[MEDICINAL CHEMISTRY] Antihelmintics and Antiprotozoal Agents

a. Antihelmintics

Drugs that are capable of eliminating parasitic worms or helminths

a. Antihelmintics

b. Antibacterial

c. Antifungal

a. Nematode

Roundworm

a. Nematode

b. Cestode

c. Trematode

b. Cestode

Tapeworm

a. Nematode

b. Cestode

c. Trematode

c. Trematode

Flukes

a. Nematode

b. Cestode

c. Trematode

c. Piperazine

MOA: Blocks response of ascaris muscle to acetylcholine (ACh), resulting in flaccid paralysis of the helminth.

a. Mebendazole

b. Pyrantel pamoate

c. Piperazine

d. Albendazole

b. Piperazine

Used for the treatment of pinworm (enterobiasis) and roundworm (ascariasis).

a. Niclosamide

b. Piperazine

c. Praziquantel

d. Ivermectin

c. Pyrantel pamoate

MOA: Depolarizing neuromuscular blocking agent leading to spastic paralysis of helminths.

a. Piperazine

b. Mebendazole

c. Pyrantel pamoate

d. Albendazole

b. Pyrantel pamoate

Should not be used with piperazine due to opposite effects (spastic paralysis vs. flaccid paralysis).

a. Mebendazole

b. Pyrantel pamoate

c. Thiabendazole

d. Niclosamide

c. Pyrantel pamoate

Used for the treatment of pinworm (enterobiasis) and roundworm (ascariasis).

a. Ivermectin

b. Praziquantel

c. Pyrantel pamoate

d. Diethylcarbamazine

d. Thiabendazole

MOA: Inhibits helminth-specific enzyme fumarate reductase / antimitotic / antimicrotubular

a. Mebendazole

b. Pyrantel pamoate

c. Piperazine

d. Thiabendazole

d. Thiabendazole

A broad-spectrum anthelmintic.

a. Mebendazole

b. Pyrantel pamoate

c. Piperazine

d. Thiabendazole

b. Thiabendazole

Side effect includes erythema multiforme / Stevens-Johnson Syndrome (SJS).

a. Albendazole

b. Thiabendazole

c. Niclosamide

d. Praziquantel

a. Erythema multiforme / Stevens-Johnson Syndrome (SJS)

Side effects of Thiabendazole include:

a. Erythema multiforme / Stevens-Johnson Syndrome (SJS)
b. Hepatotoxicity and nephrotoxicity
c. Cardiotoxicity and arrhythmias
d. Bone marrow suppression

c. Thiabendazole

Treatment for Strongyloides (threadworm).

a. Piperazine
b. Pyrantel pamoate
c. Thiabendazole
d. Mebendazole

c. Mebendazole

Antiox®.

a. Albendazole
b. Thiabendazole
c. Mebendazole
d. Pyrantel pamoate

b. Mebendazole

MOA: Irreversibly blocks glucose uptake → depleted glucose / antimitotic / antimicrotubular.

a. Piperazine
b. Mebendazole
c. Niclosamide
d. Praziquantel

b. Mebendazole

Broad-spectrum anthelmintic effective against whipworm, pinworm, roundworm, and hookworm.

a. Piperazine
b. Mebendazole
c. Niclosamide
d. Praziquantel

b. Albendazole

MOA: Antimitotic / antimicrotubular

a. Ivermectin
b. Albendazole
c. Piperazine
d. Pyrantel pamoate

b. Albendazole

Broad-spectrum anthelmintic.

a. Ivermectin
b. Albendazole
c. Piperazine
d. Pyrantel pamoate

d. Ivermectin

Derived from Streptomyces avermitilis.

a. Mebendazole
b. Thiabendazole
c. Albendazole
d. Ivermectin

b. Ivermectin

MOA: Stimulation of GABA receptors → blocked interneuron-motor neuron transmission.

a. Piperazine
b. Ivermectin
c. Pyrantel pamoate
d. Niclosamide

a. Albendazole

Treatment of Onchocerciasis (River Blindness) caused by Onchocerca volvulus.

a. Albendazole
b. Thiabendazole
c. Ivermectin
d. Diethylcarbamazine

a. River Blindness

Onchocerciasis is also known as _____

a. River Blindness
b. Elephantiasis
c. Loiasis
d. Guinea worm disease

c. Onchocerca volvulus

Onchocerciasis (River Blindness) is caused by _____

a. Wuchereria bancrofti
b. Loa loa
c. Onchocerca volvulus
d. Dracunculus medinensis

c. Praziquantel

MOA: Increases Ca²⁺ membrane permeability → resulting in loss of extracellular Ca²⁺ = tetanic-like contractions.

a. Albendazole
b. Ivermectin
c. Praziquantel
d. Diethylcarbamazine

b. Praziquantel

Drug of choice (DOC) in the treatment of infections caused by schistosomes (blood flukes).

a. Mebendazole
b. Praziquantel
c. Thiabendazole
d. Piperazine

c. Schistosomes (blood flukes)

Praziquantel is primarily used for which type of helminth infection?

a. Roundworm
b. Pinworm
c. Schistosomes (blood flukes)
d. Hookworm

b. Niridazole

Used for the treatment of schistosomiasis.

a. Oxamniquine
b. Niridazole
c. Praziquantel
d. Both a and b

c. Oxamniquine

MOA: Inhibits DNA, RNA, and protein synthesis.

a. Niridazole
b. Praziquantel
c. Oxamniquine
d. Ivermectin

b. Oxamniquine

Treatment of Schistosoma mansoni infection.

a. Niridazole
b. Oxamniquine
c. Praziquantel
d. Diethylcarbamazine

Drug of choice (DOC) for liver fluke (Fasciola hepatica) and lung fluke (Paragonimus westermani).

a. Praziquantel
b. Oxamniquine
c. Bithionol
d. Niridazole

b. Metrifonate

An organophosphate compound used as an alternate drug for the treatment of urinary schistosomiasis.

a. Bithionol
b. Metrifonate
c. Oxamniquine
d. Praziquantel

c. Urinary schistosomiasis

Metrifonate is used as an alternate drug for:

a. Liver fluke infection
b. Lung fluke infection
c. Urinary schistosomiasis
d. Intestinal schistosomiasis

b. Niclosamide

MOA: Inhibits oxidative phosphorylation.

a. Praziquantel
b. Niclosamide
c. Bithionol
d. Oxamniquine

• Malaria

• Amoebiasis

• Giardiasis

• Trichomoniasis

• Toxoplasmosis

• Pneumocystis carinii pneumonia.

Protozoal infections include:

b. Antimalarials

Common structural feature of _______ is a quinoline ring, or a quinoline with an additional benzene added (acridine ring).

a. Antibacterials
b. Antimalarials
c. Anthelmintics
d. Antifungals

c. Cinchona alkaloids

All antimalarials contain a quinoline ring or acridine ring, except which class that contains a quinuclidine ring?

a. 4-Aminoquinolines
b. 8-Aminoquinolines
c. Cinchona alkaloids
d. Artemisinin derivatives

a. Cinchona alkaloid

Quinine is a _____

a. Cinchona alkaloid
b. 4-Aminoquinoline
c. 8-Aminoquinoline
d. Artemisinin derivative

c. Quinine

Cinchona alkaloid reserved for malarial strains resistant to other agents.

a. Quinidine
b. Mefloquine
c. Quinine
d. Chloroquine

c. Both a and b

• Cinchonism

• Abortifacient properties

Side effects of Quinine include:

a. Cinchonism

b. Abortifacient properties

c. Both a and b

b. Quinine

Cinchonism and abortifacient properties are side effect associated with which antimalarial?

a. Mefloquine
b. Quinine
c. Primaquine
d. Pyrimethamine

c. Chloroquine

7-chloro-4-aminoquinoline.

a. Quinine

b. Mefloquine

c. Chloroquine

d. Primaquine

b. Chloroquine

Drug of choice (DOC) for erythrocytic Plasmodium falciparum for prophylaxis and treatment.

a. Quinine

b. Chloroquine

c. Pyrimethamine

d. Artesunate

b. Chloroquine

Used for acute Plasmodium vivax attack.

a. Primaquine
b. Mefloquine
c. Chloroquine
d. Doxycycline

b. Chloroquine

Has anti-inflammatory properties used for rheumatoid arthritis (RA) and discoid lupus.

a. Hydroxychloroquine
b. Chloroquine
c. Quinacrine
d. Both a and b

c. Amodiaquine

7-chloro-4-aminoquinoline.

a. Chloroquine
b. Hydroxychloroquine
c. Amodiaquine
d. Quinine

b. Amodiaquine

Highly suppressive against Plasmodium vivax and Plasmodium falciparum

a. Mefloquine
b. Amodiaquine
c. Primaquine
d. Pyrimethamine

b. Amodiaquine

Curative for P. falciparum and used for prophylaxis.

a. Mefloquine
b. Amodiaquine
c. Primaquine
d. Pyrimethamine

d. All of the above

• Prophylaxis of P. falciparum

• Curative for P. falciparum

• Suppressive for P. vivax

Amodiaquine is used for which of the following?

a. Prophylaxis of P. falciparum
b. Curative for P. falciparum
c. Suppressive for P. vivax
d. All of the above

c. Primaquine

8-aminoquinoline.

a. Chloroquine
b. Amodiaquine
c. Primaquine
d. Quinine

c. Primaquine

Only effective against the exoerythrocytic stages of malaria.

a. Mefloquine
b. Chloroquine
c. Primaquine
d. Pyrimethamine

b. Primaquine

Used for the radical cure of Plasmodium vivax and Plasmodium ovale.

a. Quinine
b. Primaquine
c. Artesunate
d. Doxycycline

c. Primaquine

Gametocidal for all malaria species.

a. Chloroquine
b. Amodiaquine
c. Primaquine
d. Hydroxychloroquine

b. Quinacrine

9-aminoacridine.

a. Chloroquine
b. Quinacrine
c. Mefloquine
d. Primaquine

b. Quinacrine

Used for giardiasis, leishmaniasis, and tapeworm infections.

a. Chloroquine
b. Quinacrine
c. Pyrimethamine
d. Artemether

c. Quinacrine

Contraindicated with primaquine due to increased toxicity.

a. Quinine
b. Amodiaquine
c. Quinacrine
d. Hydroxychloroquine

c. Mefloquine

4-aminoquinoline

a. Chloroquine
b. Amodiaquine
c. Mefloquine
d. Quinine

c. Mefloquine

Used a Schizonticide

a. Chloroquine
b. Amodiaquine
c. Mefloquine
d. Quinine

c. Mefloquine

For multi-drug resistant forms of Plasmodium falciparum

a. Chloroquine
b. Amodiaquine
c. Mefloquine
d. Quinine

c. Mefloquine

DOC for malarial suppression

a. Chloroquine
b. Amodiaquine
c. Mefloquine
d. Quinine

c. Cycloguanil

Active against both erythrocytic and exoerythrocytic stages of malaria.

a. Chloroquine

b. Mefloquine

c. Cycloguanil

d. Primaquine

d. All of the above

• Emetine

• Dehydroemetine

• Metronidazole

Amebicides that are effective against both intestinal and extraintestinal forms of the disease.

a. Emetine
b. Dehydroemetine
c. Metronidazole
d. All of the above

b. Emetine and Dehydroemetine

Alkaloids derived from Ipecac.

a. Chloroquine and Primaquine
b. Emetine and Dehydroemetine
c. Quinine and Quinidine
d. Artemether and Artesunate

c. Emetine and Dehydroemetine

MOA: Inhibits protein synthesis by preventing protein elongation (protoplasmic poison).

a. Metronidazole
b. Chloroquine
c. Emetine and Dehydroemetine
d. Iodoquinol

b. Emetine and Dehydroemetine

Also used for balantidial dysentery, fascioliasis, and paragonimiasis.

a. Tinidazole
b. Emetine and Dehydroemetine
c. Diloxanide furoate
d. Paromomycin

c. Emetine and Dehydroemetine

Has limited use due to toxic effects on the gastrointestinal tract, cardiovascular system, and neuromuscular system.

a. Metronidazole
b. Chloroquine
c. Emetine and Dehydroemetine
d. Mefloquine

b. Metronidazole

Flagyl®

a. Tinidazole
b. Metronidazole
c. Secnidazole
d. Ornidazole

b. Metronidazole

Protostat®

a. Tinidazole
b. Metronidazole
c. Secnidazole
d. Ornidazole

c. Metronidazole

MOA involves covalent binding of a reactive intermediate from the reduction of the 5-nitro group to DNA, resulting in a lethal effect.

a. Chloroquine
b. Iodoquinol
c. Metronidazole
d. Paromomycin

b. Metronidazole

Used for the treatment of amoebiasis, giardiasis, trichomoniasis, and anaerobic bacterial infections.

a. Diloxanide furoate
b. Metronidazole
c. Emetine
d. Dehydroemetine

a. Disulfiram-like effect

Side effect of Metronidazole is a ______ when taken with alcohol.

a. Disulfiram-like effect
b. Antabuse reaction
c. Flushing syndrome
d. All of the above

b. Alcohol

Side effect of Metronidazole is a disulfiram-like effect when taken with _____

a. Food

b. Alcohol

c. Caffeine

d. Grapefruit juice

d. All of the above

• 8-hydroxyquinoline

• Iodoquinol

• Diloxanide

Amebicides that are effective only against the intestinal forms of the disease.

a. 8-hydroxyquinoline

b. Iodoquinol

c. Diloxanide

d. All of the above

b. 8-Hydroxyquinoline

MOA involves chelation of metal ions.

a. Iodoquinol
b. 8-Hydroxyquinoline
c. Diloxanide
d. Metronidazole

c. Iodoquinol

Derivative of 8-hydroxyquinoline

a. Chloroquine
b. Diloxanide
c. Iodoquinol
d. Paromomycin

c. Iodoquinol

Derivative of 8-hydroxyquinoline used for acute and chronic intestinal amoebiasis.

a. Chloroquine
b. Diloxanide
c. Iodoquinol
d. Paromomycin

d. Diloxanide

Used for the treatment of asymptomatic carriers of Entamoeba histolytica.

a. Metronidazole
b. Tinidazole
c. Iodoquinol
d. Diloxanide

d. Diloxanide

From the discovery of α-dichloroacetamides

a. Metronidazole
b. Tinidazole
c. Iodoquinol
d. Diloxanide

b. α-Dichloroacetamides

Diloxanide was discovered from:

a. Plant alkaloids
b. α-Dichloroacetamides
c. Quinoline derivatives
d. Nitroimidazoles

b. Cotrimoxazole

Sulfamethoxazole + Trimethoprim.

a. Co-trimazine
b. Cotrimoxazole
c. Sulfatrim
d. Bactrim

b. Cotrimoxazole

Drug of choice (DOC) for Pneumocystis carinii pneumonia (PCP).

a. Pentamidine

b. Cotrimoxazole

c. Dapsone

d. Atovaquone

b. Pentamidine isethionate

Used for prophylaxis of African trypanosomiasis

a. Atovaquone
b. Pentamidine isethionate
c. Melarsoprol
d. Suramin

b. Pentamidine isethionate

Rapidly distributed and stored in tissues.

a. Atovaquone
b. Pentamidine isethionate
c. Melarsoprol
d. Suramin

b. Atovaquone

Analog of ubiquinone

a. Pentamidine
b. Atovaquone
c. Proguanil
d. Pyrimethamine

a. Ubiquinone

A component of the mitochondrial electron transport chain (ETC).

a. Ubiquinone

b. Cytochrome c

c. NADH dehydrogenase

d. ATP synthase

c. Atovaquone

MOA interferes with the electron transport chain (ETC) as an antimetabolite for ubiquinone.

a. Trimethoprim

b. Sulfadoxine

c. Atovaquone

d. Primaquine

c. Benzimidazole

Treatment of Chaga's disease (American trypanosomiasis).

a. Suramin

b. Pentamidine

c. Benzimidazole

d. Melarsoprol

c. Suramin

Bisurea derivative containing 6 sulfonic acid groups.

a. Pentamidine

b. Benzimidazole

c. Suramin

d. Nifurtimox

d. Suramin

Used as a long-term prophylactic agent for trypanosomiasis due to high protein binding; effect can last up to 3 months.

a. Benzimidazole
b. Pentamidine
c. Melarsoprol
d. Suramin

c. 3 months

Suramin effect can last up to _____

a. 1 month
b. 2 months
c. 3 months
d. 6 months

c. Melarsoprol

Drug of choice (DOC) for later stages of both forms of African trypanosomiasis.

a. Suramin

b. Pentamidine

c. Melarsoprol

d. Eflornithine

d. Eflornithine

MOA involves irreversible inactivation of ornithine decarboxylase.

a. Suramin

b. Melarsoprol

c. Benzimidazole

d. Eflornithine

b. Eflornithine

Treatment of African sleeping sickness

a. Pentamidine
b. Eflornithine
c. Suramin
d. Nifurtimox

b. Eflornithine

Causes myelosuppression as a side effect.

a. Pentamidine
b. Eflornithine
c. Suramin
d. Nifurtimox

c. Myelosuppression

Eflornithine causes ______ as a side effect.

a. Hepatotoxicity
b. Nephrotoxicity
c. Myelosuppression
d. Cardiotoxicity

d. Nifurtimox

Treatment of Southern American Trypanosomiasis (T. cruzi)
a. Pentamidine
b. Eflornithine
c. Suramin
d. Nifurtimox

b. Trypanosoma brucei gambiense and Trypanosoma brucei rhodesiense

African Trypanosomiasis (Sleeping sickness) is caused by:

a. Trypanosoma cruzi
b. Trypanosoma brucei gambiense and Trypanosoma brucei rhodesiense
c. Leishmania donovani
d. Plasmodium falciparum

b. Trypanosoma cruzi

American Trypanosomiasis (Chaga's disease) is caused by:

a. Trypanosoma brucei gambiense
b. Trypanosoma cruzi
c. Trypanosoma brucei rhodesiense
d. Leishmania braziliensis