Infection: Antifungals, systemic use Flashcards Preview

BNF/Pre-Reg 2017-2018 > Infection: Antifungals, systemic use > Flashcards

Flashcards in Infection: Antifungals, systemic use Deck (38)
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1
Q

Aspergillosis most commonly affects what? What is the exception?

A

Most commonly affects the respiratory tract but in severly immunocompromised patients, invasive forms can affect the heart, brain, and skin.

2
Q

What is the treatment of choice for aspergillosis?

A

Voriconazole, however liposomal amphotericin is an alternative first-line treatment when voriconazole cannot be used.

3
Q

What is the second line treatment of aspergillosis if voriconazole cannot be used?

A

Liposomal amphotericin.
Caspofungin or itraconazole, can be used in patients who are refractory to, or intolerant of voriconazole and liposomal amphotericin.

4
Q

What are the third line treatment options for aspergilosis if voriconazole + liposomal amphotericin are contra-indicated?

A

Caspofungin or itranconazole.

5
Q

Posaconazole is licensed for use in aspergillosis in what circumstances?

A

INVASIVE aspergillosis and intolerance of itraconazole and amphotericin.

6
Q

Vaginal candidiasis unresponsive to oral fluconazole can be treated with:

A

Itraconazole oral.

7
Q

For invasive or disseminated candidiasis, what is used?

A

An echinocandin.

8
Q

What is the most common form of fungal menigitis?

What patient groups is it seen in typically?

A

Cryptococcosis is uncommon but infection in the immunocompromised, especially in HIV-positive patients, can be life-threatening; cryptococcal meningitis.

9
Q

What is the treatment of choice in cryptococcal meningitis?

A

Amphotericin by intravenous infusion and flucytosine by intravenous infusion for 2 weeks, followed by fluconazole by mouth for 8 weeks or until cultures are negative.

10
Q

Histoplasmosis is rare in temperate climates; it can be life-threatening, particularly in HIV-infected persons. What is the treatment of choice of immunocompetent patients with indolent non-meningeal infection, including chronic pulmonary histoplasmosis?

A

Itraconazole.

11
Q

When is amphotericin used in the treatment of histoplasmosis considering itraconazole is first-line?

A

Amphotericin by intravenous infusion is used for the initial treatment of fulminant or severe infections, followed by a course of itraconazole by mouth. Following successful treatment, itraconazole can be used for prophylaxis against relapse until immunity recovers.

12
Q

In the treatment of skin and nail fungal infections, why are oral imidazole or triazole antifungals (itraconazole) and terbinagine used more frequently than griseofulvin?

A

They have a broader spectrum of activity and require a shorter duration of treatment.

13
Q

What is tinea capitis?

A

Ringworm of scalp, needs systemic treatment although topical application of an antifungal may reduce transmission. Griseofulvin is used in adults and children.

14
Q

Amphotericin by intravenous infusion and flucytosine by intravenous infusion for 2 weeks, followed by fluconazole by mouth for 8 weeks or until cultures are negative. Treatment of choice for:

A

Cryotoccal meningitis

15
Q

How is tinea capitis treated?

A

Griseofulvin

16
Q

What is pityriasis versicolor?

A

Also known as tinea versicolor, a common condition that causes small patches of skin to become scaly and discoloured.

Occurs a lot in moist, warm places.
Caused by a yeast called Malassezia.

ketocoazole shampoo

17
Q

How is pityriasis versicolor treated?

A

Itraconazole by mouth or fluconazole by mouth.

ketoconazole shampoo

Oral terbinafine is not effective for pityriasis versicolor.

18
Q

Immunocompromised patients are at particular risk of fungal infections and may receive antifungal drugs prophylactically. What are the drugs of choice?

A

Oral triazole antifungals:
Fluconazole is more reliably absorbed than itraconazole, but fluconazole is not effective against Aspergillus spp. so itraconazole is preferred in patients at risk of aspergillosis.

19
Q

Why is itraconazole preferred over fluconazole in the prophylaxis of aspergillus infections of the immunocompromised?

A

Fluconazole is not active against Aspergillus spp.

20
Q

What are the four main classes of antifungals (and examples)?

A
  1. Triazole antifungals: fluconazole, itraconazole, posaconazole, voriconazole.
  2. Imidazole antifungals: clotrimazole, econazole nitrate, ketoconazole and tioconazole, miconazole.
  3. Polyene antifungals: amphotericin and nystatin.
  4. Echinocandin: anidulafungin, caspofungin and micafungin.
21
Q

What are the triazole antifungals?

A

Fluconazole
Itraconazole
Posaconazole
Voriconazole

22
Q

What are the imidazole antifungals?

A

Clotrimazole
Econazole
Ketoconazole
Miconazole

23
Q

What are the polyene antifungals?

A

Amphotericin
Nystatin
Neither systemically available via mouth

24
Q

What are the echinocandin antifungals?

A

Anidulafungin
Caspofungin
Micafungin

25
Q

Other than the four main classess of antifungal agent (triazole, imidazole, polyene and echinocandin) what others exist? (3)

A

Flucytosine
Griseofulvin
Terbinafine

26
Q

What does fluconazoles absorption and excretion characteristics mean for its clinical uses?

A

Fluconazole is very well absorbed after oral administration. It also achieves good penetration into the cerebrospinal fluid to treat fungal meningitis. Fluconazole is excreted largely unchanged in the urine and can be used to treat candiduria.

27
Q

Which triazole antifungal is cautioned in people with liver disease?

A

Itraconazole has been associated with liver damage and should be avoided or used with caution in patients with liver disease; fluconazole is less frequently associated with hepatotoxicity.

28
Q

Which triazole antifungal requires an acid environment in the stomach for optimal absorption?

A

Itraconazole capsules require an acid environment in the stomach for optimal absorption.

29
Q

Clotrimazole is mostly only effective against

A

Candida albicans

30
Q

What imidazole antifungal can be used for oral thrush?

A

Miconazole, daktarin oral gel.

31
Q

What are the uses of the polyene antifungal nystatin?

A

Oral, oropharyngeal, and perioral infections by local application in the mouth.

Nystatin is also used for Candida albicans infection of the skin.

32
Q

Why do lipid formulations of amphotericin (polyene antifungal) exist?

A

When given parenterally amphotericin is toxic and side-effects are common. Lipid formulations of amphotericin (Abelcet® and AmBisome®) are significantly less toxic and are recommended when the conventional formulation of amphotericin is contra-indicated because of toxicity, especially nephrotoxicity or when response to conventional amphotericin is inadequate; lipid formulations are more expensive.

33
Q

The echinocandin antifungals anidulafungin, caspofungin and micafungin are only active against what?

A

Aspergillus spp. and Candida spp.

However, anidalufungin and micafungin are NOT used for asperfillosis.

34
Q

What is the role in therapy of fluctyosine?

A

Flucytosine is used with amphotericin in a synergistic combination. Bone marrow depression can occur which limits its use, particularly in HIV-positive patients; weekly blood counts are necessary during prolonged therapy. Resistance to flucytosine can develop during therapy and sensitivity testing is essential before and during treatment. Flucytosine has a role in the treatment of systemic candidiasis and cryptococcal meningitis.

35
Q

What are the issues with using flucytosine and amphotericin together?

A

Flucytosine is used with amphotericin in a synergistic combination. Bone marrow depression can occur which limits its use, particularly in HIV-positive patients; weekly blood counts are necessary during prolonged therapy. Resistance to flucytosine can develop during therapy and sensitivity testing is essential before and during treatment. Flucytosine has a role in the treatment of systemic candidiasis and cryptococcal meningitis.

36
Q

When is griseofulvin used?

A

Not much anymore, it is effective for widespread or intractable dermatophyte infections but has been superseded by newer antifungals, particularly for nail infections.

37
Q

Terbinafine is the drug of choice for what?

A

fungal nail infections and is also used for ringworm infections where oral treatment is considered appropriate.

38
Q

What monitoring should accompany the use of oral terbinafine?

A

Hepatic function before treatment and then periodically after 4-6 weeks.

Discontinue if abnormalities develop.

Decks in BNF/Pre-Reg 2017-2018 Class (144):