Slide 7 Antifungal

Question 1

Amphotericin B

Answer 1

• Polyene
• Must give IV or intrathecal
• membranes & forms artificial “ pores”
• binds to ergosterol
• liposomal

Question 2

Amphotericin B D.O.C.

Answer 2

Aspergillus, cryptococcus

Question 3

Why does Amphotericin B cause nephrotoxicity?

Answer 3

Highly water soluble after first 24 hours, its a large molecule. Its main job is to create pores, so it creates pores in the lining of the nephron.

Question 4

Side affects of Amphotericin B?

Answer 4

Fever, nausea, vomiting, headache. Treat with antihistamines.

Question 5

Flucytosine mechanism?

Answer 5

Cytosine deaminase is converted to - 5FU - then FUTP decreases RNA, F-dUMP decreases DNA

Question 6

Flucytosine is given

Answer 6

orally, and distributed in CNS

Question 7

You should always give Flucytosine in combination with?

Answer 7

Amphotericin B

Question 8

-Azoles mechanism?

Answer 8

14 alpha demethylase - converts lanesterol to ergosterol.

IT is a CYP450 enzyme which can affect the hosts ability to make cholesterol and sex androgens.

Question 9

Voriconazole

Answer 9

invasive Aspergillosis,

Question 10

Fluconazole

Answer 10

• DOC or Co-DOC in most systemic fungal infection (less toxic than AMB)
• Good CSF delivery (prophylaxis & supression of cryptococcal meningitis)
  
  • more selective for fungal P450s

Question 11

Echinocandin drug name?

Answer 11

Caspofungin

Question 12

Caspofungin mechanism

Answer 12

inhibits b-glucan, glucan synthase.

Question 13

Caspofungin effects

Answer 13

Hypotension and tachycardia
Fever, chills and headache
Rash
Anemias
Hypokalemia

Question 14

Caspofungin use?

Answer 14

Treatment of invasive Aspergillus infections in patients who are refractory or intolerant of other therapy

Question 15

Nystatin

Answer 15

Similar to amphotericin B, too toxic for systemic use.Swish & swallow in oral candidiasis,topical for diaper rash or vaginal candidiasis.

Question 16

Griseofulvin

Answer 16

Active only against Dermatophytes (Administered orally), concentrates in newly formed keratinized tissue .
Act by disrupting microtubular structure
Potent CYP450 Inducer
-Disulfiram like effect

Question 17

Terbinafine

Answer 17

Inhibits squalene epoxidase (ergosterol synthesis)

Question 18

Metronidazole used for?

Answer 18

Protozoa

Question 19

Metronidazole clincial uses?

Answer 19

Protozoa:
Urogenital trichomoniasis (Trichomonas vaginalis)
Giardiasis (Giardia)
Amebiasis (Entamoeba histolytica)

Bacteria:

Question 20

Metronidazole clincial bacteria?

Answer 20

Bacteria:
Anaerobic bacterial infections below diaphragm (including Clostridium difficile, Bacteroides fragilis ,Gardinella vaginalis & Acne Rosacea).
H. Pylori {used with bismuth & amoxycillin (or tetracycline) as ‘triple therapy’}.

Question 21

Metronidazole affects?

Answer 21

Stomatitis, metallic taste, leukopenia, cystitis, Reversible peripheral neuropathy (free redical injury)

• disulfiram effect
• headache.