04a: Pharmacology Flashcards
1
Q
“-tidine” drugs
A
H2 R blockers
2
Q
“-prazole” drugs
A
PPIs
3
Q
List the 3 major substances that stimulate H secretion from parietal cells.
A
- Histamine (paracrine) from ECL cells
- Gastrin (endocrine) from G cells
- ACh (neural) from enteric nerves
4
Q
T/F: Both PPIs and H2 antagonists are taken in the morning, before breakfast, for max effect.
A
False - H2 antagonists taken once daily at bedtime (inhibit nocturnal acid secretion)
5
Q
(PPIs/H2 antagonists) are administered as prodrug with enteric coating for absorption/release in (X).
A
PPIs;
X = duodenum
6
Q
T/F: PPIs have slow onset and long duration of action.
A
True
7
Q
T/F: PPIs have long elimination half-life.
A
False
8
Q
T/F: Both PPIs and H2 antagonists used in ZES.
A
False - PPIs
9
Q
(Ranitidine/Odansetron/Omeprazole) dose should be adjusted for low CYP2C19 metabolizers.
A
Omeprazole
10
Q
Patient with chronic pain and on chronic NSAIDs presents with GI toxicity. What are Rx options?
A
- Switch to COX-2 selective inhibitor
- Add PPI to drug regimen
- Add prostaglandin analogue (misoprostol) to drug regimen
11
Q
List risk of long-term PPI use.
A
- C. diff diarrhea
2. Hip fracture (esp post-menopausal F smokers)
12
Q
Prototypic antacids include which salts?
A
Mg(OH)2 and Al(OH)3
13
Q
Side effects of antacids:
A
- Constipation (Al) or diarrhea (Mg)
- Systemic alkalosis
- Excess cation absorption (Na, Ca)
14
Q
The emetic center, located in (X), receives inputs from:
A
X = medulla
- Area postrema
- Tractus solitarius
- Cerebellum
- Higher centers
15
Q
Blood-borne cytotoxic drugs and gut bacteria can both cause emesis via (X) pathway to the emetic center.
A
X = small intestine to vagal/sympathetic efferents to area postrema OR solitary tract
Note: blood-borne emetics can also affect area postrema directly
16
Q
Which four main receptors have been targeted for (activation/inhibition) by anti-emetics?
A
Inhibition (antagonists to:)
D2, M, 5HT3, H1
17
Q
Odensetron is what kind of drug?
A
Anti-emetic; 5-HT3 (serotonin) R antagonist
18
Q
T/F: Glucocorticoids can be used as anti-emetic agents.
A
True
19
Q
Cannabinoid-R (agonists/antagonists) and Substance P (agoinsts/antagonists) can be used as anti-emetic agents.
A
Agonists; antagonists
20
Q
T/F: Studies have shown that anti-emetics are equally as effective in mono and combo therapies.
A
False - more effective in combo
21
Q
List some therapeutic uses for laxatives and cathartics.
A
- Counteract opioid constipation
- Management of chronic constipation in elderly
- Prior to colonoscopy
22
Q
Methylcellulose is a(n) (X) agent that has which MOA?
A
X = bulk-forming laxative
High content of indigestibles (cellulose or its derivatives) soften the stool by increasing the fecal water content and stimulate peristaltic activity
23
Q
List examples of osmotic cathartics.
A
- Mg and phosphate salts
2. Polyethylene glycol
24
Q
Docusate is example of which drug?
A
“Stool softeners”, aka emollient laxatives
25
Bisacodyl is example of which drug?
Stimulant cathartic
26
Patient planning to undergo colonoscopy for screening purposes is given (Methylcellulose/Docusate/Polyethylene glycol/Bisacodyl), which has a (slow/fast) onset of action.
Polyethylene glycol (osmotic cathartic)
Fast (few hours)
27
T/F: Naltrexone is effective against opioid-induced constipation.
True - but not used for this purpose due to its inhibition of opioid CNS effects as well
28
(X) drug is used to counteract opioid-induced constipation due to its (tertiary/quaternary) ammonium and selectivity to the periphery.
X = methylnaltrexone
| Quaternary (limited access into CNS)
29
T/F: Opioid agonists are used as OTC anti-diarrheal drugs.
True (but those with limited CNS distribution)
30
Loperamide, aka (X), is what type of drug?
X = imodium
Anti-diarrhetic (opioid agonist)
31
Patient with diarrhea should not be given opioids for Rx if he/she presents with:
bloody diarrhea (opioids ay prolong infections with invasive bacteria like shigella)
32
What are the general drug class options for diarrhea in IBD?
1. 5-ASA (5-aminosalicylates)
2. Corticosteroids
3. Anti-metabolites (azathioprine)
4. Biologics
33
Mesalamine is in (X) class of drugs, used to treat (diarrhea/constipation) caused by (Y).
X = 5-ASA
Diarrhea
Y = IBD
34
List two TNF-alpha (agonsts/antagonists) used to treat diarrhea in IBD.
Antagonists;
1. Infliximab (mouse/human IgG1)
2. Adalimumab (fully humanized IgG1)
35
(X) is an Integrin alpha-4 (agonist/antagonist) used to treat (constipation/diarrhea) caused by (Y).
X = Vedolizumab
Antagonist
Diarrhea;
Y = IBD (moderate/severe Crohn's/UC that's unresponsive to other Rx)
36
Vedolizumab MOA:
Blocks lymphocyte interaction with adhesion molecules (MAdCAM-1) on vascular endothelium in inflamed regions of intestine
37
Patient with IBD and on (X) drug is at risk of (Y)-virus associated progressive multifocal leukoencephalopathy (PML).
```
X = Vedolizumab
Y = JC
```
38
Intestinal ischemia can be the result of (arterial/venous) obstruction, such as:
Either
Embolus (arterial), thrombus (arterial or venous)
39
Aside of obstruction, intestinal ischemia can be the result of:
Decreased blood flow
40
List the mechanisms of intrinsic blood flow regulation to the intestines.
1. Sympathetic fibers (splanchnic nerves)
| 2. NE (artery/arteriole constriction)
41
Digitalis glycosides have which effect on intestinal blood flow?
Vasoconstrictive (decrease flow)
42
Following several hours of intestinal ischemia, (X) causes (vasodilation/vasoconstriction) and (increase/decrease) in collateral blood flow.
X = hypoxemia
Vasoconstriction
Decrease
43
T/F: Hypoxemia-induced vasoconstriction of splanchnic circulation can be reversed once ischemia has been corrected.
False - if vasoconstriction is sustained for a long enough period of time, it will persist despite return of blood flow to the area
44
Intestinal ischemia: cell death occurs in lumen (first/last) and spreads to which layers?
First;
| Spreads outward from lumen until there is total transmural necrosis
45
List the three categories of intestinal ischemia. How often is each the cause of ischemia?
1. Colonic ischemia (60%)
2. Acute mesenteric ischemia (30%)
3. Chronic mesenteric ischemia (5%)
46
You would have high suspicion of AMI in patient that presents with which clinical findings?
1. SUDDEN onset abdominal pain (may be post-prandial)
| 2. Pain out of proportion to the exam (can't palpate abdomen due to intense pain)
47
List the top four most common etiologies of AMI.
1. SMA Embolus (50%)
2. NOMI (Non-occlusive; 25%)
3. SMA Thrombosis (10%)
4. Mesenteric venous thrombosis (10%)
48
AMI: Emboli that have passed into (X) artery are no longer (minor/major), but (minor/major) emboli.
X = ileocolic
Major
Minor
49
T/F: About 1/5 of patients presenting with AMI will have peripheral emboli.
True
50
(X) cause of AMI is similar to ACS (Acute coronary syndrome) in that the (embolus/thrombus) forms atop a(n) (Y).
X = SMA thrombosis
Thrombus
Y = plaque
51
Patient with hx of stroke and peripheral vascular disease is at risk for which AMI etiology?
SMA thrombosis
52
Patient with CHF (HFrEF) presents with sudden confusion and abdominal distension; you worry the cause is AMI. Which etiology may be likely in this patient? Explain.
NOMI (non-occlusive);
Poor CO and hypoperfusion causes ischemia and persistent/irreversible vasoconstriction
53
The "string of sausages" sign on SMA angiogram is classic finding in which disease?
NOMI
54
(X) cause of AMI is seen in younger patients with (Y) deficiencies.
X = mesenteric venous thrombosis
Hypercoaguable states
Y = Protein C/S, antithrombin III
55
(X) cause of AMI is commonly superimposed on chronic mesenteric ischemia, so up to half of these patients will report a history of which symptom?
X = SMA thrombosis
Post-prandial intestinal angina (weeks/months preceding acute event)
56
AMI: upon admission, about (X)% of patients have a
| (leukopenia/leukocytosis) and about (Y)% have which acid/base disorder?
```
X = 75
Leukocytosis (above 15,000 cell/mm3)
Y = 50
Metabolic acidosis (GAP)
```
57
Which X-ray findings are consistent with AMI?
Thumb-printing (suggesting submucosal hemorrhage and edema)
58
Gold standard for diagnosis of AMI
Angiogram
59
How might (X) imaging modality be a therapeutic, as well as diagnostic, option for AMI?
X = angiogram
Intra-arterial agents (ex: paparavine - a vasodilator)
60
Initial treatment of AMI.
1. Treat underlying cause (CHF, arrhythmia, blood V)
| 2. Broad-spectrum antibiotics
61
T/F: AMI with infarct has mortality rate as high as 90%.
True
62
T/F: Diagnosis of both occlusive and non-occlusive AMI can be made with angiography.
True
63
Patients with CMI (chronic mesenteric ischemia) are typically (obese/cachectic) with PMHx of which diseases?
Cachectic (develop sitophobia/fear of eating due to post-prandial pain)
CAD, PVD
64
List some clinical and angiography findings that would support diagnosis of CMI (chronic mesenteric ischemia).
1. Unexplained weight loss, abd pain, food aversion
| 2. Occlusion of 2+ splanchnic arteries on angiogram
65
CMI (chronic mesenteric ischemia) therapy.
Revascularization via:
1. Surgery
2. Percutaneous angioplasty/stenting
66
Colonic ischemia: typically (life-threatening/benign) and seen frequently in (younger/older) patients. What are some clinical findings?
Benign; older
Pain (LLQ), urge to defacate, some blood in stool
67
If an acute AKI due to mesenteric venous thrombosis (MVT) is suspected, which test should you order right away?
CT with contrast (diagnoses 90% of patients with MVT)
68
Patient with AMI due to MVT would be treated with (X) unless showing signs of (Y), in which case immediate surgery required.
```
X = heparin (potentially after prompt laparotomy/bowel resection)
Y = infarct
```
69
Nonocclusive colon ischemia tends to occur in which areas of the colon?
Watershed areas, with less collaterals (splenic fixture and rectosigmoidal junction)
70
T/F: Angiogram is gold standard for diagnosis of cholonic ischemia.
False - not typically needed; endoscopy (colonoscopy) is diagnostic
71
Which endoscopy/colonoscopy finding is consistent with colonic ischemia?
"Single stripe sign" - single linear colonic ulcer
72
Natural history of colonic ischemia:
Symptoms subside 24-48h, healing in 2 weeks
| more severe damage may take months
73
Nitazoxamide is active against (protozoa/helminths) and has which mechanism of action?
Both;
Active metabolite interferes with e-transfer reaction (PFOR), which is essential to anaerobic metabolism
74
Metronidazole-resistant protozoa can be treated with (X). Give example of protozoal species that (X) is used for.
X = nitazoxanide
Giardia and Cryptosporidium parvum
75
T/F: Metronidazole has very large Vd.
True
76
(Metronidazole/paromomycin/nitazoxamide) is poorly absorbed and works in GI lumen.
Paromomycin
77
T/F: Nitazoxanide is approved for treatment in adults only.
False - kids too (over 1 y.o.)
78
Praziquantel is Rx for (trematodes/nematodes/cestodes).
Trematodes (flukes) and cestodes (flatworms/tapeworms)
79
Which GI nematodes can be treated with either albendazole or (X)?
X = ivermectin
1. Ascaris lumbricoides
2. Strongyloides stercoralis
80
Which tissue nematodes are treated with albendazole?
1. Trichinella spiralis
| 2. Toxocara canis
81
Which tissue nematodes are treated with diethylcarbamazine?
1. Wuchereria bancrofti
| 2. Loa loa
82
Which tissue nematodes are treated with ivermectin?
Onchocerca volvulus
83
Albendazole is active against helminth (larvae/adults/eggs).
Larvae, adults, and some eggs (Ascaris lumbricoides)
84
Albendazole mechanism of action.
Inhibits MT polymerization (immobilization and death of parasite)
85
T/F: Albendazole oral absorption is decreased if taken with fatty meals.
False - improved
86
T/F: Albendazole is not recommended for pregnancy until after 1st trimester.
False - that's metronidazole; albendazole isn't recommended in pregnancy at all
87
Ivermectin mechanism of action.
Enhances Cl influx through Glu-gated Cl channels, causing hyperpolarization of nerve/muscle cells and paralysis/death of parasite
88
T/F: Ivermectin and diethylcarbamazine are contraindicated in pregnancy.
False - only ivermectin is
89
Ivermecting: (oral/IV), (well/poorly)-absorbed, (small/large) Vd, and (does/doesn't) enter CNS.
Oral; well-absorbed and large Vd but doesn't enter CNS
90
Mazzotti reaction is seen with (X) drug(s) when used against (Y) parasite.
X = ivermectin, diethylcarbamazine
Y = onchocerca volvulus
91
What occurs in the Mazzotti reaction?
Potentially life-threatening allergic response caused by killing microfilaria
92
Diethylcarbamazine mechanism of action.
Immobalizes microfilariae and alters surface structure
93
Praziquantel mechanism of action.
Increases permeability of trematode and cestode cell membranes to Ca (paralysis, dislodgement, death)
94
T/F: Praziquantel is contraindicated in pregnancy.
False - safe in pregnancy
