Ellen - Pharmacology 3: Antiprotozoals

Front 1

Name 4 protozoa endemic to N. America.

Back 1

1. Entamoeba histolytica - Amebic dysentery
2. Trichomonas vaginalis - Trichomoniasis
3. Giardia lamblia - Giardiasis
4. Toxoplasma gondii - Toxoplasmosis

Front 2

Name 4 antimalarials

Back 2

Quinine
Chloroquine
Primaquine
Antimetabolites

Front 3

Name 4 non-antimalarial antiprotozoals

Back 3

Metronidazole
Diloxanide
Nifurtimox
Suramin

Front 4

What is the incidence of malaria by the 4 different causative agents?

Back 4

P. vivax > P. falciparum > P. malariae > P. ovale (rare)

Front 5

What drug is active against plasmodium right after the mosquito bite when the schizonts are in the tissue (exoerythrocytic stage)?

Back 5

Primaquine

Front 6

What drugs are active against malaria after the merozoites enter the RBCs?

Back 6

Quinine
Chloroquine
Diaminopyrimidines
Mefloquine

Front 7

What is the mechanism of action of Quinine? Use?

Back 7

Blocks heme polymerization = heme gets to toxic concentrat. Used to treat chloroquine-resistant Plasmodium falciparum

Front 8

What are the adverse reactions of Quinine?

Back 8

Cinchonism (like salicylate poisoning), curare effect, myocardial depression, vasodilation, hemolytic anemia

Front 9

What is the mechanism of action of Chloroquine?

Back 9

Blocks plasmodial heme polymerization, increases heme concentrations. Heme is toxic to the parasites.

Front 10

What are the clinical uses of Chloroquine?

Back 10

Acute malarial attacks
Prophylaxis of malaria
Amebiasis

Front 11

What are the adverse reactions with prophylaxis use of Chloroquine?

Back 11

little toxicity (except with G6PD deficiency)

Front 12

What are the adverse reactions when using Chloroquine to treat acute malaria?

Back 12

anorexia, nausea, vomiting, headache, hemolytic anemia

Front 13

What are the adverse reactions when using Chloroquine to treat amebiasis?

Back 13

photosensitization, retinopathy, leukopenia

Front 14

What is the mechanism of action of Primaquine?

Back 14

Binds to DNA, damages mitochondria, inhibits protein synthesis

Front 15

What are the clinical uses of Primaquine?

Back 15

Used to treat latent liver forms of P. vivax and P. ovale

Front 16

What are the adverse reactions of Primaquine?

Back 16

Same as Chloroquine
Hemolytic anemia (esp with G6PD def)

Front 17

Who shouldn't get Primaquine?

Back 17

Pregos - fetus is relatively G6PD deficient.

Front 18

What is the mechanism of action of Pyrimethamine-Sulfadoxine? Use?

Back 18

Inhibits dihydrofolate reductase and folic acid synthesis. Used to treat chloroquine-resistant P. falciparum (erythrocytic stage)

Front 19

What are the adverse reactions of Pyrimethamine-Sulfadoxine?

Back 19

Same as Trimethoprim/ Sulfamethoxazole:Stevens-Johnson syndrome, kernicterus

Front 20

Uses and problems with Artemisinin derivatives?

Back 20

Used in some Asian antimalarial medications
Some resistance developing

Front 21

Clinical uses of Mefloquine?

Back 21

Like chloroquine, Useful in treating chloroquine- and Fansidar-resistant strains of malaria

Front 22

What are the adverse reactions with Mefloquine?

Back 22

usually mild and transient; nausea, vomiting, bradycardia. Serious psychiatric disturbances can occur (1:1000)

Front 23

What is the mechanism of Chologuanide?

Back 23

Antimalarial: prodrug metabolized by the liver to dihydrotriazine which is a dihydrofolate reductase inhibitor

Front 24

Explain the life cycle of Entamoeba Histolytica.

Back 24

Trophozoites get into lumen of the bowel where they form cysts in the intestinal wall which rupture, releasing trophozoites in the stool

Front 25

What is the mechanism of action of Metronidazole?

Back 25

activated to reactive reduced forms by electron transport proteins in anaerobes (eg. ferredoxin) which bind to DNA, causing strand scission and blocking DNA replication in a variety of protozoans and anaerobic bacteria.

Front 26

What are the clinical uses of Metronidazole?

Back 26

Amebiasis, trichomoniasis, giardiasis
Anaerobic bacterial infections

Front 27

What are the adverse reactions of Metronidazole?

Back 27

GI distress, seizures, neuropathy
Disulfiram effect (Converted to ketones = sick pt if on antabuse)
Potential mutagen

Front 28

What is the clinical use of indoquinol?

Back 28

An effective luminal amebacide used to treat both symptomatic individuals and asymptomatic carriers of Entamoeba histolytica

Front 29

What is the clinical use of Diloxanide Furoate?

Back 29

Luminal amebicide used to treat Entamoeba histolytica infections and carriers, mechanism unknown.

Front 30

What is the mechanism and clinical use of Nifurtimox?

Back 30

Reduction of the parent drug leads to production of toxic oxygen species which damage DNA. Used to tx Chagas.

Front 31

What is the mechanism and clinical use of Suramin?

Back 31

Drug is phagocytized by the parasite: inhibits enzymes important in energy metabolism. Used to tx African trypanosomiasis

Front 32

What is the use of Quinicrine?

Back 32

Giardia drug not avail in the US

Front 33

What is the clinical use and mechanism of Stibogluconate?

Back 33

pentavalent antimonial that may inhibit phosphofructokinase, the rate limiting enzyme in glycolysis. Used to treat leishmaniasis.

Front 34

What are the clinical uses and mechanisms of Melarsoprol and tryparsamide?

Back 34

bind to sulfhydryl groups and inhibit pyruvate kinase. Used to treat trypanosomiasis, but now replaced by suramin and nifurtimox.

Front 35

What are the adverse reactions of Suramin?

Back 35

Adverse reactions are infrequent; they include G.I. distress, neurologic complications and blood dyscrasias

Front 36

What are the adverse reactions of Nifurtimox?

Back 36

There is a high incidence of adverse reactions including G.I. distress, headache, vertigo, insomnia and rashes