Term
| What are 5 types of protozoa? |
|
Definition
1. malaria
2. amebiasis
3. giardiasis
4. trichomoniasis
5. toxoplasmosis |
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|
Term
| What are 3 types of helminths? |
|
Definition
1. nematodes (worms)
2. trematodes (flukes)
3. cestodes (tapeworms) |
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Term
| What are two types of ectoparasites and where do they live? |
|
Definition
1. pediculosis (lice)
2. scabies (mites)
live on skin or hair shafts |
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Term
| What species causes most cases of malaria? |
|
Definition
most cases caused by Plasmodium falciparum and P. vivax
other species P. ovale and P. malariae |
|
|
Term
| Where do endoparasites live and what are the two categories of them? |
|
Definition
live in lumen, tissue, or blood.
Protozoa and Helminths |
|
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Term
| What three things are involved in the life cycle of malaria? |
|
Definition
| mosquito, human liver, erythrocytes |
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Term
| In malaria, what action leads to symptoms of fever, chills, joint pain, and headache? |
|
Definition
| periodic rupture of merozoites from erythrocytes into bloodstream along with other pyrogens |
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Term
| What phase of malaria is not affected by drugs? |
|
Definition
| sporozoites from mosquitos |
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Term
| What is the only drug able to eradicate tissue (liver) plasmodia? |
|
Definition
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Term
| When malaria does asexual multiplication in the liver it is called ______ and when they replicate in red blood cells it is called ______. |
|
Definition
Exoerythrocytic schizogeny in liver
Erythrocytic schizogeny in red blood cells |
|
|
Term
| How do you prevent erythrocytic schizogeny? |
|
Definition
Chloroquine
most drugs work in this stage |
|
|
Term
| What are three types of therapy for malaria? |
|
Definition
1. Suppressive therapy (prophylaxis): drugs depend on region being visited
2. Treatment of acute attack: drugs depend on type of malaria identified
3. Prevention of relapse (radical cure): only after patient leaves endemic area
DRUG RESISTANCE VARIES BY GEOGRAPHIC REGION |
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|
Term
| What type of malarial infection is the most severe? |
|
Definition
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|
Term
| What two Plasmodium species can persist in liver and cause relapse? |
|
Definition
|
|
Term
| What is the prophylaxis and treatment regimen for malaria using Chloroquine? |
|
Definition
Prophylaxis: 500mg once a week starting 1-2 weeks before travel
Treatment: 1 gm, then 500mg at 6, 24, and 48 hours |
|
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Term
| What is the drug of choice for chloroquine resistant strains of Plasmodium? |
|
Definition
Quinine sulfate
Dose: 650mg TID x 3-7 days
immediate onset
Used in combo with doxycycline, tetracycline, or clindamycin for 3-7 days |
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Term
| Which drug's AE are GI symptoms, cinconism, hypoglycemia, and BLACKWATER FEVER? |
|
Definition
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|
Term
| What is a possible hypersensitivity reaction causing massive hemolysis, hemoglobinemia, and hemoglobinuria, caused by Quinine sulfate? |
|
Definition
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|
Term
| What is the only generic quinine product not taken off the market in 2007? |
|
Definition
| Qualaquin - only approved for malaria. $5/tablet |
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|
Term
| Which drug is a stereoisomer of quinine and is the drug of choice for severe, life threatening malaria? |
|
Definition
Quinidine gluconate
only parenteral antimalarial drug |
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Term
| Which drug is a class 1a antiarrhythmic agent and a potent inhibitor of CYP 2D6 enzyme? |
|
Definition
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|
Term
| Which drug is a combination of atovaquone and proguanil, is a 1st line agent for prophylaxis against chloroquine-resistant Plasmodia and 2nd line for treatment when unable to use quinine? |
|
Definition
Malarone
- also effective for primary liver stage of P. falciparum
- give with meals for 3 days |
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|
Term
| Which drug is a combination of pyrimethamine and sulfadoxine, is a folic acid antagonist, is associated with severe sulfa rxns and is no longer recommended by CDC? |
|
Definition
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|
Term
| Which drug is chemically related to quinine and is used for prophylaxis and treatment of chloroquine-resistant Plasmodia with a T1/2 of 20 days? |
|
Definition
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|
Term
| Which drug's AE of neuropsychiatric syndrome makes it a 3rd line defense for treatment of Plasmodia and has drug interactions which could lead to cardiac arrest? |
|
Definition
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|
Term
| What is the only drug for prevention of relapse from P. vivax and P. ovale infections? |
|
Definition
primaquine - 15mg/day x 14 days
- use with either chloroquine or quinine |
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|
Term
| Which drug's AE are abd cramps, nausea, and hemolytic anemia and pts must be screened for G6PD deficiency before its use? |
|
Definition
|
|
Term
| What is the most common inherited error of metabolism? |
|
Definition
| Glucose-6-Phosphate Dehydrogenase deficiency |
|
|
Term
| What does having low G6PD lead to? |
|
Definition
| hemolysis of RBCs by 3rd day of drug therapy leading to hemolytic anemia, also urobilinogen in urine and increase in indirect bilirubin |
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|
Term
|
Definition
| preserves glutathione in reduced form in RBCs and prevents hemoglobin from being oxidized to methemoglobin by certain oxidizing drugs (primaquine, quinine, sulonamides, etc) |
|
|
Term
| What populations are susceptible to G6PD deficiency? |
|
Definition
African-Americans 10%
Eastern Mediterranean origin up to 50%
Southeast Asians 5% |
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|
Term
| What disease involves the ingestion of cysts in contaminated food and water leading to ulceration of the bowel and amebic dysentery or liver abscesses from entry through the portal vein? |
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Definition
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|
Term
| What are poorly absorbed drugs used to treat asymptomatic disease of amebiasis? |
|
Definition
|
|
Term
| What are two luminal amebicides? |
|
Definition
1. Iodoquinol - take with meals to limit GI toxicity
2. Paromomycin - an aminoglycoside |
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|
Term
| What are the drugs of choice for invasive amebiasis? |
|
Definition
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|
Term
| What are two tissue amebicides? |
|
Definition
1. Metronidazole (Flagyl) - 750mg po tid x 10 days
2. Tinidazole (Tindamax) - 2gm po qd x 3 days |
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|
Term
| What drug is a nitroimidazole compound well absorbed from GI tract and widely distributed to most tissues including the brain? |
|
Definition
Metronidazole (Flagyl)
drug and metabolites excreted in urine T1/2 = 8hrs |
|
|
Term
|
Definition
| intracellular conversion to toxic nitro radical by process unique to anaerobic bacteria and protozoans results in cell death by destruction of DNA |
|
|
Term
| What is Flagyl active against? |
|
Definition
- protozoa causing amebiasis, giardiasis, trichimoniasis
- most anaerobic bacteria including Bacteroides fragilis, Clostridia difficile, and Peptostreptococcus |
|
|
Term
| What is Flagyl's pregnancy category? |
|
Definition
Category B for 2nd and 3rd trimester
contraindicated during 1st trimester |
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|
Term
|
Definition
| nausea, headache, dry mouth, metallic taste |
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|
Term
| What are Flagyl's drug interactions? |
|
Definition
Warfarin - incresae in INR
Ethanol - acetaldehyde poisoning resulting in flushing, nausea, vomiting, and throbbing headache |
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|
Term
| What is a 2nd gen nitroimidazole, is active against some metronidazole resistant strains of Trichomonas, and has a long T1/2 so can be used as a single dose against Giardia? |
|
Definition
Tinidazole (Tindamax)
pregnancy category C, expensive, rarely used |
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Term
| What infection causes acute and chronic diarrhea secondary to ingestion of Giardia lamblia, usually from contaminated water? |
|
Definition
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|
Term
| How do you treat giardiasis? |
|
Definition
Metronidazole - 250mg tid x 7 days
Tinidazole - single dose of 2gm |
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|
Term
| What is the protozoa that causes Trichomoniasis and how do you treat it? |
|
Definition
STD due to Trichomonas vaginalis
Tx: metronidazole or tinidazole 2gm x 1 dose |
|
|
Term
| What is an opportunistic infection in AIDS pts that is treated with pyrimethamine + sulfadiazine? |
|
Definition
| Toxoplasmosis (Toxoplasma gondii infection) |
|
|
Term
| What is an AE of purimethamine + sulfadiazine? |
|
Definition
| potent inhibitors of dihydrofolate reductase and can induce folate deficiency. must add daily leucovorin (folinic acid) to prevent anemia |
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|
Term
| What is the most common helminthic infection in the US and has symptoms of perianal itching and inflammation? |
|
Definition
| pinworm (enterobiasis) which is a nematode |
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|
Term
| What is the 2nd leading cause of morbidity from parasitic diseases and uses a snail as a vector? |
|
Definition
| Schistosomiasis which is a trematode (fluke) |
|
|
Term
| What leaves "noodle-like" objects in the stool, is acquired by ingestion of poorly cooked meat or fish, and can be 20-30 feet long? |
|
Definition
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|
Term
| What drug is used for nematode infections and works by inhibiting microtubule function and depleting glycogen stores leading to worm death? |
|
Definition
mebendazole (Vermox)
- poorly absorbed so little systemic AE |
|
|
Term
| What is the dose of mebendazole (Vermox) to treat nematode infections? |
|
Definition
| single 100mg dose and repeated in 2 weeks |
|
|
Term
| What is an OTC product for nematode infections and is a depolarizing neuromuscular blocking agent leading to paralysis of helminths? |
|
Definition
| pyrantel pamoate (Antiminth, Pin-X) |
|
|
Term
| What is the dose of pyrantel pamoate (Antiminth, Pin-X) to treat nematode infections? |
|
Definition
single dose of 11mg/kg, repeated in 2 weeks
AE: some GI upset, h/a, fever |
|
|
Term
| What drug is used for schistosomiasis, flukes, and tapeworms and increases cell membrane permeability and eventual disintegration of parasite? |
|
Definition
| praziquantel (Biltricide) |
|
|
Term
| What is the dose and AE of praziquantel (Biltricide) when used for helminthic infections? |
|
Definition
dose 20 mg/kg/dose BID-TID x 1 day
- pts be advised to swallow tablets whole and avoid driving for 2 days
AE: malaise, h/a, dizziness, drowsiness |
|
|
Term
| What infection involves oval eggs (nits) which hatch to produce nymphs which evolve into adults, both of which feed on the host's blood which results in severe itching? |
|
Definition
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|
Term
| What treatment for lice and scabies is an extract of chrysantemum flower and is in OTC products such as RID? |
|
Definition
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|
Term
| What is the drug of choice for lice and scabies? it is a synthetic derivative of pyrethrin and acts on nerve cell membranes to paralyze ectoparasites. |
|
Definition
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|
Term
| What is the dose of permethrin used for lice and scabies? |
|
Definition
HEAD LICE: 1% liquid rinse (NIX) one time, must remove nits after
SCABIES: 5% cream (Elimite) |
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|
Term
| What drug for lice and scabies can be absorbed and cause neurologic toxicity including tremor, ataxia, insomnia, and seizures and so should be avoided by young children, during pregnancy, and with any concurrent skin inflam that can lead to increased absorption? |
|
Definition
Lindane 1% (Kwell)
- available as lotion or shampoo
- less effective than permethrin |
|
|
Term
| What drug (cream or lotion) is used for scabies only? |
|
Definition
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