Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Adv Pharm 1 > GI (pt 3/5) PPIs, GI Prokinetic Drugs > Flashcards

GI (pt 3/5) PPIs, GI Prokinetic Drugs Flashcards

1
Q

PPIs inhibit ___-___% of acid secretion (!BlueBox!)

A

PPIs inhibit 90% -98% of acid secretion.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Released in the late 1980s – have assumed the major role for the treatment of acid-peptic disorders-GI Bleed or past bleed- increase dose as bolus or give 2X day then start Iv continuous.
-Among the most widely prescribed drugs in the world

A

Proton Pump Inhibitors (PPIs)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the MOA of Proton Pump Inhibitors (PPIs)?

A

Produce selective & irreversible inhibition of the proton (acid) pump enzyme system (H+/K+-ATPase) of the parietal cells of the stomach.
-Cause prolonged inhibition of gastric acid secretion regardless of the stimulus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How do PPIs compare to H2 Blockers?

A

PPIs have significantly greater inhibition than H2 Blockers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Explain the dosing/administration of PPIs.

A

-Single PO dose the night before surgery improves the pH of the gastric fluid
-No difference if taken less than 3hr before surgery (so take night before or >3 hrs before surgery)
-Duration of action ~ 24hr or more
-18 hrs required for synthesis of H+/K+-ATPase pump molecules
-Given as inactive drug-changes when coating dissolves= Prodrug

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Explain how PPIs are converted from the inactive prodrug to the activated form?

A

1) Administered as an inactive prodrug
2) In the alkaline intestinal lumen, the enteric coating dissolves and the prodrug is absorbed
3) PPIs are lipophilic weak bases (pKa 4-5), so they readily cross the lipid membranes into acidified compartments (Such as the parietal cell)
4) Prodrug rapidly becomes protonated within the canaliculus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Why are PPIs “ideal drugs” regarding pharmacokinetics? (Blue Box!!)

A

Regarding pharmacokinetics, PPIs are ideal drugs: they have a short serum half-life, they are concentrated and activated near the site of action and have a long duration of action.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Bioavailability of PPIs is decreased ___% by food.

A

Bioavailability is decreased 50% by food.
-Administer 1 hr before a meal (typically before breakfast)
-Allows for peak serum concentration to coincide with high proton-pump secretion activity
-Only 10% of pumps are working during the fasting state

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is important to know regarding PPIs and Liver impairment?

A

Dose reduction needed in severe liver impairment.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

To maximize inhibition during the first 24-28hrs, IV doses of Esomeprazole and Pantoprazole must be given as ___________ or __________.

A

To maximize inhibition during the first 24-28hrs, IV doses of Esomeprazole and Pantoprazole must be given as continuous infusions or repeated boluses.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Are all active proton pumps inhibited with the first dose of PPI?

A

No; Not all active pumps are inhibited with the first dose.
-Takes 3-4 days before the full acid-inhibiting potential in reached
-Similar 3-4 days for recovery after D/C of the drug

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Acid inhibition from PPIs last how long?

A

-Acid Inhibition lasts for up to 24 hrs
-Half-life is 1.5 hrs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the drug interactions that occur with Proton Pump Inhibitors (PPIs)?

A

-↓Gastric acidity may alter absorption of anti-fungals, anti-virals.
-All PPIs are metabolized by hepatic CYP450, so they increase concentration of drugs metabolized by these pathways.
-Specific considerations with Omeprazole, Esomeprazole, and Lansoprazole

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are the specific drug interactions that occur with Omeprazole (Prilosec)?

A

-Increases levels of Valium, Dilantin, and Coumadin
-Decreases effectiveness of Plavix (blocks an enzyme, CYP2C19, that turns Plavix into its active form).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the specific drug interactions that occur with Esomeprazole (Nexium)?

A

-Diazepam
-Decreases effectiveness of Plavix (blocks an enzyme, CYP2C19, that turns Plavix into its active form).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are the specific drug interactions that occur with Lansoprazole (Prevacid)?

A

-Theophylline

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are the specific drug interactions that occur with Rabeprazole and Pantoprazole (Protonix)?

A

No significant drug interactions.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are the adverse effects associated with PPIs?

A

In general, extremely safe drugs.
-1-5% report diarrhea, HA & ABD Pain
-↓ B12 levels & calcium absorption with prolonged use (may need B12 injections)
-↑ risk of community-acquired respiratory infections & nosocomial pneumonia
-↑ risk for hospital & community-acquired Clostridium difficile infections in patients on PPIs
-Risk of transient rebound acid hypersecretion after drug discontinuation
-Change absorption of minerals and medications (risk of Fx)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Do not give ____ or ____ to patients on Plavix.

A

Do not give Esomeprazole (Nexium) or Omeprazole (Prilosec) to patients on Plavix**

20
Q

T/F: Clopidogrel (Plavix) is a prodrug that requires activation by the hepatic P450 CYP2C19 isoenzyme, which also is involved in the metabolism of PPIs. Esomeprazole (Nexium) and Omeprazole (Prilosec) can change the activation of Plavix, making its antiplatelet actions less effective and possibly causing serious cardiovascular effects.

A

True

21
Q

What PPIs would you give to a patient taking Clopidogrel (Plavix)?

A

Pantoprazole or Rabeprazole

22
Q

What are the effects of PPIs on nocturnal acid secretion vs meal-stimulated secretion compared to H2 Blockers?

A

H2 Blockers - strong effect on nocturnal secretion, but modest effect on meal secretion.

PPIs: markedly suppress meal-stimulated AND nocturnal acid secretion.

23
Q

What is Sucralfate?

A

A salt of sucrose complexed to sulfated aluminum hydroxide.
-Forms a viscous paste in water or acidic solutions
-Selectively binds to ulcers or erosions of the gastroduodenal mucosa
-Forms a physical barrier to restrict further damage.
-Doesn’t get absorbed, so no real side effects.
-Stimulates mucosal prostaglandins and bicarbonate secretion.

24
Q

What is the clinical use for Sucralfate?

A

-Dose – 1g four times daily on an empty stomach
-Reduces the incidence of clinically significant upper GI bleeding in critically ill/ICU patients.

25
Q

What are the adverse effects associated with Sucralfate?

A

-NOT absorbed, so no real side effects.
-Virtually devoid of systemic adverse effects.

26
Q

What drug interactions occur with Sucralfate?

A

May bind to other medications 🡪 impaired absorption

27
Q

What regulates the flow of food between esophagus and stomach?

A

Lower Esophageal Sphincter

28
Q

What is the hallmark of gastric control for periop?

A

NPO past midnight

29
Q

Emptying of solids begins ___ hour after ingestion.

A

~ 1 hour

30
Q

Emptying of liquids begins within _____ of ingestion.

A

Emptying of liquids begins within 1 minute of ingestion

31
Q

What are extrinsic factors that slow gastric emptying?

A

-Food high in sugar, protein or fat
-Hypertonic solutions
-Some drugs

32
Q

What are the two ways that GI prokinetic drugs can accelerate the rate of gastric emptying?

A

1) ↑ Lower esophageal sphincter tone
2) Enhancing peristaltic contractions

33
Q

What is Neostigmine?

A

An acetylcholinesterase inhibitor that enhances gastric, small intestine, and colonic emptying.
-Used IV for the tx of hospitalized patients with acute large bowel distention.
-Used to treat colonic pseudo-obstruction (Ogilvie’s Syndrome) and Post-op Ileus

34
Q

What is Ogilvie Syndrome (Colonic Pseudo-obstruction)

A

The acute obstruction and dilation of the colon in the absence of any mechanical obstruction in severely ill patients.
-Acute large bowel distention

35
Q

What are the side effects of Neostigmine?

A

Cholinergic Effects:
-Excessive salivation
-Nausea, Vomiting, Diarrhea
-Bradycardia & Hypotension
-S-L-U-D-G-E (salivation, lacrimation, urination, diarrhea, GI, emesis)

36
Q

What is Metoclopramide (Reglan)?

A

A Dopamine D2 Receptor Antagonist.
-Benzamide class gastrointestinal prokinetic
-Acts at the chemoreceptor trigger zone of the medulla
-Mild to moderate anti-nausea & antiemetic action
-Works on post ganglionic cholinergic nerves in the GI tract, mainly on smooth muscle

37
Q

How does Metoclopramide (Reglan) cause its effects?

A

-↑Esophageal peristaltic amplitude and gastric motility
-↑Lower esophageal sphincter pressure by 10-20cm H20
-Enhances gastric emptying by relaxing pylorus and duodenum during contraction of stomach
-Decreases transit time

38
Q

What are the clinical uses for Metoclopramide (Reglan)?

A

-GERD
-Impaired gastric emptying (Postsurgical disorders, Diabetic gastroparesis, Hospitalized patients receiving nasoenteric feedings)
-Non-ulcer dyspepsia
-Prevention of vomiting
-Postpartum lactation stimulation-via Dopamine Stimulation to regulate Prolactin

39
Q

Why would Metoclopramide (Reglan) be used perioperatively?

A

To decrease gastric fluid volume.

40
Q

When would Metoclopramide be beneficial to administer perioperatively? (What patient conditions)?

A

-Patients who have recently ingested solid food
-Trauma patients
-Obese patients
-Patients with any form of gastroparesis (i.e. diabetes)
-Parturient with a history of heartburn
-Patients taking opioids

41
Q

What is the dosing instructions for Metoclopramide (Reglan) given perioperatively? (Blue Box!!)

A

-10-20mg IV over 3-5 minutes at 15-30 minutes before induction
-Renal impairment 🡪 decrease dosing
-Slow IVP - too fast will produce severe abdominal cramps in an awake patient

42
Q

What are the adverse effects of Metoclopramide (Reglan)?

A

Blocks receptors in the CNS.

Extrapyramidal effects occur in 25% of patients given high doses:
-Dystonias
-Akathisia
-Parkinsonian features
-tardive dyskinesia

EPS effects occur in 5% of patients receiving long-term therapy

43
Q

What drugs do you avoid administering with Metoclopramide (Reglan)? (Blue Box!!)

A

DO NOT ADMINISTER:
-With other dopamine antagonists (doubles risk of adverse SEs)
-With MAOIs or TCAs (blocks catecholamines)
-With Succinylcholine (prolongs action of it)

44
Q

What patient conditions do you want to avoid administration of Metoclopramide with? (Blue Box!!)

A

Do not give to patients with Parkinson’s Dz or patients with preexisting seizure disorders (lowers the seizure threshold)

45
Q

Why do you avoid the use of Succinylcholine with Metoclopramide (reglan)? (Blue Box!!)

A

Metoclopramide has an inhibitory effect on plasma cholinesterase, prolonging the action of Succ*****.
-Ex: In pregnancy, they can already have a decreased amount of plasma cholinesterase. That plus long term use of reglan, plus C-section with quick wake up (use of Succ) = prolonged effects of Succ (weakness)

46
Q

What is Erythromycin?

A

A Macrolide antibiotic
-Stimulates motilin receptors on GI smooth muscle
-Promotes the onset of a migrating motor complex
-3mg/kg IV is beneficial in gastroparesis
-Tolerance develops rapidly

47
Q

What are the clinical uses of GI drugs?

A

-GERD
-PUD
-Non-ulcer dyspepsia
-Prevention of Bleeding from stress
-H. pylori
-NSAID ulcers
-Prevention of re-bleeding from peptic ulcers
-Gastrinoma/Hypersecretory conditions like Zollinger Ellison
-Vomiting prevention
-Impaired gastric emptying

Adv Pharm 1 (28 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions