Pharmacology

Question 1

Psyllium?

Answer 1

• natural plant products that are bulk forming laxatives to treat intermittent IBS constipation
• colloids that absorb water to form a bulky lubricating gel

Question 2

Osmotic laxative MoA?

Answer 2

increase water content of stool for acute constipation and cleanse bowel prior to colonoscopy

Question 3

Magnesium hydroxide?

Answer 3

Nonabsorbable osmotic agent for constipation

-magnesium can be absorbed and cause renal toxicity

Question 4

Loperamide?

Answer 4

OTC opioid agonist

-doesnt cross BBB

Question 5

Diphenoxylate?

Answer 5

Opioid agonist prescription needed

-higher dose can produce CNS effects and lead to opioid dependence

Question 6

Alosetron? ADR?

Answer 6

blocks serotonin receptor 5-HT3 for diarrhea symptoms of IBS in women
-constipation (ischemic colitis)

Question 7

Odansetron?

Answer 7

anti emetic for chemo induced N/V

Question 8

Order of drugs for IBD?

Answer 8

1. 5-aminosalicylic acids (Mesalamine)
2. Corticosteroids for acute flares
   - Prednisone
   - Budesonide
3. Immunosuppressives
   - Azathioprine, Mercaptopurine, Methotrexate (Crohns/UC)
   - Cyclosporine (UC)
4. Anti TNF alpha receptor antagonists
   - Adalimumab
5. Anti-integrein therapy
   - Natalizumab

Question 9

MoA of 5-ASA?

Answer 9

inhibit NF-kB transcription factor to reduce pro inflammatory cytokines

Question 10

Sulfasalazine?

Answer 10

5-ASA

• colonic bacteria break azo bond to release 5-ASA
• do not use if sulfa allergy

Question 11

Mesalamine?

Answer 11

5-ASA

-used more often than sulfasalazine

Question 12

Adalimumab?

Answer 12

TNF alpha antagonist used for Crohn’s and UC

-use if patient has inadequate response to mesalamine or steroids

Question 13

Natalizumab?

Answer 13

Anti-Integrin therapy

• prevents leukocyte binding to vascular endothelium (Ps-selectins and ICAM-1)
• used when crohns patients refractory to TNF alpha antagonist

Question 14

Budesonide?

Answer 14

Newer corticosteroid for UC

-inhibits production of inflammatory cytokines (TNF, IL-1, IL-8) and cell adhesion molecules

Question 15

Treatment for moderate to severe UC?

Answer 15

• Steroids

- Meraptopurine or Azathioprine for steroid or cyclosporine induced remissions

Question 16

Long term treatment for Crohns for refractory cases to conventional therapy?

Answer 16

anti-TNF drugs

Question 17

Metoclopromide?

Answer 17

pro kinetic

Question 18

Is there a vaccine for parasitic infections?

Answer 18

No

-not a problem in the western world where all the industries are

Question 19

Benzimidazole?

Answer 19

• Thiabendazole, Mebendazole, Albendazole
• part of mass deworming program for children
• bind beta tubulin in nematodes and inhibits microtubule assembly
• broad spectrum

Question 20

Benefit of using albendazole for parasitic infections?

Answer 20

single dose

-mass treatment in developing countries

Question 21

Man who works on farm without shoes presents with weakness, nausea, anemia, anorexia, and dark colored stools. Larva is found in sputum.

1. Diagnosis?
2. Treatment?

Answer 21

1. Hookworm

2. Albendazole (single dose)

Question 22

Patient presents with hookworm folliculitis. Treatment?

Answer 22

Topical Thiabendazole

Question 23

Drug of choice for Toxocariasis and Cysticercosis?

Answer 23

Albendazole

-metabolized after absorption and distributed widely in tissues

Question 24

Drug of choice for indwelling GI nematodes (ascariasis)?

Answer 24

Mebendazole
-not well absorbed outside GI

Piperazine (Vermizine)

• paralyzes ascaris by blocking acetylcholine at NMJ
• not indicated for pregnancy

Question 25

Pyrantel Pamoate?

Answer 25

- use for ascariasis and enterobiasis (pinworm) | - constant release of Ach causes persistent parasite nicotinic Ach receptor activation and paralysis

Question 26

Ivermectin?

Answer 26

- single oral dose clears microfilaria from skin - use for onchocerciasis and strongyloides, filariasis, scabies, lice, cutaneous larva migrant - dont use for children or pregnancy

Question 27

Praziquantel?

Answer 27

- use for schistomiasis (mass deworming) | - increases parasite cell membrane permeability

Question 28

Patient with gross hematuria and portal HTN after swimming in Ghana (schistomiasis). Treatment?

Answer 28

PZQ

Question 29

Patient with river blindness (onchocerciasis). Treatment?

Answer 29

Ivermectin

Question 30

Drug for soil transmitted nematodes?

Answer 30

Benzimidazole Use for: - ascaris - trichuris - necator - ancylostoma

Question 31

Pyrethroids (permethrin)?

Answer 31

- derived from Chysanthemum - use for lice and scabies - delays depolarization by impeding Na channel closure - lindane use as 2nd line drug

Question 32

Malathion (ovide)?

Answer 32

- irreversible inhibits Achesterase | - use for lice

Question 33

Dapsone?

Answer 33

-treat leprosy, PCP, toxoplasmosis, leishmaniasis

Question 34

Metronidazole? ADR?

Answer 34

- reacts with DNA to kill organism - use for Trichomonas, H. pylori, C. diff, anaerobes, amebiasis, and giardiasis - 2nd line agent (oral Vancomycin is 1st line) ADR - disulfiram effect (flushing) - peripheral neuropathy - encephalopathy

Question 35

Nitazoxanide use?

Answer 35

Cryptosporidiosis and Giardiasis

Question 36

Furazolidone?

Answer 36

-use for giardiasis ADR - hemolytic anemia in G6PD - contraindicated in neonates and breast feeding

Question 37

Paromomycin?

Answer 37

- aminoglycoside inhibits 30s ribosome | - use for E. histolytica