Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
32 Cards in this Set
- Front
- Back
Names of polyenes antifungals |
Amphotericin B Nystatin |
|
Mechanism of action of anti fungal agents? |
Inhibit ergosterol (replaces cholesterol functions) synthesis. |
|
Special pharmacokinetics of amphotericin B? |
Binds strongly to tissues - long plasma half-life of 15 days. Hence not good use systemically |
|
Mode of administration of amphotericin B? |
Oral and IV |
|
MOA of nystatin? |
Pessary |
|
Spectrum of activity of Amphotericin B? |
Gold standard for all anti fungal agents - Broad |
|
Uses of Polyenes? |
Amphotericn B - Invasive aspergillosis, histoplasmosis, Systemic candidiasis (ABC) Nystatin - Vaginal Candidiasis |
|
Adverse effects of Amphotericin B? |
- Infusion reaction ("shake and bake" syndrome) Precaution - use a small test dose, slow infusion of final dose over 2-4hrs - Thrombophlebitis - Nephrotoxicity |
|
Name 2 azoles |
Imidazoles - Clotrimazole, Miconazole (ICM) Triazoles - Itraco, fluco, vorico-nazoles |
|
How are azoles administered? |
Imidazoles- Topical preparations (cream, lotion, powder, pessary) Triazoles - Oral |
|
Which drug is a useful alternative to amphotericin B for treating systemic fungal infections? |
Imidazoles |
|
Adverse effects of imidazole and triazoles? |
Imidazoles: Mild side effects Triazoles - cause GIT disturbance and mild rash, S-J syndrome occasionally occurs. |
|
Voriconazole is contraindicated with what? |
Foetal toxicity - avoid use in pregnancy |
|
Flucytosine mechanism of action? |
Disrupt synthesis of fungal RNA and dna |
|
Echinocandin example? |
Caspofungin |
|
Mechanism of caspofungin? |
Inhibit synthesis of gluten -> disrupt fungal cell wall and causes cell death |
|
How to administer echinocandins? |
Parenteral (IV) |
|
Spectrum of activity for flucytosine and caspofungin? |
Both Narrow.
|
|
When do you use echinocandins (caspofungin?) |
Salvage therapy in patients with invasive aspergillosis (failed response to amphotericin B) |
|
When do you use Flucytosine? |
During systemic yeast infections (Systemic Candidiasis and Cryptococcal meningitis) and give orally. Combine with Amphotericin B. |
|
How to administer flucytosine? |
Orally. |
|
Adverse effects of flucytosine? |
1. Bone marrow suppression 2. Hepatotoxicity |
|
Drugs to take note when using caspofungin? |
CYP450 inducers like rifampicin, carbamazepine can reduce plasma levels of caspofungin, hence requiring higher dose. |
|
What to note when taking terbinafine (topical)? |
Can cause dry skin. These can be avoided by not using >4 weeks. |
|
What subgroup is flucystine under? |
Pyramidine analogues. |
|
Name an antiprotozoal agent? |
Metronidazole |
|
Mechanism of action of metronidazole? |
Interferes with nucleic acid synthesis |
|
Mode of administration of metronidazole? |
Orally (rapid and complete absorption) |
|
Distribution of metronidazole? |
Distribution: penetrates well into body tissues and fluids, breast milk, saliva, CSF, vaginal and seminal fluids. |
|
Spectrum of activity for metronidazole? |
Protozoans and anaerobic bacteria (eg. Clostridium difficile) |
|
Adverse effects of metronidazole? |
1. MOST COMMON - bitter metallic taste, dry mouth, N/V
2. COMMON - GIT-related, diarrhoea, vomiting. CNS-related: insomnia, vertigo
|
|
Precautions while taking metronidazole? |
Avoid in pregnant patients. |