Brainscape's Knowledge GenomeTM

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


See full index

2-Pharm Final > Antihistamines > Flashcards

Antihistamines Flashcards

1
Q

What are the different types of antihistamines that have antiemetic properties?

A
  • Promethazine (Phenergan)
  • Dimenhydrinate (Dramamine)
  • Meclizine (Antivert)
  • Diphenhydramine (Benadryl)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What does histamine evoke?

A

GI smooth muscle contraction via H1 receptors and inositol phospholipid hydrolysis

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

Define Histamine inositol phospholipid hydrolysis.

A

Inositol phospholipid hydrolysis has been implicated in the mobilization of cytosolic calcium following receptor activation in several neurotransmitter and hormonal systems

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

Where are histamine receptors present?

A

Histamine receptors present in the CTZ (area postrema) and vomiting center (nucleus of the tractus solitarius)

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

What are some Nonspecific antihistamines used as antiemetics?

A

diphenhydramine, dimenhydrinate, meclizine, promethazine

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

What are the sit of action of many H1 receptor antagonists?

A

have anticholinergic effects & block muscarinic receptors in the vestibular system

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

What is Dimenhydrinate (Dramamine)?

A

used to treat motion sickness and decrease incidence of N&V with children after strabismus surgery (0.5 mg/kg IV)

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

What is Diphenhydramine (Benadryl) used for?

A

used in PONV mgmt.

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

What are the most side effects of antihistamines?

A

anticholinergic effects (dry mouth, somnolence)

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

What are examples of Neurokinin-1 Antagonists?

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

Define neurokinin-1.

A

is a centrally & peripherally expressed G-protein-coupled receptor, primary ligand: substance P

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

Where is neurokinin-1 expression?

A

Neurokinin-1 expression in nucleus tractus solitarius & area postrema: vomiting center and CTZ

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

What is the availablity of Aprepitant?

A

Aprepitant available only as an oral capsule; dose – 40mg within 3 hours of induction of anesthesia for PONV prophylaxis

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

What is the recommendation for Aprepitant & Fosaprepitant?

A
  • Expensive
  • recommended only for high-risk PONV patients for whom vomiting would compromise surgical repair
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the metabolism of Aprepitant & Fosaprepitant?

A

Metabolized by P450 CYP3A4 enzyme

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

What are Antacids & GI Motility Drugs used to prevent?

A

Used for prevention of aspiration

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

Define aspiration.

A

inhalation of gastric or oropharyngeal contents into the lungs

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

What does aspiration increase?

A

increases risk of ICU admission, longer hospital length of stay, and increased mortality

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

What do Antacids & GI Motility Drugs control?

A

Antacids & GI motility drugs control the volume and acidity of gastric contents

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the MOA of Oral Antacids?

A

Medications that neutralize H+ ions from gastric contents or ↓ secretion of HCL into the stomach

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are the components of oral antacids?

A

Oral antacids are salts of Al, Mg++, Ca++; hydrogen ions in the stomach react with the base; as hydrogen ions are consumed, the pH of stomach contents increase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What antacids are preferred?

A

Nonparticulate antacids such as sodium citrate (Bicitra) preferred

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Why is sodium citrate preferred?

A
  • Less likely to induce foreign body reaction in the lungs if aspirated
  • Mixing with gastric fluid (neutralizes) more complete & rapid than particulate antacids
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is the dose of sodium citrate?

A

15-30 ml 15-30 minutes before induction effective in increasing gastric fluid pH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is the contraindication of sodium citrate?

A

Contraindicated in patients with renal impairment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What does histamine cause?

A

Histamine causes contraction of smooth muscles in airways, ↑ secretion of stomach acids, ↑ CNS neurotransmitter release

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

How are Histamine-receptor Antagonists classified?

A

H1 to H4 receptors identified – drugs classified as H1 to H4 receptor antagonists

28
Q

What do histamine antagonists bind to?

A

Histamine antagonists bind to receptors on effector cell membrane; these drugs don’t inhibit release of histamine but rather bind to receptors to prevent histamine mediated responses

29
Q

Which Histamine-receptor Antagonists are important in anesthesia?

A

H1 & H2 receptors

30
Q

What is the components of 1st generation histamine-1 antagonists?

A

produce sedation/impaired cognition and may activate other receptors (i.e., anticholinergic - dry mouth, blurred vision, urinary retention, tachycardia)

31
Q

What is the components of 2nd generation histamine-1 antagonists?

A

more selective for H1 receptor

32
Q

What is examples of 2nd generation histamine-1 antagonists?

A

cetirizine, fexofenadine, loratadine, azelastine

33
Q

What is the toxicity of 2nd generation histamine-1 antagonists?

A

Less CNS toxicity (less sedation & less impaired cognition)

34
Q

What are the clinical uses of Histamine Receptor Antagonists?

A

Clinical uses (urticaria, allergic rhinoconjunctivitis, antipruritic, antiemetic, sedative)

35
Q

Where are histamine receptors rich?

A

Myocardium and coronary vasculature rich with histamine receptors

36
Q

Myocardium and coronary vasculature prone to the effects of _________

A

histamine release

37
Q

What can H1 and H2 blockers be used with?

A

Use of H1 and H2 blockers with epinephrine used for anaphylactic reactions

38
Q

What is the use of H1 and H2 blockers with corticosteroids?

A

Use of H1 and H2 blockers with corticosteroid used preemptively in patients with increased likelihood of allergic reactions such as with radiographic contrast dye

39
Q

What are examples of H2- Receptor Antagonists?

A

cimetidine, ranitidine, famotidine, & nizatidine

40
Q

What do H2- Receptor Antagonists inhibit?

A

Inhibit selective H2 mediated secretion of hydrogen ions by parietal cells in the stomach

41
Q

What is the MOA of H2- Receptor Antagonists?

A

Histamine released from mast cells activates cAMP within gastric parietal cells which ↑ H+ ion secretion

42
Q

What is the most potent H2- Receptor Antagonists?

A

Famotidine

43
Q

What is the least potent H2- Receptor Antagonists?

A

cimetidine

44
Q

What is the elimination of H2- Receptor Antagonists? What disease effects this?

A
  • hepatic & renal
  • renal failure increases elim half-life (decreased doses recommended in patients w/renal dysfunction)
45
Q

What does cimetidine interfere with?

A

interferes w/drug metabolism by CYP450 enzymes

46
Q

What are the clinical uses of H2- Receptor Antagonists?

A
  • Duodenal ulcer disease asso/w hypersecretion of gastric H+ ions
  • Used to increase pH of gastric fluid before induction of anesthesia
  • Routine use as a preop chemoprophylaxis to ↑ gastric pH not recommended
47
Q

What is not influenced by H2- Receptor Antagonists?

A

No influence on pH of gastric fluid already in the stomach

48
Q

What can H2- Receptor Antagonists reduce the risk of? What medications are more likely (2)?

A

May be used to reduce risk of acid pneumonitis if aspiration were to occur in perioperative period (cimetidine or famotidine)

49
Q

What can H1 and H2 antagonists be used preoperative for?

A

Preoperative preparation of patients w/allergic histories or likelihood of allergic reactions (radiographic contrast dye administration) may include prophylactic pretreatment with an H1 and H2 antagonist

50
Q

What is true about the sie effects of H2- Receptor Antagonists?

A

Overall, frequency of side effects low

51
Q

When are side effects at increased risk of occuring with H2- Receptor Antagonists?

A

Increased risk for adverse side effects w/hepatic or renal dysfunction, advanced age

52
Q

What EKG effects are associated with H2- Receptor Antagonists?

A
  • Cardiac arrhythmias (sinus brady, sinus arrest, idioventricular escape rhythm, complete heart block) have occurred after chronic oral or IV administration
  • Prolonged QTc interval & cardiac arrest w/famotidine has been reported
53
Q

What hemodynamic effects can occur with H2- Receptor Antagonists?

A

Bradycardia & hypotension asso/w rapid IV administration (critically ill or older patients)

54
Q

What is the administration of H2- Receptor Antagonists?

A

Administer IV over 15-30 minutes

55
Q

Which H2- Receptor Antagonists is most implicated in numerous drug interactions?

A

Cimetidine

56
Q

What is the characteristics of cimetidine drug interactions?

A

Binds to heme portion of P450 oxidase system

57
Q

What can H2 blockers interfere with?

A

H2 blockers can interfere with the gastric absorption and renal excretion of certain drugs

58
Q

What are examples of proton pump inhibitors?

A
  • Omeprazole
  • Esomeprazole
  • Lansoprazole
  • Pantoprazole
  • Rabeprazole
59
Q

What is the most effect drugs for available for controlling gastric acidty & volume?

A

Proton Pump Inhibitors (PPIs)

60
Q

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

A

The proton pump (hydrogen-potassium-ATPase) moves hydrogen ions across the gastric parietal cell membranes in exchange for potassium ions

61
Q

What do PPIs control?

A

PPIs control gastric acidity and volume by irreversibly blocking the proton pump which reduces gastric HCl acid secretion

62
Q

What are other clinical uses of Proton Pump Inhibitors (PPIs)?

A

PPIs are more effective than H2 antagonists in healing esophagitis & relieving heartburn

63
Q

What is the effect of Omeprazole (Prilosec)?

A

Effectively increases gastric pH & decreases gastric fluid volume

64
Q

What is the dse of Omeprazole (Prilosec)?

A

Oral dose (20 mg) should be administered > 3 hrs before induction of anesthesia to raise gastric pH in patients for whom chemoprophylaxis is desired

65
Q

What are side effects of Omeprazole (Prilosec)?

A

Can cause headaches, agitation, confusion, GI side effects

2-Pharm Final (10 decks)

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