Lecture 3: Treatment for GI Infections

Question 1

What are the three treatment options for Clostridium difficle and when are they used?

Answer 1

• Vancomycin (ORAL ONLY) or Metronidazole if vancomycin is not available or cannot be used
• Fidaxomicin should be used for 1st recurrence of C. difficle

Question 2

What antibiotics are Vancomycin, Ciprofloxacin, Fidaxomicin, and Azithromycin?

Answer 2

V - glycopeptide
C - fluoroquinolone
F/A - macrolide

Question 3

What are the two treatment options for Campylobacter jejuni, Salmonella species, and Shigella species?

Answer 3

Ciprofloxacin (FIRST CHOICE) or Azithromycin

Question 4

What are the 7 Anthelmintic drugs available? (A/M/T and I/N/P/PP)

Answer 4

Benzimidazoles

• Albendazole, Mebendazole, Thiabendazole (SKIN)
• Thiabendazole has tissue toxicity –> use on skin

Misc
- ivermectin, nitazoxanide, praziquantel, pyrantel pamoate

Question 5

What are the two MOAs of Benzimidazoles? (B/FR)

Answer 5

1. inhibit microtubule polymerization (beta tubulin bind)
   
   • dec. glucose transport
2. inhibit mitochondrial fumarate reductase
   
   • immobilization and death

Question 6

What is the MOA of Ivermectin?

What infection is it typically used for and with what?

Answer 6

• binds selectively to glutamate-gated Cl ion channels
• causes hyperpolarization –> tonic paralysis of worms nerves and muscles

use for Strongyloides stercoralis (w/abendazole for lymphatic filariasis)

Question 7

What is the MOA of Nitazoxanide?

Answer 7

• interferes with pyruvate:ferredoxin oxidoreductase (PFOR) electron transfer reaction
• essential for anaerobic energy metabolism

Question 8

What are the two MOAs of Praziquantel?

Answer 8

1. inc. cell membrane permeability = paralysis of musculature
2. disintegration of shistosome tegument followed by phagocyte attachment = death

Question 9

What are the two MOAs of Pyrantel Pamoate?

Answer 9

1. depolarizing neuromuscular blocker that induces persistent activation of nicotinic acetylcholine receptors
2. inhibits cholinesterases = spastic paralysis

Question 10

What are three GI focused anti-protozoal drugs? (P/M/T)

What are their MOAs?

Answer 10

paromomycin
- aminoglycosides (30s subunit)

metronidazole, tinidazole

• creates nitro-radicals that disrupt organism DNA
• believed to be a PRO-drug

Question 11

What two drugs would you use to treat Entamoeba histolytica?

Answer 11

DUAL THERAPY –> pick the option with both of these

Metronidazole followed by Paromomycin

Question 12

What two drugs would you use to treat HOOKWORMS, such as Ancylostroma species and Necator americanus?

Answer 12

Albendazole (or Mebendazole if first choice not available)

Question 13

What two drugs would you use to treat ROUNDWORM Ascaris lumbricoides?

Answer 13

Albendazole (or Mebendazole if first choice not available)

Question 14

What two drugs would you use to treat Giardia species?

Answer 14

Albendazole (or Mebendazole if first choice not available)

Question 15

What drug would you use to treat ADULT forms of TAPEWORM, such as Diphyllobothrium latum and Taenia species (except CYSTERICERCOSIS specific)?

Answer 15

Praziquantel

Question 16

What drugs would you use to treat LARVAL forms of TAPEWORM, specifically:

1. Echinoccus granulosus
2. Taenia solium (Cysticercosis-specific)

Answer 16

1. Albendazole + Praziquantel (DUAL THERAPY)

2. Albendazole

Question 17

What drug would you use to treat:

1. Enterobius vermicularis (PINWORM)
2. Schistomsoma species
3. Strongyloides stercoralis
4. Trichuris trichiura
5. Trichinellosis species

Answer 17

1. Mebendazole (Albendazole if first choice not available)
2. Praziquantel (+ steroids for neurological disease)
3. Ivermectin
4. Mebendazole (Albendazole if first choice not available)
5. Albendazole (Mebendazole) + steroids for severe disease

Question 18

What drugs would you use to treat:

1. Crytosporidium species
2. Cyclospora cayetanesis

Answer 18

1. Nitazoxanide
2. Trimethoprim-Sulfamethoxazole (TMP-SMZ)
   • use CIPROFLOXACIN for sulfa-allergic patients