Lecture 4 (Antiemetic and Antianginal Drugs)

Question 1

what is emesis?

Answer 1

• forcible emptying of gastric acid and stomach contents
• occasionally intestinal contents as well

Question 2

what are antiemetic drugs used for?

Answer 2

used to relieve nausea and vomiting

Question 3

what stimulates vomiting?

Answer 3

• Vomiting center (VC)
• chemoreceptor trigger zone (CTZ)
  both located in the brain, when stimulated cause vomiting reflex

Question 4

what are the different types of nausea and vomiting?

Answer 4

1) chemotherapy induced
2) post operative
3) general

Question 5

describe the signal pathways that cause nausea and vomiting(3)

Answer 5

1) the gastrointestinal tract, labyrinth (inner ear), and cerebral cortex sends signals to the chemoreceptor trigger zone (CTZ)

2) the chemoreceptor trigger zone (CTZ) sends a signal to the vomiting center in the medulla

3) the vomiting center in the medulla initiates the vomiting reflex

Question 6

what is the mechanisms of action of antiemetics?

Answer 6

antiemetics work by blocking one of the vomiting pathways which blocks the stimulus that induces vomiting

Question 7

what is the general use for each type of antiemetic?

Answer 7

the prevention and reduction of nausea and vomiting

Question 8

what are two antiemetics?

Answer 8

1) prokinetic metoclopramide (Reglan)
2) serotonin blockers ondansetron (Zofran)

Question 9

what is the mechanism of action for metaclopramide (Reglan)?

Answer 9

• blocks dopamine receptors in the CTZ
• causes CTZ to be desensitized to impulses it receives from the GI tract

Question 10

what does metaclopramide (Reglan) do to peristalsis?

Answer 10

it stimulates peristalsis in the GI tract which enhances emptying of stomach contents

Question 11

what is metaclopramide (Reglan) and what is it used for?

Answer 11

it is an antiemetic used to treat nausea and vomiting, but it is also used for:
* gastroesophageal reflux disease
* delayed gastric emptying

Question 12

what are the adverse effects related to metaclopramide (Reglan)(9)?

Answer 12

1) hypotension
2) supraventricular tachycardia
3) sedation
4) fatigue
5) restlessness
6) dry mouth
7) nausea & vomiting
8) diarrhea
9) irreversible tardive dyskinesia (if used long-term)

Question 13

what is tardive dyskinesia?

Answer 13

chronic condition that causes involuntary repetitive face and jaw movements

Question 14

what is ondansetron (Zofran) and what is it used for?

Answer 14

it is an antiemetic that is used for nausea and vomiting in:
* patients receiving chemotherapy
* post operative patients

Question 15

what is the mechanism of action of ondansetron (Zofran)?

Answer 15

blocks serotonin receptors in the GI tract, CTZ, and VC

Question 16

what are the adverse effects associated with ondansetron (Zofran)(4)?

Answer 16

1) headache
2) diarrhea
3) rash
4) bronchospasm

Question 17

why do you need to warn patients about driving or performing hazardous work while on antiemetics?

Answer 17

they can cause severe drowsiness

Question 18

why should patients on antiemetics avoid alcohol?

Answer 18

when taken together they can cause severe central nervous system depression

Question 18

why should you teach patients on antiemetics to change positions slowly?

Answer 18

to avoid hypotensive effects

Question 19

for chemotherapy, antiemetics are given when?

Answer 19

30 - 60 minutes before chemotherapy

Question 20

what is angina pectoris?

Answer 20

chest pain

Question 21

what issues with the heart causes angina pectoris?

Answer 21

when the supply of O2 and nutrients in the blood is insufficient to meet the demands of the heart, the heart muscle aches

Question 22

what is ischemia?

Answer 22

poor blood supply to an organ

Question 23

what causes ischemic heart disease?

Answer 23

1) poor blood supply to the heart
2) Atherosclerosis
3) Coronary artery disease

Question 24

what does MI do to the tissue of the heart?

Answer 24

causes necrosis of the cardiac tissue

Question 25

how does a heart attack occur?

Answer 25

occurs when a portion of the heart is deprived of oxygen due to blockage of a coronary artery

Question 26

describe the different types of angina

Answer 26

1) chronic stable angina: triggered by physical exercise or stress

2) unstable angina: pre-infarction- chest pain 24 hours before a MI

3) vasospastic angina: recurring episodes of chest pain at rest and at bedtime from midnight to 0800; can be expressed at chest discomfort or pain to neck, jaw, shoulder, or arm

Question 27

what are/is nitrates; nitroglycerine?

Answer 27

rapid acting forms
1) used to treat acute angina attacks
2) available in sublingual and IV infusion
nitroglycerine (both rapid and long-acting)
1) prototypical nitrate
2) large first-pass effect with oral forms
3) used for symptomatic treatment of ischemic heart conditions (angina)

Question 28

apart from angina, what else is nitroglycerine used for?

Answer 28

IV form used for:
* BP control in perioperative hypertension
* treatment of heart failure
* ischemic pain
* pulmonary edema associated with acute MI
* hypertensive emergencies

Question 29

what is the mechanism of action of nitrates?

Answer 29

1) causes vasodilation by relaxing smooth muscles of the blood vessels (including coronary arteries).
2) allows O2 to get to ischemic myocardial tissue
used for prevention and treatment of angina

Question 30

what are the therapeutic effects associated with nitrates?

Answer 30

1) minimize the frequency of attacks and decrease the duration and intensity of anginal pain
2) improve the patient’s functional capacity with as few adverse effects as possible
3) prevent or delay the worst possible outcome (MI)

Question 31

what are the adverse effects associated with nitrates(4)?

Answer 31

1) headaches (usually get less severe with frequent use)
2) reflex tachycardia
3) postural hypotension
4) tolerance may develop

Question 32

what are the contraindications associated with nitrates(5)?

Answer 32

1) known drug allergy
2) severe anemia
3) closed-angle glaucoma
4) severe head injury
5) use of ED drugs sildenafil (Viagra), tadalafil (Cialis), and vardenafil (Levitra)

Question 33

what is the most important drug used in the treatment of ischemic heart conditions such as angina?

Answer 33

nitroglycerin

Question 34

drug dosage information for nitroglycerin
* routes
* onset of action
* peak
* elimination half-life
* duration of action

Answer 34

• routes: PO, SL, metered-dose aerosol (sprayed under tongue), IV, and topical
• dosage: SL-0.4 mg or 1-2 sprays oral
• onset of action: 2-3 minutes
• peak: unknown
• elimination half-life: 1-4 minutes
• duration of action: 0.5-1 hour

Question 35

what do you need to obtain before giving nitroglycerin?

Answer 35

• baseline vitals including respiratory patterns and rate
• assess for drug interactions

Question 36

what should patients be encouraged to limit while taking nitroglycerin?

Answer 36

caffeine intake

Question 37

what are some things patients should report while taking nitroglycerin(8)?

Answer 37

1) blurred vision
2) persistent headache
3) dry mouth
4) edema
5) fainting episodes
6) weight gain of 2 lbs. in one day or 5 lbs. in one week
7) pulse of less than 60 bpm
8) dyspnea

Question 38

what are some things that can increase the risk of fainting while on nitroglycerin? why?

Answer 38

1) alcohol consumption
2) spending time in hot tubs, hot baths, or saunas
these cause vasodilation. paired with nitroglycerin, they can cause fainting

Question 39

patients on nitroglycerin should be encouraged to keep a record of anginal attacks. what should be included in that record?

Answer 39

1) precipitating factors
2) number of pills taken
3) therapeutic effects of the medication (how well did they help?)

Question 40

what does a burning sensation in the mouth with SL nitroglycerin indicate?

Answer 40

that the drug is still potent

Question 41

how long is SL nitroglycerin good for?

Answer 41

about 3 months after opening; patients should keep a fresh bottle on them at all times

Question 42

how do you preserve the potency of nitroglycerin?

Answer 42

store in an airtight dark glass bottle with a metal cap and no cotton filler

Question 43

what should patients take nitroglycerin?

Answer 43

NPO at the first hint of anginal pain

Question 44

when do you monitor vital signs in patient with angina?

Answer 44

during acute exacerbations of angina and during IV administration of nitroglycerin

Question 45

if a patient is experiencing anginal pain and needs to take nitroglycerin, what should they do?

Answer 45

lie down to prevent or decrease dizziness and fainting that may occur due to nitroglycerin related hypotension

Question 46

if anginal pain occurs, what should people do(3)?

Answer 46

1) stop activity, sit or lie down, and take a SL nitroglycerin tablet

2) if there is no relief in 5 minutes, call 911 and take a second tablet

3) if there is no relief in 5 minutes take a third tablet

DO NOT TRY TO DRIVE TO THE HOSPITAL