Anti Fungal and Parasitics

Question 1

Amphotericin B

Answer 1

Makes pores by binding ergosterol in the yeast membrane

Nephrotoxity

Question 2

Micafungin

Answer 2

Inhibits Beta-glucan synthase complex, preventing cross-linking in yeast cell-wall

Question 3

Fluconazole

Answer 3

Inhibits 14alpha-demethylase; prevents production of ergosterol

GI symptoms

Azoles inhibit Cytochrome p450 and cause drug-drug interactions

Question 4

Vuriconazole

Answer 4

Inhibits 14alpha-demethylase; prevents production of ergosterol

Transient visual disturbances

Azoles inhibit Cytochrome p450 and cause drug-drug interactions

Question 5

Flucytosine

Answer 5

Prodrug converted by yeast cytosine deaminase to 5-FU, inhibiting thymidylate synthetase preventing DNA and RNA synth

Rare reversible bone marrow depression, hepatoxicity

Extreme caution in hepatic impaired patients

Question 6

Terbinafine

Answer 6

Inhibits squalene epoxidase leading to accumulation of squalene which is toxic in yeast

GI distress

Question 7

Artemether and Artesunate

Answer 7

Binds Iron and breaks down peroxide bridges, generating free radicals toxic to parasite proteins

Type 1 hypersensitivity

Chloroquine-resistant strains

Fast acting and short half-life (use in combo with longer acting drugs)

Question 8

Doxycycline

Answer 8

Inhibits protein synthesis

GI discomfort and candidiasis

Prophylactic for chloroquine resistant P falciparum

Slow acting (combo with fast acting drug)

Question 9

Primaqiune

Answer 9

Generates ROS, interfering with parasite electron transport chain

GI distress

Liver stage hypnozoites of P. vivax and P. ovale

Causes hemolytic anemia in G6PD-deficient patients

Question 10

Chloroquine

Answer 10

Prevents heme polymerization to non-toxic hemozoin, leading to toxic levels of free heme

Headaches, GI distress, High doses cause retinopathy

Malaria-prophylaxis, and treatment of blood stage

Question 11

Pyrimethamine

Answer 11

Inhibits protozal DHFR

Blood forms of chloroquine resistant P. falciparum, toxoplasmosis

Given with sufladoxine in fixed dose tablet

Question 12

Sulfadoxine

Answer 12

Inhibits dihydropteroate synthase

Question 13

Metronidazole

Answer 13

Produces toxic free radicals, forming reduced intermediates leading to DNA damage

GI distress, dizziness, peripheral neuropathy

giardia and entamoeba

Question 14

Albendazole

Answer 14

binds beta-tubulin, inhibiting tubilin polymerization and microtubule dependent glucose uptake

abdominal pain, nausea, vomiting, neutropenia with prolonged use

broad spectrum: ascariasis, hookworm, pinworm

Question 15

Ivermectin

Answer 15

Opens glutamate sensitive chloride channels, leading to parasite paralysis and death

Reaction to dying worms adverse effect

onchocerciasis, strongyloidiasis

Question 16

Praziquantel

Answer 16

Increases cell membrane permeability to calcium, causing strong contractions and paralysis of worm muscles

Headaches, GI distress, dizziness, drowsiness

schistomiasis, intestinal tapeworms, cysticercosis