Exam 9: Antihelminthic and Antiprotozoal Drugs Flashcards Preview

Pharmacology > Exam 9: Antihelminthic and Antiprotozoal Drugs > Flashcards

Flashcards in Exam 9: Antihelminthic and Antiprotozoal Drugs Deck (37)
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1
Q

Name 3 antihelminthic drugs?

A
  1. Albendazole
  2. Pyrantel
  3. Praziquantel
2
Q

Name 4 antiprotozoal drugs?

A
  1. Metronidazole
  2. Iodoquinol
  3. Paromomycin
  4. Nitazoxanide
3
Q

What are 2 drugs used to treat pinworm (Enteriobius vermicularis)?

A
  1. Albendazole

2. Pyrantel

4
Q

What are 2 considerations when treating pinworm?

A
  1. treatment works well when the patients adheres to strict personal hygiene standards
  2. Treat both the patient and their family members
    (Remember, treat with Albendazole and Pyrantel)
5
Q

What drug is used to treat asymptomatic or mild Ascariasis? Severe?

A

Mild/Asymptomatic: Albendazole

Severe: Pyarntel pamoate

6
Q

What drug is used to treat Necator americans (hookworm)?

A

Albendazole

7
Q

What drug is used to treat Taenia solium and saginata?

A

Praziquantel

8
Q

What is an adjunctive therapy you can use when treating Taenia solium with Praziquantel?

A

Treatment can result in release of embryos from eggs and result in cysticercosis, so you may want to treat with a purgative (laxative) like Magnesium sulfate.

9
Q

What 2 antihelminthic drugs are used to treat Neurocysticercosis?

A

Albendazole and Praziquantel

10
Q

What non-antihelminthic drug is used in the treatment of Neurocysticercosis?

A

Dexamethasone

give it 1-2 days before treatment and 4-7 days after treatment ends.

11
Q

What is a pharmacokinetic consideration with Albendazole?

A

It has to be metabolized in the liver to Albendazole sulfoxide to be active.

12
Q

What is the mechanism of Albendazole?

A

Binds to Beta-tubulin, causing inhibition of microtubule polymerization and therefore a decrease in microtubule-dependent glucose uptake by the parasite.

13
Q

Why is Albendazole selective against helminths?

A

It does not bind well to mammalian Beta-tubulin

14
Q

What are adverse effects of Albendazole?

A

GI stuff (most frequent)
Teratogenic
Hepatotoxicity/Increased liver enzymes
Leukopenia (perform blood counts every 2 weeks)

15
Q

What is the mechanism of Pyrantel?

A

Activation of cholinergic nicotinic receptors in nematode muscles, causing a depolarizing neuromuscular blockade (human receptors are different, so it doesnt have this effect)

16
Q

What are adverse effects of Pyrantel?

A

GI problems (most frequent)
Headache, dizziness, drowsiness
Use with caution in patients with liver failure, pregnant women, and kids under 2.

17
Q

What is the mechanism of praziquantel?

A

Causes an increase in Ca+ influx, inducing muscle contracture and paralysis, dislodging the suckers
(Little effect on human muscle)

18
Q

What are two types of bugs that Praziquantel can be used for?

A

Schistosomes (trematodes)

Tapeworms (cestodes)

19
Q

Adverse effects of Praziquantel?

A

Dizziness, drowsiness, headache, AMS (most common)
GI problems
Increased liver enzymes
Low grade constitutional symptoms several days after therapy.
Avoid in pregnancy (caused abortions in rats)

20
Q

Where can intestinal Entamoeba infections spread and cause?

A

Liver, abscesses

21
Q

What 2 drugs are used to treat asymptomatic carriers of Entamoeba histolytica?

A

Iodoquindol and Paromomycin

22
Q

What drug is used to treat symptomatic Entamoeba infections?

A

Metronidazole, followed by Iodoquinol or Paromycin

23
Q

What 2 drugs are preferred for Giardiasis?

A

Metronidazole and Nitazoxanide

24
Q

Who gets treated with Trichomoniasis?

A

Infected woman and her sexual partner(s) to prevent recurrence

25
Q

What drug is used to treat Trichomoniasis?

A

Metronidazole

26
Q

What two drugs are used to treat Cryptosporidium?

A

Paromomycin and Nitazoxamide

27
Q

What is the mechanism of Metronidazole?

A

Inhibits DNA synthesis

Nitro group gets reduced, binds to intracellular macromolecules like DNA, inhibits DNA synthesis.

28
Q

Adverse effects of Metronidazole?

A

Disulfiram-like reaction with alcohol
Nausea, headache, metallic taste
Carcinogenic in first trimester

29
Q

Where is Iodoquinol effective?

A

GI tract, because it’s not well absorbed.

30
Q

Adverse effects of Iodoquinol?

A

Neurotoxicity (optic neuritis, loss of vision)

GI upset

31
Q

Where is Paromomycin effective?

A

GI tract, because it’s not well absorbed.

32
Q

What is the mechanism of Paromomycin?

A

It is an aminoglycoside

Binds to the 30S ribosomal, inhibiting protein synthesis

33
Q

What are adverse effects of Paromomycin?

A

Ototoxicity, nephrotoxicity (aminoglycoside)

Go side effects

34
Q

What is a pharmacokinetic consideration of Nitazoxanide?

A

Must be hydrolyzed into an active form (tizoxanide)

35
Q

What is the mechanism of Nitazoxanide?

A

Inhibits pyruvate:ferredoxin 2-oxidoreductase enzyme dependent electron transport reaction
Interfering with anaerobic energy metabolism

36
Q

What are uses of Nitazoxanide?

A

Diarrhea caused by Cryptosporidium in immunocompetent children 1-11, adolescents, and adults.

37
Q

What is an advantage of Nitazoxanide over Metronidazole?

A

Doesnt have mutagenic/carcinogenic effects