Ch 36 Antihistamines, Decongestants, Antitussives and Expectorants

Question 1

What are the primary anticholinergic actions of Histamines?

Answer 1

They affect the secretions of lacrimal, salivary and respiratory mucosal glands.

Question 2

What are the functions of the bodily substance: Histamine?

Answer 2

• Nerve impulses in CNS
• Dilation of capillaries
• Contraction of smooth muscles
• Stimulation of gastric secretions
• ⬆ of HR

Question 3

To regulate the actions of histamine, antihistamine drugs can be administered. What are their functions?

Answer 3

Antihistamines:

• Relax the extravascular smooth muscle of the respiratory tract
• Prevent or alleviate itching
• Prevent the release and actions of histamine

Question 4

What are the indications of Antihistamines?

Answer 4

• Nasal allergies
• Seasonal or perennial allergic rhinitis (hay fever)
• Relief of some of the typical symptoms of the common cold
• Allergic reactions
• Motion sickness
• Parkinson’s disease (anticholinergic effects)
• Vertigo
• Sleep aid

Question 5

What are the contraindications with the use of Antihistamines?

Answer 5

• Narrow angle glaucoma
• ❤ disease
• Kidney disease
• Hypertension
• Bronchial asthma
• COPD
• Peptic ulcer
• Seizure disorder
• Benign prostatic hyperplasia
• Pregnancy

Question 6

What are the adverse effects of Antihistamines?

Answer 6

• Drowsiness
• Dry mouth
• Changes in vision
• Difficulty urinating
• Constipation, diarrhea
• ❤ dysrhythmias

Question 7

What are some drug interactions w/ Antihistamines that the nurse should be aware of?

Answer 7

• Alcohol
• MAOIs
• CNS depressants
• Apple, grapefruit and orange juices
• St John’s wort

Question 8

What are the 2 advantages and 1 disadvantage of oral decongestants?

Answer 8

Advantages:

• Oral route decongestants produce prolonged effects
• No rebound congestion

Disadvantage:
- Onset of action is more delayed and effect less potent

Question 9

What are the 1 advantage and the 1 disadvantage of topical decongestants?

Answer 9

Advantage:
- Quick onset of action

Disadvantage:
- Rebound congestion

Question 10

What are the advantages of inhaled decongestants?

Answer 10

Advantages:

• No rebound congestion
• Prevention of nasal congestion in pts w/ URI symptoms

Question 11

What is the mechanism of action of the adrenergic nasal decongestants?

Answer 11

They shrink nasal mucous membranes and relieve nasal stuffiness by constricting the small arterioles of the upper respiratory tract (nasal sinuses).

Question 12

What is the mechanism of action of steroid nasal decongestants?

Answer 12

They reduce the inflammatory response elicited by invading organisms (viruses + bacteria)
–> result = modulation of inflammatory symptoms to improve patient comfort and air exchange

Question 13

What are the indications of nasal decongestants?

Answer 13

• Acute or chronic rhinitis
• Common cold
• Sinusitis
• Hay fever
• Other allergies

*Can also be used prior to surgery to facilitate nasal visualization

Question 14

What are the contraindications of nasal decongestants?

Answer 14

• Narrow angle glaucoma
• Uncontrolled cardiovascular disease
• Hypertension
• Diabetes
• Hyperthyroidism
• Prostatitis
• Post CVA

Question 15

What are the adverse effects of nasal decongestants?

1) Adrenergics
2) Steroids

Answer 15

1) Adrenergics:
- Nervousness
- Insomnia
- Palpitations
- Tremors (due to stimulation of the ❤, blood vessels and CNS)

2) Steroids:
- Local mucosal dryness and irritation

Question 16

What drug interactions can be seen w/ decongestants?

Answer 16

• Systemic sympathomimetic drugs and sympathomimetic nasal decongestants are more likely to cause drug toxicity when given together.
• MAOIs may result in additive pressor effects

Question 17

What are the 2 main category of Antitussives?

Answer 17

1) Opioid

2) Nonopioid

Question 18

What are the only 2 opioids given as Antitussives?

Answer 18

• Codeine

- Semisynthetic derivative hydrocodone

Question 19

What is the difference between opioid and nonopioid Antitussives?

Answer 19

Nonopioids are less effective and can be taken alone or in combo w/ other OTC cold and cough preparations.

Question 20

How are the opioid and nonopioid Antitussives effective?

Answer 20

Opioids provide analgesia and have a drying effect –> ⬆ viscosity of respiratory secretions.
Nonopioids do the same w/out the analgesic effect

Result = ⬇ of symptoms such as runny nose and postnasal drip

Question 21

What is the main indication of Antitussives?

Answer 21

To stop the cough reflex when the cough is nonproductive and/or harmful.

Question 22

What are 2 examples of nonopioid Antitussives?

Answer 22

• Benzonatate (Tessalon Perles)

- Dectromethorphan (Vicks Formula, Robitussin-DM)

Question 23

What are the adverse effects of Antitussives?

Answer 23

1) Benzonatate:
- Dizziness, headache, sedation, nausea

2) Dextromethorphan:
- Dizziness, drowsiness, nausea

3) Opioids (Codeine + Hydromorphone):
- Sedation, nausea, vomiting, lightheadedness, constipation

Question 24

What is the primary function of the expectorants?

Answer 24

To break down and thin out the secretions.

Question 25

What is an example of an expectorant?

Answer 25

Quaifenesin (Mucinex)

Question 26

What are the indications of Expectorants?

Answer 26

Relief of productive cough commonly associated w/:

• Common cold
• Bronchitis
• Laryngitis
• Pharyngitis
• Pertussis
• Influenza
• Measles

Question 27

What are the 3 adverse effects of the expectorant Quaifenesin?

Answer 27

• Nausea
• Vomiting
• Gastric irritation

Question 28

What are the nursing implications in concerns to the Expectorants?

Answer 28

• Caution w/ elderly, asthma and respiratory insufficiency patients
• Encourage ⬆ fluids to help loosen secretions
• Patients should report: fever, cough or other symptoms lasting more than 1 week

Question 29

What are the nursing implications in concerns to Antihistamines?

Answer 29

• Caution = Contraindicated in presence of acute asthma attacks + lower respiratory diseases (pneumonia)
• Instruct patient to REPORT: excessive sedation, confusion and ⬇ BP
• Caution w/ driving and operating machinery (+ alcohol and other CNS depressants)
• Take medications w/ food to avoid GI upset
• If dry mouth = frequent mouth care, chew gum, sugar less candy

Question 30

What are the nursing implication in concerns to nasal decongestants?

Answer 30

• Monitor for adverse effects such as hypertension, palpitations and CNS stimulation (Avoid caffeine!)
• Instruct patient to REPORT fever, cough, or other symptoms lasting more than 1 week

Question 31

What are the nursing implications in concerns to Antitussives?

Answer 31

• Perform respiratory and cough assessment and assess for allergies
• Instruct patient to avoid driving and operating heavy machinery
• Patients taking chewable tablets or lozenges should not drink liquids for 30 to 35 min afterwards
• ⬆ fiber and fluid intake w/ opioids to avoid constipation
• Instruct patient to REPORT cough that lasts more than 1 week, persistent headache, fever and rash!
• ONLY use Antitussives for NONPRODUCTIVE cough

Question 32

What is the difference between H1 histamine blocker and H2 histamine blocker?

Answer 32

H1 are used to treat seasonal allergies, rhinitis, reactions to insect bites…
H2 are used to treat gastric disorders such as hyperacidity or ulcer disease