150
Which medications are of particular concern when combined with Itraconazole?
Cisapride, pimozide, dofetilide, and quinidine are of particular concern when taken with Itraconazole.
151
Why is the simultaneous use of Itraconazole and these specific drugs contraindicated?
It can result in elevated levels of these drugs, posing a risk of life-threatening ventricular dysrhythmias.
152
What should be monitored in patients taking cyclosporine or digoxin alongside Itraconazole?
Levels of these drugs should be monitored.
153
For patients using warfarin with Itraconazole, what should be monitored?
Prothrombin time should be monitored regularly.
154
In patients on sulfonylureas and Itraconazole, what needs to be monitored?
Blood glucose levels should be monitored.
155
How does gastric acidity reduction affect the absorption of oral itraconazole?
Drugs that decrease gastric acidity, such as antacids, H2 antagonists, and proton pump inhibitors, significantly reduce the absorption of oral itraconazole.
156
What is the recommended timing for administering oral itraconazole in relation to drugs that reduce gastric acidity?
To optimize itraconazole absorption, it should be given either 1 hour before or 2 hours after drugs that reduce gastric acidity.
157
Why is special consideration required for patients using proton pump inhibitors (PPIs) with itraconazole?
PPIs have a prolonged duration of action and may suppress stomach acid for an extended period, potentially affecting itraconazole absorption.
158
What is the therapeutic goal of antifungal medications discussed in this context?
The goal is to treat both systemic and superficial mycoses (fungal infections).
159
What baseline data should be collected before initiating antifungal treatment?
Baseline tests of liver function should be conducted.
160
Is routine monitoring recommended during antifungal therapy for the general population?
No specific monitoring is recommended for most patients.
161
For whom should antifungal drugs be administered with caution?
They should be used with great caution in patients with liver disease.
162
How can therapeutic effects of antifungal treatment be evaluated?
Monitor for signs of antifungal effectiveness, such as a reduction in fever, pain, or inflammation.
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What should patients be instructed to do to minimize adverse effects when taking these antifungal medications?
Patients should be told to promptly report any signs of liver dysfunction. They should also avoid using these drugs with medications metabolized by CYP3A4, such as warfarin, cyclosporine, digoxin, and quinidine.
164
What antifungal is commonly used to treat oral candidiasis in premature and full-term infants?
Nystatin is used for this purpose.
165
How is systemic candidiasis treated in newborn infants?
Fluconazole is safely used to treat systemic candidiasis in newborn infants.
166
Are antifungal agents generally safe for children and adolescents?
Yes, many antifungal agents are safe for children, but they are typically administered at lower doses. The side-effect profiles are similar to those in adults.
167
What considerations are important when administering antifungals to pregnant women?
Risks and benefits must be carefully considered when giving antifungal medications during pregnancy.
168
Are most antifungals considered safe for breastfeeding women?
Yes, most antifungals are considered safe at lower doses during breastfeeding. However, ketoconazole, which has a high risk of hepatotoxicity, should be avoided.
169
What care concerns are relevant for older adults when it comes to antifungal therapy?
Older adults are at higher risk of achlorhydria, which can affect the absorption of certain antifungal agents. Additionally, azole antifungals can increase the levels of common medications prescribed to older adults, such as warfarin, phenytoin, and oral hypoglycemic agents.
170
What distinguishes echinocandins from other antifungal drug classes like amphotericin B and azoles?
Echinocandins disrupt the fungal cell wall, whereas amphotericin B and azoles target the fungal cell membrane.
171
Can echinocandins be administered orally?
No, echinocandins are not suitable for oral dosing.
172
Which fungal species are mainly targeted by echinocandins?
Echinocandins have a narrow spectrum of activity, primarily effective against Aspergillus and Candida species.
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How many echinocandins are available for use, and are they therapeutically equivalent?
There are three echinocandins available: caspofungin, micafungin, and anidulafungin. When dosed appropriately, all three are considered therapeutically equivalent.
174
What are the therapeutic uses of Caspofungin (Cancidas)?
Caspofungin is used to treat Aspergillosis and Candida infections.
175
How is Caspofungin administered, and what is the usual adult dosing?
Caspofungin is administered via IV injection. The usual adult dosing is an initial 70 mg IV, followed by 50 mg daily.
176
What are the common adverse effects associated with Caspofungin?
Common adverse effects may include fever and phlebitis at the injection site.
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What infections are Micafungin (Mycamine) primarily used to treat, and how is it administered?
Micafungin is primarily used to treat Candida infections and is administered via IV injection.
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What is the usual adult dosing for Micafungin, and what are its common adverse effects?
The usual adult dosing for Micafungin is 100 mg IV daily. Common adverse effects include headache, nausea, vomiting, and phlebitis at the injection site.
179
What are the therapeutic uses of Anidulafungin (Eraxis), and how is it administered?
Anidulafungin is indicated for Candida infections and is administered as a solution for IV injection.
180
What is the usual adult dosing for Anidulafungin, and what adverse effects might occur?
The usual adult dosing for Anidulafungin is 100-200 mg IV daily. Adverse effects may include diarrhea, hypokalemia, and histamine-mediated infusion reactions.
181
How does Caspofungin (Cancidas) work as an antifungal medication?
Caspofungin works by inhibiting the biosynthesis of β-1,3-d-glucan, which is essential for the cell wall of certain fungi.
182
For what conditions is Caspofungin approved for intravenous (IV) therapy?
Caspofungin is approved for IV therapy in cases of invasive aspergillosis in patients unresponsive to or intolerant of traditional agents and for managing systemic Candida infections, including candidemia, Candida-related esophagitis, peritonitis, pleural space infections, and intraabdominal abscesses.
183
How does Caspofungin compare to amphotericin B in terms of tolerability and effectiveness?
Caspofungin is better tolerated and appears to be just as effective as amphotericin B in treating fungal infections.
184
Why is Caspofungin administered intravenously (IV)?
Caspofungin is not absorbed from the gastrointestinal (GI) tract, so it must be given intravenously.
185
What percentage of Caspofungin is protein-bound in the bloodstream?
97% of caspofungin is protein bound in the blood.
186
What is the half-life of Caspofungin in the blood?
The half-life of caspofungin in the blood is 9 to 11 hours.
187
How is caspofungin primarily cleared from the bloodstream?
The primary mechanism for clearing caspofungin from the bloodstream is redistribution to tissues, rather than metabolism or excretion.
188
How is Caspofungin ultimately eliminated from the body?
Over time, caspofungin undergoes gradual metabolism, followed by excretion in both the urine and feces.
189
What are the most common adverse effects of Caspofungin?
The most common adverse effects of caspofungin include fever and phlebitis (inflammation of the vein) at the injection site.
190
What are some less common side effects of Caspofungin?
Less common side effects may include headache, rash, nausea, and vomiting.
191
How can Caspofungin affect patients in a way that appears to be mediated by histamine release?
Caspofungin may cause effects such as rash, facial flushing, pruritus (itching), and a sense of warmth due to histamine release.
192
What is anaphylaxis, and how is it related to Caspofungin?
Anaphylaxis is a severe, potentially life-threatening allergic reaction. While rare, there has been one reported case of anaphylaxis associated with caspofungin.
193
How can drugs like efavirenz, nelfinavir, rifampin, carbamazepine, dexamethasone, and phenytoin affect the levels of caspofungin in the body?
These drugs are known inducers of cytochrome P450 enzymes and may decrease the levels of caspofungin. Patients taking these inducers may need to increase their caspofungin dosage.
194
What is tacrolimus, and how is it related to caspofungin?
Tacrolimus is an immunosuppressant. Caspofungin can decrease the levels of tacrolimus in the body. If both drugs are taken together, it's important to monitor tacrolimus levels and adjust the dosage as needed.
195
What happens when caspofungin is combined with cyclosporine?
Combining caspofungin with cyclosporine can increase the risk for liver injury, as indicated by a transient elevation in plasma levels of liver enzymes. Therefore, this combination is generally best avoided.
196
What is the primary therapeutic goal when using echinocandins?
The primary therapeutic goal is to treat infections caused by Aspergillus and Candida species.
197
What baseline data should be obtained before initiating treatment with echinocandins?
Baseline liver function tests are recommended to assess liver health.
198
Who are considered high-risk patients for echinocandin use?
Echinocandins should be avoided during pregnancy. Additionally, patients with underlying liver dysfunction should be closely monitored.
199
How should healthcare providers evaluate the therapeutic effects of echinocandin treatment?
Monitor for indications of antifungal effects, such as a reduction in fever, pain, or inflammation.
200
What adverse effect should patients be instructed to report, and what interaction should be considered when using caspofungin?
Patients should be instructed to report signs of liver dysfunction, and it should be noted that caspofungin can decrease levels of tacrolimus.
201
What is the drug class of flucytosine?
Flucytosine belongs to the class of pyrimidine analogs.
202
What are the primary therapeutic uses of flucytosine?
Flucytosine is employed for treating serious infections caused by susceptible strains of Candida and Cryptococcus neoformans.
203
How is flucytosine commonly administered in clinical practice?
Flucytosine is typically used in combination therapy with amphotericin B to enhance its efficacy and reduce the development of resistance.
204
When should healthcare providers exercise extreme caution when using flucytosine?
Extreme caution is necessary when administering flucytosine to patients with renal impairment and those with hematologic disorders due to the potential for toxicity.
205
How does flucytosine exert its antifungal effect?
Flucytosine is taken up by fungal cells and is converted to 5-fluorouracil (5-FU), which acts as a powerful antimetabolite disrupting fungal DNA and RNA synthesis.
206
Why is flucytosine relatively harmless to mammalian cells?
Flucytosine is relatively harmless to mammalian cells because they lack the enzyme cytosine deaminase, which is necessary for the conversion of flucytosine to 5-FU.
207
What is the primary target within fungal cells affected by flucytosine?
The primary target of flucytosine within fungal cells is the disruption of DNA and RNA synthesis, leading to antifungal effects.
208
What makes 5-FU a potent antimetabolite in fungal cells?
5-FU, which results from the conversion of flucytosine, acts as a potent antimetabolite by interfering with essential processes like DNA and RNA synthesis in fungal cells.
209
What is the antifungal spectrum of flucytosine?
Flucytosine has a narrow antifungal spectrum.
210
Against which fungal species is flucytosine most effective?
Flucytosine is most effective against Candida species and C. neoformans.
211
Are many other fungi susceptible to flucytosine?
No, many other fungi are resistant to flucytosine.
212
In which fungal infections is flucytosine indicated for use?
Flucytosine is indicated for candidiasis and cryptococcosis.
213
Why is combination therapy of flucytosine with amphotericin B used for certain serious infections?
Combination therapy with amphotericin B is employed for serious infections like cryptococcal meningitis and systemic candidiasis because it offers two advantages: (1) it enhances antifungal activity and (2) it reduces the emergence of resistant fungi.
214
Is flucytosine easily absorbed from the gastrointestinal (GI) tract?
Yes, flucytosine is readily absorbed from the GI tract.
215
How well is flucytosine distributed throughout the body?
It is well distributed throughout the body.
216
Does flucytosine have access to the central nervous system (CNS), and what are the levels like in the cerebrospinal fluid (CSF)?
Flucytosine can access the CNS, and its levels in the CSF are approximately 80% of those in plasma.
217
How is flucytosine primarily eliminated from the body?
Flucytosine is primarily eliminated by the kidneys, mainly as unchanged drug.
218
What is the approximate half-life of flucytosine in patients with normal renal function?
The half-life of flucytosine in patients with normal renal function is about 4 hours.
219
In patients with renal insufficiency, how does flucytosine's half-life change, and what does this necessitate?
In patients with renal insufficiency, flucytosine's half-life is greatly prolonged, necessitating dosage reduction.
220
What is the most serious complication of flucytosine treatment?
The most serious complication of flucytosine treatment is bone marrow suppression.
221
How does marrow suppression usually manifest during flucytosine treatment?
Marrow suppression typically manifests as reversible neutropenia or thrombocytopenia.
222
Is agranulocytosis associated with flucytosine common or rare, and can it be fatal?
Agranulocytosis associated with flucytosine is rare, but it can be fatal.
223
How often should platelet and leukocyte counts be determined during flucytosine treatment?
Platelet and leukocyte counts should be determined weekly during flucytosine treatment.
224
What is the threshold level of plasma flucytosine above which adverse hematologic effects are more likely?
Adverse hematologic effects are more likely when plasma levels of flucytosine exceed 100 mcg/mL.
225
How should the dosage of flucytosine be adjusted to minimize adverse effects?
The dosage should be adjusted to maintain plasma drug levels below 100 mcg/mL.
226
In which patient population should flucytosine be used with caution?
Flucytosine should be used with caution in patients with preexisting bone marrow suppression.
227
What type of liver dysfunction is frequently associated with flucytosine treatment?
Mild and reversible liver dysfunction is frequently associated with flucytosine treatment.
228
Is severe hepatic injury a common or rare side effect of flucytosine?
Severe hepatic injury is rare but can occur.
229
How should liver function be monitored during flucytosine treatment?
Liver function should be monitored by making weekly determinations of serum transaminase and alkaline phosphatase levels.
230
In which type of patients should flucytosine be used with extreme caution?
Patients with renal impairment should use flucytosine with extreme caution.
231
What are the advantages of combining flucytosine with amphotericin B in the treatment of fungal infections?
Combining flucytosine with amphotericin B enhances antifungal activity and reduces the emergence of resistant fungi.
232
Why is it important to monitor renal function and flucytosine levels when using amphotericin B and flucytosine together?
The combination of amphotericin B and flucytosine can be detrimental due to amphotericin B-induced kidney damage, which may suppress flucytosine excretion, leading to flucytosine toxicity.
233
What is the risk associated with the inhibition of hepatic drug-metabolizing enzymes by flucytosine?
Inhibition of hepatic drug-metabolizing enzymes by flucytosine can lead to increased levels of several other drugs, including cisapride, pimozide, dofetilide, and quinidine, which can cause potentially fatal dysrhythmias.
234
Which specific drugs should flucytosine not be combined with due to the risk of potentially fatal dysrhythmias?
Flucytosine should not be combined with cisapride, pimozide, dofetilide, and quinidine due to the risk of potentially fatal dysrhythmias.
235
What are the two groups of organisms that cause superficial mycoses?
Superficial mycoses are caused by (1) Candida species and (2) dermatophytes.
236
Where do Candida infections typically occur, and what areas of the body can be involved in chronic infections?
Candida infections usually occur in mucous membranes and moist skin. Chronic infections may involve the scalp, skin, and nails.
237
What is the usual anatomical confinement for dermatophytoses?
Dermatophytoses are generally confined to the skin, hair, and nails.
238
Which type of superficial infections, Candida or dermatophytes, is more common?
Superficial infections with dermatophytes are more common than superficial infections with Candida.
239
What are the two types of drugs used to treat superficial mycoses?
Superficial mycoses can be treated with topical and oral drugs.
240
Which type of infections are topical agents typically preferred for in the treatment of superficial mycoses?
Topical agents are generally preferred for mild to moderate infections.
241
Where can you find specific indications for the drugs used against superficial mycoses?
Specific indications for these drugs are listed in Table 79.5.
242
Are some of the drugs used to treat superficial mycoses also used for systemic mycoses?
Yes, some of these drugs are also used for systemic mycoses.
243
What are the different forms of antifungal drugs available for treating superficial mycoses?
Antifungal drugs for superficial mycoses come in various forms, including topical creams, powders, vaginal tablets, oral tablets, shampoos, and more.
244
What are some of the conditions these drugs are used to treat?
These drugs are used to treat conditions such as ringworm (dermatophytic infections), Candida infections, and onychomycosis (fungal nail infections).
245
What are some common drug classes for treating superficial mycoses?
Common drug classes include azoles, allylamines, and others.
246
What are dermatophytic infections commonly known as?
Dermatophytic infections are commonly referred to as ringworm.
247
How many principal dermatophytic infections are there, and how are they defined?
There are four principal dermatophytic infections, and each is defined by its location:
248
What is tinea pedis, and how common is it?
Tinea pedis is a common fungal infection that primarily affects the feet.
249
What is the recommended treatment for tinea pedis?
Tinea pedis generally responds well to topical therapy.
250
What advice should patients with tinea pedis be given to help manage the condition?
Patients should be advised to:
251
What is tinea corporis, and what are common treatments for it?
Tinea corporis is a fungal infection affecting the body, commonly known as ringworm.
252
How long should treatment for tinea corporis continue after symptoms have cleared?
Tinea corporis usually responds well to topical azole or allylamine treatments.
253
In cases of severe tinea corporis infection, what may be required for treatment?
Treatment should continue for at least 1 week after symptoms have cleared.
254
What is tinea cruris, and how does it respond to treatment?
**Tinea cruris** is a fungal infection affecting the groin, commonly known as **ringworm**. - It typically responds well to **topical therapy**.
255
How long should treatment for tinea cruris continue after symptom clearance?
- **Treatment should continue for at least 1 week after symptoms have cleared**.
256
What additional treatments may be required for severe cases of tinea cruris with inflammation?
In cases of severe inflammation, a **systemic antifungal drug**, such as **clotrimazole**, may be required. Additionally, topical or systemic glucocorticoids may be needed in severe cases.
257
Why is tinea capitis difficult to treat with topical drugs?
Tinea capitis (ringworm of the scalp) is difficult to treat with topical drugs.
258
What is the standard therapy for tinea capitis, and how long is it typically taken?
The standard therapy for tinea capitis is oral griseofulvin, and it's usually taken for 6 to 8 weeks.
259
What alternative treatment may be more effective for tinea capitis, and how long is the course?
Oral terbinafine may be more effective, requiring a shorter course of 2 to 4 weeks.
260
How common is vulvovaginal candidiasis in women?
Vulvovaginal candidiasis is very common, affecting 75% of women at least once in their life.
261
What are the two most common causative agents of vulvovaginal candidiasis?
The most common causative agent is Candida albicans, followed by Candida glabrata in patients with HIV/AIDS.
262
What factors predispose individuals to Candida infections?
Factors that predispose to Candida infection include pregnancy, obesity, diabetes, debilitation, HIV infection, and the use of certain drugs, including oral contraceptives, systemic glucocorticoids, anticancer agents, immunosuppressants, and systemic antibiotics.
263
What are the main treatment options for vulvovaginal candidiasis?
Treatment options include topical therapy (1 or 3 days) and oral fluconazole (150 mg).
264
What are the potential side effects of oral fluconazole for vulvovaginal candidiasis?
Oral fluconazole can cause side effects such as headache, rash, and gastrointestinal disturbances.
265
How can recurrent vulvovaginal candidiasis be managed effectively?
For women with recurrent vulvovaginal candidiasis, weekly prophylaxis with oral fluconazole is highly effective, but relapse is common when treatment is stopped.
266
How is the choice of drug for treating vulvovaginal candidiasis typically determined?
The choice of drug is often based on patient preference, as all available options appear equally effective, and longer regimens do not offer a clear advantage.
267
What is another name for oral candidiasis?
Oral candidiasis is also known as thrush.
268
Is oral candidiasis a common condition?
Yes, oral candidiasis is a common condition.
269
What are some of the topical agents used to treat oral candidiasis?
Nystatin, clotrimazole, and miconazole are often effective topical agents for treating oral candidiasis.
270
When is oral therapy with fluconazole or ketoconazole usually required for treating oral candidiasis?
In immunocompromised individuals, oral therapy with fluconazole or ketoconazole is typically required to treat oral candidiasis.
271
Is onychomycosis easy to treat, and what type of treatment does it require?
Onychomycosis is difficult to eradicate and usually requires prolonged treatment.
272
What can cause onychomycosis?
Onychomycosis can be caused by dermatophytes or Candida species.
273
Why is treatment for onychomycosis often considered optional?
Treatment for onychomycosis is usually optional because it's largely a cosmetic concern.
274
What are the treatment options for onychomycosis?
Oral antifungal drugs and topical ciclopirox are among the treatment options for onychomycosis.
275
How effective are the treatments for onychomycosis?
The success rates with oral therapy are low, and the rates with topical therapy are even lower.
276
What are the common drugs used for the treatment of onychomycosis?
Terbinafine (Lamisil) and itraconazole (Sporanox) are commonly used.
277
What types of fungal infections are these drugs effective against?
These drugs are effective against Candida species and dermatophytes.
278
How do these drugs work within the body when treating onychomycosis?
These drugs become incorporated into keratin as the nails grow and may also diffuse into the nails from the tissue below.
279
What are some common side effects associated with these drugs?
Common side effects include headache, GI disturbances (nausea, vomiting, abdominal pain), and skin reactions (itching, rash).
280
What is the typical duration of treatment for onychomycosis with these drugs?
Treatment typically lasts 3 to 6 months.
281
What is the cure rate for onychomycosis with prolonged therapy using these drugs?
Unfortunately, the cure rate is relatively low, approximately 50%.
282
What is Ciclopirox used for in the context of onychomycosis?
Ciclopirox is a topical agent for onychomycosis.
283
What is the spectrum of activity for Ciclopirox in treating onychomycosis?
Ciclopirox is active against Trichophyton rubrum, a specific dermatophyte, and has no activity against Candida.
284
How is Ciclopirox applied for onychomycosis?
It is applied once a day to the nails and adjacent skin, with new coats applied over old ones. Once a week, all coats are removed with alcohol.
285
What are the typical side effects associated with Ciclopirox?
Side effects are minimal and localized.
286
What is the effectiveness of Ciclopirox in treating onychomycosis with prolonged use?
Prolonged use of Ciclopirox confers modest benefits, with complete cure occurring in less than 12% of patients, and a high recurrence rate (about 40%) even when complete cure occurs.
287
How does the safety and cost of topical Ciclopirox compare to oral therapy for onychomycosis?
Compared with oral therapy, topical Ciclopirox is safer and cheaper but is much less effective.
288
What is the medication Tavaborole (Kerydin) used for in the context of onychomycosis?
Tavaborole is used to treat onychomycosis caused by the dermatophytes Trichophyton rubrum and Trichophyton mentagrophytes.
289
What is the proposed mechanism of action for oxaborole antifungal medications like Tavaborole?
Oxaborole antifungals are thought to work by decreasing fungal protein synthesis.
290
In what form is Tavaborole available for use?
Tavaborole is available in a 5% solution for topical application.
291
How often should patients apply Tavaborole for onychomycosis treatment?
Patients should apply tavaborole to the entire nail surface and under the tip of affected toenails once daily.
292
What is the recommended treatment duration for Tavaborole in the management of onychomycosis?
The recommended treatment duration is 48 weeks.
293
What is the medication Efinaconazole (Jublia) used for?
Efinaconazole is used for the treatment of onychomycosis (fungal nail infection).
294
What is the formulation of Efinaconazole?
Efinaconazole is available as a 10% gel.
295
How should patients apply Efinaconazole to their affected toenails?
Patients should cover the entire nail, including the folds, bed, and undersurface of the toenail plate, using the brush applicator provided with the medication.
296
What is the recommended dosing schedule for Efinaconazole in the treatment of onychomycosis?
Patients should apply Efinaconazole once daily to the affected nails.
297
What is the duration of treatment with Efinaconazole for onychomycosis?
The recommended treatment period is 48 weeks.
298
How many members are there in the azole family of antifungal medications used for superficial mycoses?
There are twelve members in the azole family.
299
What is the usual route of administration for azole antifungals in the treatment of superficial mycoses?
The typical route is topical, where the medication is applied to the skin or affected areas.
300
Which types of pathogenic fungi are azoles generally effective against?
Azoles are effective against a wide range of pathogenic fungi, including dermatophytes and Candida species.
301
What is the mechanism of action of azoles in combating fungal infections?
Azoles work by inhibiting the biosynthesis of ergosterol, a critical component of the fungal cytoplasmic membrane.
302
Name three azoles that are also used for systemic mycoses in addition to superficial mycoses.
Three azoles used for both systemic and superficial mycoses are itraconazole, fluconazole, and ketoconazole.
303
How is griseofulvin typically administered for the treatment of fungal infections?
Griseofulvin is administered orally.
304
Which type of fungal infections is griseofulvin primarily used to treat?
Griseofulvin is used to treat superficial mycoses, which are fungal infections of the skin, hair, and nails.
305
Is griseofulvin effective against organisms that cause systemic mycoses?
No, griseofulvin is inactive against the organisms that cause systemic mycoses, which are fungal infections affecting internal organs or the entire body.
306
How does griseofulvin work in preventing fungal infections in the skin, hair, and nails?
Griseofulvin is deposited in keratin precursor cells after absorption, making newly formed keratin resistant to fungal invasion.
307
By what mechanism does griseofulvin kill fungi?
Griseofulvin kills fungi by inhibiting fungal mitosis, primarily by binding to components of microtubules that form the mitotic spindle.
308
Does griseofulvin affect all fungi equally?
No, griseofulvin primarily affects actively growing fungi because it disrupts the mitotic process.
309
What is the usual route of administration for griseofulvin?
Oral administration.
310
How can the absorption of griseofulvin be enhanced?
Absorption can be enhanced by taking it with a fatty meal.
311
Where is griseofulvin deposited in the body after absorption, and how does this help prevent fungal infections?
Griseofulvin is deposited in the keratin precursor cells of skin, hair, and nails, making newly formed keratin resistant to fungal invasion.
312
What are the primary routes of elimination for griseofulvin?
Griseofulvin is metabolized in the liver and eliminated through renal excretion.
313
How is griseofulvin administered for the treatment of dermatophytic infections?
Griseofulvin is administered orally.
314
Is griseofulvin effective against Candida species or systemic mycoses?
No, it is not effective against Candida species or systemic mycoses.
315
What is the typical response time for treating dermatophytic infections of the skin with griseofulvin?
Dermatophytic infections of the skin typically respond relatively quickly, within 3 to 8 weeks.
316
How long might it take to eliminate infections of the toenails with griseofulvin treatment?
Eliminating infections of the toenails may require a year or more of treatment.
317
What is nystatin primarily used for in the treatment of fungal infections?
Nystatin is primarily used for treating candidiasis.
318
What is the drug of choice for treating intestinal candidiasis?
Nystatin is the drug of choice for intestinal candidiasis.
319
Where can candidal infections be treated with nystatin?
Candidal infections of the skin, mouth, esophagus, and vagina can be treated with nystatin.
320
Can nystatin be administered orally and topically?
Yes, nystatin can be administered both orally and topically.
321
What are the potential adverse effects of oral nystatin?
Oral nystatin may occasionally cause GI disturbance, including nausea, vomiting, and diarrhea.
322
What kind of adverse effects may be associated with topical application of nystatin?
Topical application of nystatin may produce local irritation.
323
What is naftifine, and under what brand name is it sold?
Naftifine is a topical antifungal medication sold under the brand name Naftin.
324
What are the primary indications for using naftifine?
Naftifine is used for the treatment of dermatophytic infections, which are fungal infections of the skin.
325
How does naftifine work to combat fungal infections?
Naftifine inhibits squalene epoxidase, hindering the synthesis of ergosterol, a key component of the fungal cell membrane.
326
What are the most common adverse effects associated with naftifine?
The most common adverse effects are burning and stinging at the application site.
327
How well is naftifine absorbed after topical administration?
Naftifine is poorly absorbed after topical administration, with a low absorption rate of about 6%.
328
Have any significant systemic effects been reported with the use of naftifine?
No, significant systemic effects have not been reported with naftifine use.
329
In what formulations is naftifine available, and how often is each typically applied?
Naftifine is available in two formulations: 1% and 2% cream and 1% gel. The cream is applied once daily, while the gel is applied twice daily.
330
How long is the typical duration of naftifine treatment?
Treatment with naftifine often lasts 2 to 4 weeks.
331
What are the primary uses of butenafine, and in which topical products can it be found?
Butenafine is a topical antifungal used for the treatment of fungal infections, and it is available in products like Lotrimin Ultra Cream and Mentax.
332
How does butenafine compare to other antifungal medications like naftifine and terbinafine?
Butenafine is chemically similar to naftifine and terbinafine, although it does not belong to the true allylamine class.
333
What is the mechanism of action of butenafine in treating fungal infections?
Like other similar antifungal agents, butenafine inhibits squalene epoxidase, leading to the inhibition of ergosterol synthesis in fungal cells.
334
For which fungal infections is butenafine indicated for topical therapy?
Butenafine is indicated for the topical therapy of fungal infections, including tinea pedis, tinea corporis, tinea cruris, and tinea versicolor.
335
How well is butenafine absorbed through the skin, and what is the likelihood of systemic side effects?
Absorption of butenafine is minimal, and systemic side effects are not typically reported.
336
What are some common local reactions that may occur with the use of butenafine?
Common local reactions can include burning, stinging, erythema (redness), irritation, and itching.
337
How often is the 1% cream formulation of butenafine applied, and what is the typical treatment duration?
The 1% cream formulation of butenafine is applied once daily, and treatment usually lasts 2 to 4 weeks.
338
What is the primary use of tolnaftate, and in which topical products can it be found?
Tolnaftate is a topical antifungal medication used to treat various superficial mycoses and can be found in products like Tinactin.
339
Against which fungal organisms is tolnaftate effective, and what type of fungi does it not work against?
Tolnaftate is effective against dermatophytes, but it does not work against Candida species.
340
What is currently known about the mechanism of action of tolnaftate as an antifungal agent?
The exact mechanism of antifungal action of tolnaftate is unknown.
341
How common are adverse effects associated with tolnaftate, and what are some examples of these effects?
Adverse effects, such as sensitization and irritation, are extremely rare.
342
In what formulations is tolnaftate available, and which are considered the most effective?
Tolnaftate is available in several formulations, with creams, powders, and solutions being the most effective. Powders are used adjunctively.
343
How frequently should tolnaftate be applied, and what is the typical treatment duration?
The drug is applied twice daily and is typically used for a duration of 2 to 4 weeks.
344
What is the primary use of undecylenic acid, and in which topical products can it be found?
Undecylenic acid is a topical antifungal agent used to treat superficial mycoses and can be found in products like Fungi-Nail.
345
Against which fungal organisms is undecylenic acid effective, and what type of fungi does it not work against?
Undecylenic acid is effective against dermatophytes but does not work against Candida species.
346
What is the major indication for undecylenic acid use?
The major indication for undecylenic acid is tinea pedis (athlete's foot).
347
While undecylenic acid is used for treating tinea pedis, which antifungal drugs are generally considered more effective for this purpose?
Other antifungal drugs, such as tolnaftate and the azoles, are generally considered more effective for treating tinea pedis.
348
What is ciclopirox, and what is its primary use?
Ciclopirox is a topical antifungal agent used to treat fungal infections of the skin.
349
Against which types of fungi is ciclopirox active when applied to the skin?
Ciclopirox is active against dermatophytes and Candida species when applied to the skin.
350
What are the common indications for using ciclopirox to treat skin infections?
Ciclopirox is effective in treating various superficial fungal infections, including superficial candidiasis, tinea pedis (athlete's foot), tinea cruris, and tinea corporis.
351
How does ciclopirox behave in terms of absorption and toxicity when applied topically?
When applied topically, ciclopirox penetrates into the skin layers, but systemic absorption is minimal, and it does not lead to significant systemic accumulation. Local application does not result in toxicity.
352
What are the available formulations of ciclopirox for treating skin infections, and how should they be used?
For skin infections, ciclopirox is available as a 1% shampoo and as a 0.77% cream, gel, and suspension. The shampoo is typically used twice weekly for 4 weeks, while the cream, gel, and suspension are applied twice daily for 2 to 4 weeks.
