Protozoa, Helminths, Ectoparasites

Front 1

What are the uses of Metronidazole?

Back 1

Trichomonas, Giardiases, Amebiasis

Infections caused by Bacteriodes fragilis, Clostridium difficile
(both anaerobic bacteria)

Front 2

What are the kinetics of Metronidazole?

Back 2

Good p.o absorption

Metabolized by the Liver & cleared by the Kidneys

Front 3

What is the MOA of Metronidazole?

Back 3

Ferrodoxins (ETC enzymes in protozoans and anaerobic bac.) donate electrons to Metronidazole

Metronidazole is transformed into a highly reactive nitro radical that attacks DNA and destroys its helical structure to cause cell death

Aerobic organisms do not produce the toxic metabolite from the prodrug Metronidazole

Front 4

What is the drug interactions of Metronidazole?

Back 4

1. Pts. taking Warfarin - inc. bleeding

2. Ethanol - if ingested while taking Metronidazole - disulfiram-like rxn
(drug inhibits acetaldehyde dehydrog)

Front 5

What are the COMMON adverse effects associated with Metronidazole?

Back 5

Headache

Metallic Taste

Front 6

What pregnancy category is Metronidazole? When should pregos avoid it?

Back 6

Cat. B

Avoid during 1st trimester

Front 7

What is the DOC for Trichomoniasis?

Back 7

Metronidazole

Female: oral & topical
Male consort: p.o. only

Cure rate: 80-90%

Front 8

What is the DOC for Giardiasis?

Back 8

Metronidazole

Front 9

What is another drug used to treat Giardiasis other than Metronidazole?

Back 9

Nitazoxanide: rapidly converted to the active metabolie Tizoaxanide

Interferes w/ Pyruvate:Ferrodoxin oxidoreductase-dependent electron transfer system which is required for anaerobic energy metabolism

Front 10

What is the DOC for Amebiasis?

Back 10

Metronidazole

*kills both the luminal and systemic organisms

Front 11

What is the drug used to treat Cryptosporidiosis?

Back 11

Nitazoxanide (NI-taz-ox-ah-nide)

Front 12

What is the route of administration and dosing interval for Chloroquine?

Back 12

p.o. once per week

Front 13

What is the therapeutic effect of Chloroquine?

Back 13

Kills the ERYTHROCYTIC stage of P. vivax, P. ovale, P. malariae, and SENSITIVE strains of P. falciparum

*some P. falciparum strains are resistant

Front 14

What effect does Chloroquine have on the the exoerythocytic (hepatic) stage of Malaria?

Back 14

None

Front 15

What is the MOA of Chloroquine?

Back 15

Prevents the polymerization of free heme into the malarial pigment Hemozoin

Free heme kills the parasite by oxidative damage of the cell membrane

Front 16

What drug has the same MOA as Chloroquine?

Back 16

Mefloquine

Front 17

What drug is a gametocide against all Plasmodium spp. and kills the HEPATIC form of P. vivax and P. ovale?

Back 17

Primaquine

Front 18

When is Primaquine often given?

Back 18

After erythrocytic form has been killed by Chloroquine

Front 19

What can Primaquine cause in patients with a glucose-6-phosphate dehydrogenase deficiency?

Back 19

Hemolytic anemia

*pts w/ deficiency cannot make NADPH which protects the cell membrane from oxidative damage; primaquine metabolites can cause oxidative damage to RBC membrane

Front 20

What patients (other than those w/ G-6-P deficiency) should you avoid the use of Primaquine in?

Back 20

Pregnant women: fetus does not have a well developed G-6-P dehydrogenase system

Front 21

Patients with a normal G-6P dehydrogenase system may develop __________________ when taking Primaquine

Back 21

methhemoglobinemia

Front 22

What is the dosing interval of Mefloquine?

Back 22

p.o. once / week

Front 23

What are the benefits of Mefloquine over other antimalarial agents?

Back 23

Suppress and cure infections caused by MDR strains of P. falciparum

*used for prophylaxis in people traveling to areas w/ MDR Malaria

Front 24

What are the S/E's of Mefloquine?

Back 24

Frequent: n/v, diarrhea, abdominal pain, dizziness, dysphoria

50% of pts: headache, ataxia, visual/auditory hallucinations, dizziness; usually mild and self-limiting

Rare = disorientation, seizures, neurotic/psychotic symptoms

Front 25

What is the radical cure for P. ovale and P. vivax?

Back 25

1. Chloraquine --> kills RBC form

2. Primaquine --> kills liver hypnozoites

Front 26

What is the dosing interval of of Atovaquone-proguanil?

Back 26

p.o. once a day

Front 27

What drug is used for the prophylaxis of chloroquine resistant malaria and for the treatment of chloroquine resistant P. falciparum?

Back 27

Atovaquone-proguanil

*the best tolerated

Front 28

What is the recommended time interval of usage of Malaria prophylaxis?

Back 28

Start 2 wks prior to travel

Continue 4 wks after leaving endemic areas

Front 29

What is the DOC for treating Toxoplasma gondii in immunocompetent patients?

Back 29

Pyrimethamine-Sulfadiazine

Front 30

What is DOC for treating Pneumocystis jiroveci?

Back 30

Trim-sulfa

*organism causes pulmonary infections in patients w/ AIDS

Front 31

What are the side effects of high doses of Trim-sulfa used to treat PCP?

Back 31

Hemolytic anemia
Leukopenia
Rash
Steven-Johnson syndrome

Front 32

What drug is the second choice of treatment for Pneumocystis jiroveci?

Back 32

Pentamidine

*less efficacious & more toxic than trim-sulfa

Front 33

_________ is the most common helminthic infection in the USA

Back 33

Pinworm

*local itching, especially severe at night, local irritation from scratching, positive cellophane tape test for eggs

Front 34

What can you treat Pinworm infections with?

Back 34

MAP

Mebendazole -- kills round & tape worms
Pyrantel pamoate -- kills round worms
Albendazole --kills all worms in mixed infections

Front 35

What is the most common helminthic infection in the world?

Back 35

Roundworm

*presents with malnutrition, bowel obstruction

Front 36

What do you treat a pt. with for a Roundworm infection?

Back 36

Albendazole

Front 37

What are the uses of Ivermectin?

Back 37

1. Single dose given twice yearly kills the filarial infection causing river blindness

2. Single dose given to livestock kills all roundworms and arthropods for 30 days

Front 38

What is the DOC for Cysticercosis infections (tapeworms)?

Back 38

Albendazole

Front 39

What is the TEXTBOOK DOC for the treatment of tapeworms?

Back 39

Niclosamide

* Niclosamide

Front 40

What is the DOC to treat Trematodes (flukes) that cause Schistosomiasis?

Back 40

Praziquantal

Front 41

What are the S/E's of Albendazole?

Back 41

Abdominal pain
Reversible alopecia
Increased AST & ALT

Front 42

What is the DOC for the treatment of Pediculosis (infestation w/ lice)?

Back 42

1% Permethrin

Front 43

What is the DOC for Scabies?

Back 43

5% Permethrin

Front 44

How is Permethrin solution used for the treatment of lice?

Back 44

Saturate hair w/ permethrin sol'n after shampooing and drying; wrap head in towel and wait 10 minutes; rinse drug from hair

Treat Clothes

Pubus: apply 1% permethrin cream for 10 minutes, rinse

Front 45

How is Permethrin solution used for the treatment of scabies?

Back 45

Scrub skin w/ warm, soapy water using a soft brush to remove mites

Apply 5% permethrin to entire body avoiding the face, mucus membranes and eyes

Wait 8-14 h before bathing

Front 46

What other drug can be taken p.o. and is very effective for the treatment of Scabies?

Back 46

Ivermectin

*NOT FDA approved
*useful in treatment of scabies in immunocompromised, patients w/ severely encrusted scabies or patients who have failed therapy w/ topical permethrin