Antiparasitic drugs (Most important)

Question 1

Metronidazole - Classification

Answer 1

Nitromidazole compound, tissue amebicide

Question 2

Metronidazole - MoA

Answer 2

It inhibits nucleic acid synthesis by disrupting the DNA of microbial cells.

Inhibit pyruvate-ferredoxin oxidoreductase (PFOR)

Question 3

Metronidazole - Clinical use

Answer 3

Entamoeba histolytica
Giardia intestinalis (Giardia lamblia)
Trichonomas vaginalis

Anaerobic bacteria:
Bacteroides fragilis
Helicobacter pylori
Clostridium difficle

Amebiasis
Giardiasis
Trichonomiasis

Dracunculiasis by Dracunulus medinensis (Guinea worm infection)
Enterocolitis
Rosacea (acne rosacea)

Question 4

Metronidazole - Contraindications

Answer 4

Contraindicated during first trimester of pregnancy

Question 5

Metronidazole - Adverse effects

Answer 5

Metallic taste
Transient leukopenia
Thrombocytopenia

Question 6

Metronidazole - Interactions

Answer 6

Increased effect of warfarin.

Ethanol: disulfiram-like reaction

Serum levels affected by drugs inhibiting/inducing CYP3A4.

Question 7

Drugs for malaria

Answer 7

Quinine
Chloroquine 
Mefloquinine 
Primaquine 
Artesunate
Artemether 
Atovaquone
Proguanil 
Pyrimethamine
Sulfadoxine

Question 8

Quinine, Chloroquine, Mefloquinine - MoA

Answer 8

Inhibits nucleic acid synthesis/function during erythrocytic schizogony

Question 9

Quinine - Clinical use

Answer 9

Alternative to artesunate for severe malaria

Question 10

Chloroquine - Clinical use

Answer 10

P. falciparum, prevention and treatment

Combination with primaquine to eradicate P. vivax

Question 11

Chloroquine - Contraindications

Answer 11

Should be used cautiously in pregnant women because fetal damage has been reported

Question 12

Chloroquine - Adverse effects

Answer 12

Toxic overdose: Retinal damage and blindness

Exacerbation of psoriasis and pruritus

Question 13

Mefloquinine - Clinical use

Answer 13

Prophylaxis and treatment of falciparum malaria, where it is known to be effective

Combination with artesunate is a first-line therapy in parts of Southeast Asia and South America

Question 14

Mefloquinine - Adverse effects

Answer 14

Severe neuropsychiatric syndrome characterized by hallucinations, anxiety, confusion, seizures and coma

Leukopenia
Thrombocytopenia
Bradycardia and arrythmias

Question 15

Primaquine - Classification

Answer 15

Aminoquinoline derivative

Question 16

Primaquine - MoA

Answer 16

Form quinones that oxidize and destroy schizont membranes

Question 17

Primaquine - Clinical use

Answer 17

P. vivax and P. ovale in combination with chloroquine or other drugs

Question 18

Primaquine - Contraindications

Answer 18

G6PD deficiency

Question 19

Primaquine - Adverse effects

Answer 19

Hemolytic anemia in G6PD deficiency

Question 20

Artesunate, Artemether - MoA

Answer 20

Form free radicals that attack heme and proteins in malarial parasites and inhibit erythocytic schizogony

Question 21

Artesunate - Clinical use

Answer 21

IV is 1st line for severe falciparum malaria (children + adults)
P. vivax

Question 22

Artemether - Clinical use

Answer 22

P. falciparum malaria

P. vivax

Question 23

Atovaquone - MoA

Answer 23

Inh synthesis of pyrimidines and nucleic acid synthesis by selective inhibition of mitochondria electron transport in plasmodia

Question 24

Atovaquone - Clinical use

Answer 24

Prophylaxis and treatment of Chloroquine-resistant falciparum malaria in combination with proguanil or doxycycline

Alone: pneumocystitis jiroveci infections

Question 25

Proguanil - MoA

Answer 25

Inh synthesis of pyrimidines and nucleic acid synthesis by inhibiting folate reductase

Question 26

Proguanil - Clinical use

Answer 26

Prophylaxis and treatment of Chloroquine-resistant falciparum malaria in combination with atovaquone

Question 27

Pyrimethamine, Sulfadoxine - MoA

Answer 27

Inhibit folic acid synthesis

Question 28

Pyrimethamine, Sulfadoxine - Clinical use

Answer 28

Malaria

Toxoplasmosis (with sulfadiazine)

Question 29

Pyrimethamine, Sulfadoxine - Adverse effects

Answer 29

Skin rashes

Megaloblastic anemia and other hematologic reactions

Question 30

Drugs for toxoplasmosis

Answer 30

Pyrimethamine + sulfadiazine

Spiramycin

Question 31

Pyrimethamine + sulfadiazine - Clinical use

Answer 31

Toxoplasmosis in AIDS

Question 32

Spiramycin - Classification

Answer 32

Macrolide

Question 33

Spiramycin - Clinical use

Answer 33

Fetal toxoplasmosis

Question 34

Pyrimethamine + sulfadiazine - Adverse effects

Answer 34

Folate deficiency and hematologic abnormalities

Question 35

Pyrimethamine + sulfadiazine - Interactions

Answer 35

Leucovorin (folic acid) can be added to reduce the hematologic effects of these drugs

Question 36

Albendazole - Classification

Answer 36

Benzimidazole compound

Question 37

Albendazole - MoA

Answer 37

Binds β-tubulin and inhibit its polymerization to form microtubules in the parasites. Makes it impossible for them to obtain glucose.

Question 38

Albendazole - Clinical use

Answer 38

Intestinal nematode infections (ascariasis, capillariasis, hookworm inf, pinworm inf, whiphworm inf)

Trichinosis (combo with corticosteroid to relieve inflamation)

Cysticercosis, echinococcosis, microsporidiosis

Question 39

Albendazole - Contraindications

Answer 39

Contraindicated during pregnancy because of potential to inhibit mitosis and impair fetal development

Question 40

Albendazole - Adverse effects

Answer 40

Well tolerated

High doses: Hepatitis, hemtologic toxicity

Question 41

Albendazole - Interactions

Answer 41

Increased absorption with high fat meal

Question 42

Pyrimethamine - Contraindications

Answer 42

Folate deficiency anemia (Vitamin B9)