C3. Antiprotozoal and antihelminthic drugs. Flashcards
List the drugs for P. Jiroveci infection(fungi).
- Cotrimoxazole (TMP-SMX)
- Pentamide + Sulfadiazine + folic acid
- Pentamide (?)
- Primaquine + Clindamycin
- Atovaquon
List the Antimalarials.
- Chloroquine
- Quinidine (+ doxycycline/clindamycin)
- Quinine
- Mefloquine (+/- artesunat)
- Primaquine
- Halofantrine
- Sulfadoxine + pyrimethamine
- Atovaquone
- Proquanil
- Artemisinin
- Malaron (proguanil + atovaquone)
- Lumefantrine (+arthemeter)
- Artesunat (+meflo/doxy/clinda)
- Artemotil
- Dihydroartemisinin
- Doxycycline (+-quinine /artesunat)
- Clindamycin (+ quinine /artesunat)
- Azithromycin
List the drugs used for Giardiasis:
- Metronidazole (Nitromidazole)
- Tinidazole
- Nitazoxanide
- Paromomycin
- Furazolidon
- Quinacrin
List the drugs for Toxoplasmosis?
- Pyrimethamine + Sulfadiazine
- Pyrimethamine + Clindamycin
- Spiramycin
- Cotrimoxazole (tmp/smx)
- (folinic acid)
List the drugs used in Trichomoniasis.
- Metronidazole (Nitroimidazole)
- Tinidazole
List the drugs used in Leishmaniasis.
- Amphotericin B
- Miltefosine
- Sodium Stibogluconate
- Meglumin
- Antimoniat
- Pentamidine (Pentavalent antimonials)
List the Amebiasis treatment.
- Iodoquinol
- Diloxanid furoat
- Paromomycin
- Metronidazole (+Tinidazole)
- Tinidazole
List the agents used in Trypanosomiasis.
African trypanosomiasis: (T. Brucei)
- Eflornithin
- Melarsoprol
- Pentamidine
- Suramin
American trypanosomiasis: (T. cruzi)
- Nifurtimox
- Benznidazole
List the Antihelminthic agents.
Benzimidazoles:
- Albendazole
- Mebendazole
- Triclabendazole (Levamisole)
Others:
- Diethylcarbamazine (DEC)
- Ivermectin
- Pyrantel Pamoate
- Praziquantel
- Niclosamide
- Biothionol
What is the MOA of Chloroquine?
MOA: inhibits heme polymerase → heme accumulates and is toxic to blood schizonts
How are Anti-Malarials classified?
Medications can be classified according to their efficacy on certain life-cycle stages:
- Tissue Schizonticides - act on liver forms; includes primaquine
- Blood Schizonticides - act on erythrocyte forms + prevent clinical symptoms; includes chloroquine, quinine
- Gametocides - kill gametocytes; includes primaquine
- Prophylactics
What is the MOA of Quinine and Quinidine?
They are cinchona alkaloids acting on blood schizonts by unknown mech (gametes in P. vivax/ovale).
What is the MOA of Mefloquine?
It has a unknown mechanism against blood schizonts + P. vivax/ovale gametes.
What is the MOA of Bithionol?
Bithionol inhibits oxidative phosphorylation.
What is the MOA of Pyrantel Pamoate?
Pyrantel Pamoate causes ACh release and ACh-ase inhibition → spastic paralysis.
What is the MOA of Niclosamide?
Niclosamide inhibits oxidative phosphorylation.
What is the MOA of Praziquantel?
Praziquantel increases calcium permeability → spastic paralysis.
What is the MOA of Levamisole?
Levamisole causes depolarizing neuromuscular blockade → paralysis.
What is the MOA of Ivermectin?
Ivermectin enhances GABA effect in helminths → paralysis.
What is the MOA of the Benzimidazoles?
Albendazole, mebendazole and thiabendazole inhibit B-tubulin polymerization → paralysis.
List the classifications of Helminths.
Classified into:
- Nematodes (roundworms)
- Trematodes (flukes)
- Cestodes (tapeworms)
What is the MOA of Nifurtimox?
Nifurtimox has an unclear mechanism; maybe radical metabolites effective in acute phase.
What is the MOA of Eflornithine?
Eflornithine inhibits ornithine decarboxylase.
What is the MOA of Sulfadoxine and pyrimethamine?
They inhibit folate synthesis.
Which drugs are used in the visceral form of leishmaniasis?
Amphotericin B or Miltefosine (oral)
List the 1st line drugs in Toxoplasmosis.
1st line = spiramycin, TMP-SMX or pyrimethamine + clindamycin + folinic acid (↓ sfx)
What is given in Trichomoniasis?
Nitroimidazoles, such as metronidazole.
What is the first line treatment of Giardiasis?
Nitroimidazoles + Nitazoxanide
What is the MOA for Iodoquinol?
Iodoquinol has an unknown mechanism. Perhaps because it has a poor oral absorption → luminal effect.
What is the MOA of Primaquine
Primaquine has an unknown mechanism against tissue schizonts in all strains.
What is the MOA of Halofantrine ?
Halofantrine has an unknown mechanism against blood schizonts in all strains.
What is the route of administration of Halofantrine?
Given orally + absorption enhanced by food.
What are the side effects of Halofantrine?
Side Effects:
- GI, rash, pruritus
- Arrhythmia - causes conduction disturbances (rarely used b/c of this … Lumefantrine has fewer side effects and is given with artemether for uncomplicated P. falciparum)
What is the pharmacokinetics like for Primaquine?
oral admin with good absorption
What are the indications of primaquine?
- Acute vivax or ovale malaria - curative
- prophylaxis for all strains P. jirovecii - with clindamycin
what are the side effects of primaquine?
well-tolerated, but:
- GI effects in high doses
- Rarely leukocytopenia, methemoglobinemia and HS reactions.
What is the MOA of Benznidazole?
Benznidazole inhibits protein + RNA synthesis.
What is the MOA of Melarsoprol?
Melarsoprol contains arsenic and thereby inhibits enzymes. Given as slow infusion.
When is pentamidine given in trypanosomiasis?
Pentamidine is given in early phase before CNS involvement.
What is the MOA and DOA of Suramin?
Suramin is also used in early phase trypanosomiasis. Unclear mechanism; inhibits protein synth + enzymes. Given IV and has a long half-life (40-50 days).
What is the MOA of Atovaquone?
Atovaquone inhibits mitochondria, affecting tissue + blood schizonts.
What is the MOA of Artemisinin?
Artemisinin and derivatives artemether, artemotil, artesunate, dihydroartemisinin may act through free radical production against blood schizonts.
What is the MOA of Proguanil?
Proguanil is given with atovaquone. It is a biguanid derivative with an active metabolite that inhibits 2HF reductase thymidylate synthase → ↓ DNA synthesis.
What are the kinetics like for Chloroquine?
Given orally, accumulates in tissues, half life = 4 days.
What are the indications for chloroquine?
For suppression and prophylaxis P. falciparum is often resistant!
What are the side effects of chloroquine?
Chloroquines are well tolerated, however some side effects can occur like:
- Pruritus and GI effects
- Visual disturbances - rare, due to retinal/corneal deposits
- Hemolysis - in G6PD deficiency
What is the route of administration of quinine and quinidine?
Both are given orally and can be given by slow IV.
What are the side effects of quinine and quinidine?
- Cinchonism - quinine intoxication
- GI symptoms: Vomitting/Diarrhea
- Visual/hearing disturbance
- HS rxn
- Overdose can cause cardiotoxicity
What are the kinetics like for Mefloquine?
Orally administered with slow absorption.
What are the side effects of Mefloquine?
GI and neuropsychiatric effects
What are the indications for Mefloquine?
- Prophylaxis - if chloroquine resistant P. falciparum (use ↓ due to side effects).
- Uncomplicated Malaria - with artesunate.
What are the kinetics like for Bithionol?
Orally admin with BBB penetration.
What are the side effects of Biothionol?
- GI
- CNS (dizziness, HA)
- toxic hepatitis
What are the indications of biothionol?
In fascioliasis (Fasciola hepatica)
What are the kinetics like for pyrantel pamoate?
Orally admin with poor absorption
What are the side effects like for pyrantel pamoate?
- GI (medium severity)
- mild CNS effects
What are the indications like for pyrantel pamoate?
Various roundworms (Ascaris, Necator, Ancylostoma, and Enterobius)
What is the route of administration of Niclosamide?
orally admin with poor absorption
What is the route of administration of Praziquantel?
oral admin and crosses BBB
What is the route of administration of Levamisole?
orally administered.
What are the kinetics like for ivermectin?
Orally admin; does not cross BBB.
What are the indications for Benzimidazoles?
roundworm and tapeworm infections
List the drugs targets of Antihelminthic drugs.
Drug targets are:
1) Neuromuscular coordination
2) Carbohydrate metabolism
3) Microtubules
What is the route of administration of Eflornithine?
Given as IV (oral → diarrhea)
What is the route of administration and side effects of Nifurtimox?
- Given orally
- Causes GI effects, neuropathy, seizures
What are the indications of sulfadoxine and Pyrimethamine?
For chloroquine resistant uncomplicated malaria (falciparum often resistant!)
List the 2nd line drugs in toxoplasmosis.
2nd line = pyrimethamine + sulfadiazine + folinic acid
What is the second line therapy for giardiasis?
- Paromomycin, or…
- Furazolidone - a nitrofuran, given orally with GI side effects
- Quinacrine - broad-spectrum anti-protozoal; oral, long half-life, GI sfx
What are the side effects of melarsoprol?
- GI effects
- hepatotoxic
- arrhythmia
- encephalopathy (give in severe CNS cases)
What is the MOA of Nitroimidazoles?
Metronidazole and tinidazole have reactive reduction products that are cytotoxic.
What are the indications for the Nitroimidazoles?
Given in combination for intestinal/extraintestinal infection (amebiasis)
What is the MOA of Paromomycin?
Paromomycin is a protein synthesis inhibitor (aminoglycoside) used as a 2nd line for extra-/intestinal amebiasis.
What are the side effects of Iodoquinol?
GI upset
What are the indications for Iodoquinol?
- Asymptomatic intestinal amebiasis - as a monotherapy
- Intestinal / extraintestinal amebiasis - in combination
What is the MOA of Diloxanide Furoate?
Diloxanide Furoate has an unknown mechanism. Perhaps it is its metabolite diloxanide that is absorbed that has some effect. (?)
What are the side effects of Diloxanide Furoate?
GI upset
What are the indications of Diloxanide Furoate?
It’s an alternative for asymptomatic amebiasis.
What is the route of administration of Benznidazole?
oral admin
What are the side effects of Benznidazole?
- GI effects
- neuropathy
- psychosis
What are the side effects of Suramin?
- Kidney impairment
- Dermatitis
- Neuropathy
What are the indications of atovaquone?
- Given with proguanil as treatment/prophylaxis in chloroquine-resistant strains (falciparum usually sensitive!)
- P. jirovecii - alternative treatment for infection.
What is the route of administration of Artemisinin?
Artemisinin can be given oral, IV or IM
What are the side effects of Artemisinin?
Artemisinin is well-tolerated however there are some GI effects.
What are the indications of Artemisinin?
Given in combination for uncomplicated malaria (w/ mefloquine or lumefantrine)
What are the side effects of Niclosamide?
GI, dizziness
What are the indications for Niclosamide?
Taenia species (solium and saginata)
What are the side effects of praziquantel?
GI, dizziness
What are the indications for Praziquantel?
Against flukes and tapeworms (Schistosoma, F. hepatica, and Taenia)
What are the side effects of Levamisole?
- GI
- Mild neurological symptoms
What are the indications for Levamisole?
Certain roundworms (A. lumbricoides, A. duodenale, and N. americanus)
What are the side effects of Ivermectin?
Mild, due to worm disintegration (fever, HA, dizziness, itching, joint pain).
What are the indications of Ivermectin?
Certain roundworms (Loa loa, A. lumbricoides, A. duodenale and T. trichiura)
What is the route of administration for Benzimidazoles?
Oral administration
What are the side effects of Benzimidazoles?
- GI
- Hepatotoxic
- Visual disturbances
- Teratogenic
What are the side effects of Eflornithine?
GI effects, seizures and marrow suppression (give in severe CNS cases)
What is the 1st line therapy for P. jiroveci infection?
1st line = TMP-SMX
What is the route of administration of Pentavalent antimonials?
Pentavalent antimonials such as sodium stibogluconate or meglumine antimoniate given IV as first choice in mucocutaneous form; few side effects
What is the 2nd line therapy for P.jiroveci therapy?
2nd line = pentamidine or clindamycin plus primaquine or atovaquone
What is the MOA of Pentamidine?
Pentamidine is reserve compound for antimonial resistance, which also has fungicidal effect. It has an unclear MOA. May inhibit DHFR or protein synthesis.
What is the route of administration of Pentamidine?
given parenterally
What are the side effects of Pentamidine?
- Arrhythmia
- Liver / Kidney disturbance
- Stevens-Johnson Syndrome