Antiparasitic/Antifungal Flashcards
1
Q
metronidazole (Flagyl)
A
- antiparasitic
- MOA: activated by pyruvate:ferrodoxin oxidoreductase (PFOR)–> bind and disrupt protein and DNA structure/function
- activated under anaerobic conditions
- use: trichomoniasis (partners treated simultaneously), giardiasis, amebiasis
- effective against trophozoite form NOT cyst form
- adverse effects: headache, dry mouth, metallic taste, vomiting, diarrhea, disulfiram-like effect (avoid alcohol
- safe during pregancy
- resistance: RARE, some decreased PFOR activity
2
Q
idoquinol
A
- antiparasitic
- MOA: unknown
- use: eliminate trophozoite AND cyst form of E.histolytica in lumen of intestines (poorly absorbed)
- used in combo with metronidazole
- adverse effects: GI discomfort (take w/ food), optic atrophy, permanent vision loss (long term use)
- resistance: no information
3
Q
paromomycin
A
- antiparasitic
- MOA: aminoglycoside antibiotic–>inhibit protein synthesis in bacteria
- use: eliminate trophozoite and cyst form of E. histolytica from lumen of intestine NOT tissue
- combo w/ metronidazole
- adverse effects: abdominal discomfort, less toxic than iodoquinol
- resistance: unknown
4
Q
nitazoxanide
A
- antiparasitic
- MOA: interference with PFOR–>disrupt anaerobic energy metabolism
- use: Cryptosporidium parvum, Giardia lamblia for >1yo
- resistance: unknown
5
Q
pyrimethamine-sulfadiazine
trimethoprim-sulfamethoxazole (TMP-SMX)
A
- antiparasitic
- MOA: sulfonamides–> inhibit production of pteroic acid from PABA by dihydropteroate synthase; diaminopyrimidines–>inhibit DHFR enzyme–> prevent tetrahydrofolate formation
- pyrimethamine-sulfadiazine: toxoplasmosis, ineffective against tissue cyst
- TMP-SMX: Pneumocystis jirovecii
- synergistic effect when in combo
- adverse effects: rash, GI intolerance
- can induce folate deficiency–> leucovorin co-administered
- resistance: aa substitutions in targeted enzymes
6
Q
chloroquine
A
- antimalarials
- MOA: interfere w/ parasite ability to detoxify compound from degradation of hemoglobin
- use: asexual erythrocytic stage of all Plasmodium, prophylaxis and clinical disease
- adverse effects: headache, nausea, vomiting, blurred vision, dizziness, fatigue, confusion
resistance: BIG TIME, rapid export, pump?
7
Q
quinine
A
- antimalarial
- MOA: digestive vacuoles–>interfere with hemoglobin degradation or detoxification of metabolic products; complex with DNA–>interfere w/ transcription and replication
- use: eliminate asexual erythrocytic stage of Plasmodium clinical disease, IV admin
- adverse effects: WORST, cinchonism, hypoglycemia
- resistance: beginning in Asia
8
Q
mefloquine
A
- antimalarial
- MOA: similar to quinine?
- use: intraerythromcytic form of Plasmodium, prophylaxis and treatment
- adverse effects: some neuropsychiatric reactions
- resistance: none
9
Q
primaquine
A
- antimalarial
- MOA: activation by host–> interfere w/ mitochondrial ETC and pyrimidine synthesis
- use: dormant liver (hypnozoite) form of P. vivax and P. ovale
- adverse effects: hemolysis in G6PD pts
- resistance: some
10
Q
malarone
A
- antimalarial
- atovaquone: MOA unknown
- proguanil: MOA–>inhibits DHFR–> inhibit folate synthesis
- use: treament of P. falciparum, prophylaxis
- resistance: none reported
11
Q
doxycylcine
A
- antimalarial, tetracycline antibiotic
- MOA: inhibit protein synthesis
- use: prophylaxis or treatment in combo
- adverse effects: photosensitivity dermatitis, staining of teeth in children (contraindicated in children and pregnancy)
- resistance: little evidence
12
Q
artemisinin
A
- antimalarial, extracted from Chinese wormwood
- MOA: interact with iron–> radicals damage membranes?
- use: all Plasmodium
- adverse effects: minor nausea and diarrhea
- resistance: declining susceptibility
13
Q
albendazole
A
- anthelminitic-benzimidazole
- MOA: inhibit mitosis, cause muscle paralysis of parasite
- poorly soluble
- empty stomach for luminal nematodes, fatty meal for tissue dwelling
- use: acariasis, pinworms, hookworm, whipworm
- adverse effects: primarily GI
- contraindicated in pregnancy and possible
14
Q
mebendazole
A
- anthelminitic-benzimidazole
- MOA: inhibit mitosis, cause muscle paralysis of parasite
- poorly soluble
- empty stomach for luminal nematodes, fatty meal for tissue dwelling
- use: acariasis, pinworms, hookworm, whipworm
- adverse effects: primarily GI
- contraindicated in pregnancy and possible
15
Q
thiabendazole
A
- anthelminitic-benzimidazole
- MOA: inhibit mitosis, cause muscle paralysis of parasite
- absorbed–>greater toxicity
- empty stomach for luminal nematodes, fatty meal for tissue dwelling
- use: 2nd line strongyloidiasis, cutaneous larval migrans
- adverse effects: anorexia, nausea, vomiting, delirium, hallucinations
- contraindicated in pregnancy and possible
16
Q
ivermectin
A
- anthelmintics
- MOA: increase Cl- permeability–> hyperpolarization–> muscle paralysis
- use: strongyloidiasis (intestinal and extraintestinal), tissue dwelling nematodes
- resistance: none
17
Q
pyrantel pamoate
A
- anthelminitic
- MOA: activate cholinergic nicotinic receptors in somatic muscles–>depolarizing neuromuscular blockade
- poorly absorbed–>luminal nematodes
- use: pinworms, treat ENTIRE family, secondary drug for Ascaris and hookworm
- resistance: none
18
Q
praziquantel
A
- Against cestodes (tapeworms) and trematodes (flukes)
- MOA: increase Ca2+ permeability–> depolarization; increased immune detection; induce spastic paralysis in trematodes
- adverse effects: immune response to dying worm (fever, rash, myalgia), headache, abdominal discomfort
- use: flukes, tapeworms, cysticerosis
resistance: some Schistosomes
19
Q
amphotericin B
A
- systemically active drugs for systemic infections
- polyenes
- MOA: bind ergosterol in cell membrane–> forms pore–> fungicidal
- use: systemic yeast (Candida, Cryptococcus), systemic molds (Aspergillus, Histoplasma, Coccidioides, Blastomyces, Sporothrix, mucormycoses)
- resistance: decrease ergosterol, seen in Candida and Aspergillus
- does NOT penetrate CNS
- adverse effects: fever, chills, hypertension, vomiting, nephrotoxicity (decreased renal perfusion)
- liposomal packaged–>less toxic
20
Q
ketoconazole
miconazole
clotrimazole
A
- azole, imidazole
- MOA: bind enzyme responsible for converting lanosterol to ergosterol–> leaky cell membrane
- use: pathogenic yeast, systemic mycoses, dermatophytes
- systemic activity (ketoconazole), topical use for others
- adverse effect: inhibits liver cytochrome P450 enzymes
- less selective toward fungi–> not used as often
- resistance: efflux pumps, mutations in target enzyme, decreased ergosterol content
21
Q
fluconazole
A
- azole, triazole
- MOA: bind enzyme responsible for converting lanosterol to ergosterol–> leaky cell membrane
- use: 1st choice candidiasis, cryptococcosis, and coccidiomycosis; 2nd choice histoplasmosis, blastomycosis, sporotrichosis
- systemic activity, CNS penetration
- adverse effect: lowest level of inhibition of liver cytochrome P450 enzymes
- resistance: efflux pumps, mutations in target enzyme, decreased ergosterol content
22
Q
itraconazole
A
- azole, triazole
- MOA: bind enzyme responsible for converting lanosterol to ergosterol–> leaky cell membrane
- use: blastomycosis, coccidiomycosis, histoplasmosis, sporotrichosis, Aspergillus, Candida, dermatophyte, onychomycosis
- systemic activity
- requires low pH for absorption (impaired by antacids)
- adverse effect: inhibition of liver cytochrome P450 enzymes
- resistance: efflux pumps, mutations in target enzyme, decreased ergosterol content
23
Q
voriconazole
A
- azole, triazole
- MOA: bind enzyme responsible for converting lanosterol to ergosterol–> leaky cell membrane
- use: Candida, dimorphic fungi, aspergillosis (treatment of choice)
- systemic activity
- adverse effect: inhibition of liver cytochrome P450 enzymes, blurred vision, photophobia, altered perception of color
- resistance: efflux pumps, mutations in target enzyme, decreased ergosterol content
24
Q
posaconazole
A
- azole, triazole
- MOA: bind enzyme responsible for converting lanosterol to ergosterol–> leaky cell membrane
- use: Candida, dimorphic fungi, Aspergillus, mucormycoses, Cryptococcus
- systemic activity
- take with fatty meal
- adverse effect: strong inhibition of liver cytochrome P450 enzymes
- resistance: efflux pumps, mutations in target enzyme, decreased ergosterol content
25
Q
flucytosine
A
- originally anti-neoplastic agent
- analog of cytosine
- MOA: converted to 5-FU–> incorporated into RNA–> disrupt protein synthesis or inhibit DNA synthesis
- use: systemic infections, Cryptococcus, Candida
- adverse reaction: bone marrow suppression, anemia, leukopenia, thrombocytopenia, hepatotoxicity, GI intolerance
- resistance: altered metabolism of flucytosine
26
Q
echinocandins
A
- lipopeptides
- MOA: inhibit synthesis of beta-glucans–> weakened cell wall–> osmotic stress
- use: Candida, Aspergillus, non-responsive organisms
- IV, poor CNS penetration, $$
- adverse effects: well tolerated, drug interactions
27
Q
griseofulvin
A
- oral agent to treat dermatophyte infection
- MOA: interfere with microtubule function–> interfere with mitosis
- admin microcrystalline form, improved with fatty meals
- concentrates in keratin precursor cells
- replaced by newer drugs
- side effects: headache, decreased effectiveness of oral contraceptives
28
Q
allylamines
A
- oral systemic drugs for cutaneous and mucocutaneous infection
- MOA: inhibit enzyme of squalene epoxidase–> inhibit ergosterol synthesis–>damaged cell membrane
- terbinafine= topical or oral for onychomycosis and other dermatophyte infections
- adverse effects: rare
29
Q
nystatin
A
- topical antifungal
- polyene
- MOA: binds ergosterol
- use: Candida, oropharyngeal, vaginal candidiasis
30
Q
clotrimazole
miconazole
A
- topical azole
- OTC drugs
- use: vulvovaginal candidiasis, oral lozenges for thrush, tinea corporis, tinea, pedis, tinea cruris
31
Q
terbinafine
naftifine
A
- topical allylamines
- use: tinea cruris (jock itch), tinea corporis (ringworm), pityriasis
