Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

BIOM*40909 > Parasitic Infections > Flashcards

Parasitic Infections Flashcards

1
Q

Major targets for chemotherapy for parasitic infections:

A
  1. Unique essential molecule found only in the parasite
  2. Similar molecules found in both the host and parasite but indispensable for the parasite only
  3. Common biochemical functions found in both parasite and host but with different pharmacological properties
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Categories of parasites found in humans:

A
  • Macroscopic (ringworm, tapeworm, head louse)
  • Microscopic (trichomonas, malaria, beaver fever)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Two examples of taenia species which can affect humans:

A
  • Taenia saginata (beef tapeworm) and taenia solium (pork tapeworm)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How do pigs and cows get infected with tapeworm?

A
  • Parasite eggs get released into environment
  • Get infected when ingesting vegetation that has been contaminated
  • Oncospheres hatch and penetrate the intestinal wall of the intermediate host
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Where does the parasite attach within the host/intermediate host?

A
  • Scolex (worm’s head) attaches to the intestine, matures, produces more eggs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What does praziquantel treat?

A

Targets and treats parasitic worms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is praziquantel?

A

A synthetic isoquinoline derivative

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Praziquantel bioavailability after oral dosing?

A

80%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

MOA of praziquantel:

A

Exact unknown, but it binds to the integument of the parasite and produces focal vacuolization

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Drug of choice against cestode infections:

A
  • Praziquantel
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Pros of praziquantel:

A
  • Safe and effective
  • Single oral dose
  • Impairs the function of hooks and suckers at the anterior end of the worm
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

When is the bioavailability of praziquantel diminished?

A

When taken concurrently with corticosteroids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Adverse reactions of praziquantel:

A

Nausea, headaches, abdominal discomfort

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is niclosamide?

A

Salicylanilide derivative used to treat parasitic worms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

MOA of niclosamide:

A

Rapidly killing scolex and producing segments of adult tapeworms
- Inhibition of mitochondrial anaerobic phosphorylation of ADP results in a decrease in ATP production

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the second line choice of treatment for parasitic worms?

A

Niclosamide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Administration of niclosamide:

A

Single oral dose tablet, chewed thoroughly and swallowed with water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Adverse effects of niclosamide:

A

GI complaints
- Avoid alcohol for 24 hours

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Common name of enterobius vermicularis:

A

Pinworm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Life cycle of pinworms:

A
  • Eggs on perinanal folds that contain larvae which mature in 4-6 hours
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

How does a human get infected with pinworms?

A
  • Ingesting embryonated eggs which hatch in the small intestine, adults form in the lumen of the cecum
  • Eggs can also contaminate nightclothes and bedding
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Drugs of choice for pinworm:

A

Mebendazole and pyrantel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is mebendazole?

A

Broad spectrum drugs effective against parasites

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

How do you administer mebendazole?

A

Administered orally
- Less than 10% absorbed
- Absorption can be increased if ingested with a fatty meal
- Twice over a two week interval

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

MOA of mebendazole:

A
  • Binds to B-tubulin and inhibits polymerisation to microtubules
  • This inhibits parasite motility, glucose uptake and cell division
  • Once parasite is killed, it is expelled in feces
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Do not administer mebendazole if…

A

Pregnant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Pyrantel class:

A

Tetrahydropyrimidines

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

MOA of pyrantel:

A
  • Poorly absorbed within the gut
  • Acts selectively at neuromuscular junctions of parasites on nicotinic acetylcholine receptors
  • This causes the release of ACh and inhibition of acetylcholinesterase
  • Results in paralysis of worms
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Differences between pyrantel and mebendazole

A

Pyrantel has a narrower spectrum of activity than mebendazole

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Adverse effects of pyrantel:

A

Mild, nausea, vomiting, diarrhea

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Common name of pediculus capitis:

A

Head lice

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

How do head lice grow and mature?

A

Feeding on human blood

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Treatment for head lice:

A

Permethrin, Malathion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Class of permethrin:

A

Phyrethroids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

MOA of permethrin:

A

Causes voltage-gated sodium channels to remain open which causes membrane depolarization and rapid paralysis in the parasite
- Absorbed through the skin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Class of malathion

A

organophosphate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

When is malathion used?

A

In cases where permethrin fails due to resistance

38
Q

MOA of malathion:

A
  • Irreversible inhibition of acetylcholinesterase, causes accumulation of ACh and rapid paralysis
39
Q

Adverse effects of head lice drugs (malathion and permethrin):

A

Itching, mild burning of the scalp, inflammation of the skin

40
Q

Definition of protozoa:

A
  • Eukaryotes
41
Q

Common name of entamoeba histolytica:

A

Ameobiasis

42
Q

Symptoms of ameobiasis:

A

Can range of mild diarrhea to blood and mucus in the stool
- Asymptomatic intestinal infection
- Mild to moderate colitis
- Dysentery
- Amoeboma
- Liver abscess

43
Q

Entamoeba histolytica exists in two forms:

A

Cysts and trophozoites

44
Q

Entamoeba histolytica cysts:

A

Can transform into trophozoites

45
Q

Entamoeba histolytica trophozoites:

A

Invasive, can reproduce and invade the wall of the large intestine. Can transform to cysts when excreted

46
Q

Infection of entamoeba histolytica occurs when _____ invades the ____ ____.

A

Trophozoites, intestinal epithelium

47
Q

Spread of entamoeba histolytica via the portal vein can result in ____

A

Liver abscesses

48
Q

Types of amoebicidal drugs:

A
  • Luminal amoebicides
  • Systemic amoebicides
  • Mixed amoebicides
49
Q

Luminal amoebicides treat:

A

Parasites in bowel lumen

50
Q

Systemic amoebicides treat:

A

Parasites in intestinal wall and liver

51
Q

What does metronidazole treat?

A

Trophozoites but not cysts

52
Q

What class of amoebicide is metronidazole?

A

Mixed

53
Q

What class of amoebicide is iodoquinol?

A

Luminal

54
Q

Side effects of iodoquinol:

A

Rash, diarrhea, dose-related peripheral neuropathy

55
Q

Metronidazole eliminates trophozoites in which areas of the body?

A
  • Liver abscess
  • Intestinal wall
  • NOT gut lumen
56
Q

Metronidazole is a derivative of:

A

Nitroimidazole

57
Q

Metronidazole can be administered:

A

Orally and is readily absorbed

58
Q

How is metronidazole distributed:

A

Tissue distribution via simple diffusion

59
Q

Metabolism of metronidazole:

A

Hepatic oxidation by mixed-function oxidase, followed by glucuronylation

60
Q

How is metronidazole excreted:

A

Urine

61
Q

Side effects of metronidazole:

A

Nausea, vomiting, headache, abdominal cramps, metallic taste in mouth

62
Q

What is giardia lamblia?

A

Beaver fever

63
Q

Two life-cycle stages of beaver fever:

A

Trophozoites and cysts

64
Q

Infection of beaver fever occurs following:

A

Ingestion of contaminated water

65
Q

Two types of beaver fever:

A

People-specific and zoonotic

66
Q

Prescription for beaver fever:

A

Metronidazole

67
Q

Is trichomonas trophozoites or cysts?

A

Trophozoites, does not have a cyst form

68
Q

Common symptoms of trichomonas:

A

Women: Vaginal discharge, vulvar itching, discomfort in urination
Men: No signs or symptoms, occasional urethral discharge and burning post urination

69
Q

Treatment plans for trichomonas:

A

Metronidazole, single or multiple dose regimens

70
Q

What treatment plan can be done for trichomonas resistant to metronidazole?

A

Repeat treatment at higher doses

71
Q

Systemic treatment or topical treatment for trichomonas?

A

Systemic due to multifocal nature of the infection

72
Q

Human malaria is caused by:

A

P. falciparum, P. vivax, P. malariae, P. knowlesi

73
Q

Most serious strain of malaria resulting in most deaths:

A

P. falciparum

74
Q

Treatment for malaria is dependent on:

A

Liver stage- tissue schizonticides
Erythrocytic stage- blood schizonticides
Sexual stages- Gametocides

75
Q

In humans, sporozoites leave the blood and multiply in the ____ forming _____

A

Liver, tissue schizonts

76
Q

Treatment of malaria is dependent on ____

A

Species that caused the infection

77
Q

P. falciparum and P. malariae treatment:

A
  • One cycle of multiplication in liver
  • Liver infection ceases in less than 4 weeks
  • Elimination of erythrocytic parasites cures infection
78
Q

P. vivax and P. ovale:

A
  • Dormant hepatic stage (hypnozoite) not killed by most drugs
  • Must eliminate both erythrocytic and hepatic parasites
79
Q

According to the CDC, most malaria drugs are:

A

Chemoprophylaxis recommendations (chloroquine, mefloquine, doxycycline)

80
Q

Chloroquine is the drug of choice for ___

A

Chemoprophylasis, drug sensitive P. falciparum

81
Q

How is chloroquine administered:

A

Orally, rapidly absorbed and distributed to tissues where it has blood schizonticide activity

82
Q

Adverse effects of chloroquine:

A

Nausea, vomiting, blurred vision ( at high doses )

83
Q

How to reduce adverse effects of chloroquine:

A

Dosing after meals

84
Q

What is mefloquine used to treat:

A

Drug resistant P. falciparum

85
Q

How is mefloquine distributed:

A

Orally, well absorbed, extensive distribution

86
Q

Method of action of mefloquine:

A
  • Has blood schizonticide activity against P. falciparum but not against hepatic stages of gametocytes
  • Concentration in the parasite
87
Q

Adverse effects of mefloquine:

A

Neuropsychiatric toxicities, nausea, vomiting, dizzyness, sleep and behaviour disturbances

88
Q

Do not use mefloquine if:

A

History of epilepsy and other psychiatric disorders

89
Q

When is doxycycline used:

A

areas with a multidrug resistance to parasites

90
Q

MOA of doxycycline:

A

Inhibits protein synthesis, blood schizonticide activity, not active against liver stages of malaria

BIOM*40909 (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions