Pharm2 4 GI Drugs pt2

Question 1

Anticholinergics MoA

What are they used for? (3)

Answer 1

Competitive antagonist at muscarinic acetylcholine (M1) receptors
Used for the prophylaxis and/or treatment of nausea and motion sickness, intestinal cramping

Question 2

What is the antiemetic patch put on behind the ear?

Answer 2

Scoplolamine transdermal

Question 3

Scoplolamine transdermal is indicated for postop N/V, but nobody uses it for this anymore.
How is it used now?

Answer 3

Put it on 12-24 hours before you do the activity that will cause the motion sickness.
Take it off before putting on another, and put the other one behind the other ear.

Question 4

Scoplolamine Transdermal (Transderm Scop®)
Contraindications (2)
Pregnancy info

Answer 4

angle-closure (narrow angle) glaucoma
also if fhey are hypersensitive to any ingredients in it (scopolamine, belladonna alkaloids)
Caution in pregnancy

Question 5

Scoplolamine Transdermal
Side effects
cautions:

Answer 5

Dec secretion of saliva (dry mouth), sweat,
Dec gastrointestinal secretions, motility, cause drowsiness, dilates pupils,
Dec heart rate
warned of the possibility and cautioned against engaging in activities that require mental alertness, such as driving a motor vehicle or operating dangerous machinery (blender, hairdryer, other normal things around the house)

Question 6

The adverse effects of __ are similar to some street drugs: ketamine, bath salts, mushrooms,

Answer 6

Scoplolamine Transdermal
rarely, idiosyncratic reactions may occur with ordinary therapeutic doses of scopolamine, the most serious of these that have been reported are: acute psychosis, confusion, agitation, rambling speech, hallucinations, paranoid behaviors, and delusions.

Question 7

Dopamine Receptor Antagonists
MoA
What is their primary use?

Answer 7

Antagonist activity at domamine D2 receptors in the chemoreceptor trigger zone (CTZ) within the brain.
Blockade dec N/V triggered by most stimuli
At higher doses, 5-HT3 antagonist activity may also inc anti-emetic effect

Primarily used to N/V, and to facilitate gastric empying in patients with gastroparesis

Question 8

ex of Dopamine Receptor Antagonist

What does it mainly do?

Answer 8

Metclopramide
Inc preistalsis of the jejunum & duodenum
Inc tone and amplitude of gastric contractions, and relaxes pyloric sphincter.

Question 9

___ is used almost exclusively in diabetics with gastroparesis.

Answer 9

Metclopramide

Question 10

Metclopramide (Reglan®)
CI (3)
Preg category
Sfx (5)

Answer 10

Contraindications: pheochromocytoma, Parkinson’s disease, suspected bowel obstruction.
Pregnancy: Cat. A
Side effects: restlessness, drowsiness, dizziness, lassitude, and/or dystonic reactions

Question 11

*What is almost the exclusive use of Metclopramide?

Answer 11

Used almost exclusively to treat gastroparesis in diabetics

Question 12

What is the gold standard to control nausea/vomiting produced by cancer chemotherapy

Answer 12

5-HT3 RAs

Question 13

5-HT3 RAs (one type of anti-emetic)
MoA?
When are they particularly effective?

Answer 13

dec activity of the vagus nerve, which activates the vomiting center in the medulla oblongata
Particularly effective in controlling N/V produced by cancer chemotherapy, and are considered the gold standard for this purpose

Question 14

5-HT receptor is also for ___. (besides nausea, vomiting)

Answer 14

migraines
migraines are more frequent in women because they have more receptors in their medulla as well as in their gut, to give them the nausea.

Question 15

5-HT3 RA
Example, route of admin
When is it used? To treat N/V from: (3)

Answer 15

Ondansetron (PO dissolving tablet, IV, IM)

Tx/prevent N/V from chemotherapy, post op, acute gastroenteritis.

Question 16

Side effects of Ordansetron (rare)

Answer 16

well-tolerated drug with few side effects; constipation, dizziness and headache are most common (but still rare)

Question 17

Substance P/Neurokinin-1 RAs

MoA:

Answer 17

Blocks signals given off by neurokinin 1 (NK1) receptors decrease likelihood of a patient experiencing N/V with chemotherapy

Question 18

ex of Substance P/NK1 RA
What’s it used for?
It is almost always used in combo with __, and frequently used with __.

Answer 18

Aprepitant
*This class is phenomenal for a chemotherapeutic patient.
It is almost always used in combination with 5-HT3 RAs (i.e., ondansetron) and frequently with dexamethasone

Question 19

Aprepitant (Emend®)
CI:
Preg category
Side effects
Adverse Events

Answer 19

Contraindications: allergy to drug or class
Pregnancy: Cat. B
Side effects: well-tolerated drug with few side effects
Adverse Events: rare

Question 20

Anti-emetics are

Answer 20

Anti-cholinergics