Brainscape's Knowledge GenomeTM

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


See full index

Pharmacology > Chapter 36 Antihistamines, Decongestants, Antitussives, and Expectorants > Flashcards

Chapter 36 Antihistamines, Decongestants, Antitussives, and Expectorants Flashcards

1
Q

Common colds result from a viral infection, most often
infection with a rhinovirus or an influenza virus. These
viruses invade the tissues (mucosa) of the upper respiratory tract (nose, pharynx, and larynx) to cause an?

A

upper respiratory tract infection (URI).

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

Many antihistamines, nasal decongestants, antitussives, and expectorants are available without prescription. These drugs can?

A

only relieve the symptoms of a URI; they can do nothing

to eliminate the causative pathogen.

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

Antiviral drugs are currently the only drugs that are effective for URIs; however, treatment with these medications is often hampered by the fact that the viral cause cannot be readily identified. The treatment rendered can only be based on what is believed to be the most likely cause, given the presenting clinical symptoms. This is known as?

A

empiric therapy.

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

Histamine is a substance that performs many functions. It is involved in?

A 
1) nerve impulse transmission in the central nervous
system (CNS)
2) dilation of capillaries
3) contraction of smooth muscle
4) stimulation of gastric secretion
5) acceleration of the heart rate.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

During allergic reactions, histamine and other substances are released from?

A

mast cells, basophils, and other cells in response to antigens circulating in the blood. Histamine molecules
then bind to and activate other cells in the nose, eyes, respiratory tract, gastrointestinal (GI) tract, and skin, producing the characteristic allergic signs and symptoms.

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

There are two types of histamine blockers: H1 blockers and H2 blockers

A
  • H1 blockers are the drugs to which most people
    are referring when they use the term antihistamine. H1 blockers prevent the harmful effects of histamine and are used to treat seasonal allergic rhinitis, anaphylaxis, reactions to insect bites, and so forth.
  • H2 blockers are used to treat gastric acid disorders, such as hyperacidity or ulcer disease and include cimetidine (Tagamet), ranitidine (Zantac), famotidine
    (Pepcid), and nizatidine (Axid).
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

H1 antagonists include drugs such as diphenhydramine
(Benadryl), chlorpheniramine (generic), fexofenadine
(Allegra), loratadine (Claritin), and cetirizine (Zyrtec). They
are of greatest value in the treatment of?

A

nasal allergies, particularly seasonal hay fever.
-also have palliative, not curative effects such as relieving the symptoms of the common cold such as sneezing and running nose

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

H-1 Receptor

A

Mediate smooth muscle contraction & dilation of capillaries

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

The clinical efficacy of the different antihistamines is very
similar, although they have varying degrees of?

A

antihistaminic, anticholinergic, and sedating properties.

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

Antihistamines affect the secretions of?

A

Lacrimal, salivary, and respiratory mucosal glands, which are the primary anticholinergic actions of antihistamines

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

Antihistamines differ from each other in their?

A

Potency and adverse effects, especially in degree of drowsiness they produce

  • the antihistaminic, anticholinergic, and sedative properties, they are indicated for tx of allergies
  • They are also useful for the treatment of problems such as vertigo, motion sickness, insomnia, cough, and are sometimes used as sleep aids.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Antihistamines mechanism of action

A

Block the histamine receptors on the surfaces of basophils and mast cells, thereby preventing the release and actions of histamine stored within these cells. They do NOT push off histamine that is already bound to receptors but compete with histamine for unoccupied receptors. Therefore they are most beneficial when given early in a histamine-mediated reaction before all of the free histamine molecules bind to cell membrane receptors. The binding of H1 blockers to these receptors prevents the adverse consequences of histamine binding: vasodilation; increased GI, respiratory, salivary, and lacrimal secretions; and increased capillary permeability with resultant edema.

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

Antihistamines Contraindications

A

Antihistamines are not to be used as the sole drug therapy during acute asthmatic attacks. In such cases, a rapidly acting bronchodilator such as albuterol, or in extreme cases epinephrine, is the most urgently needed medication.

  • narrow angle glaucoma, cardiac disease, kidney disease, HTN, bronchial asthma, COPD, peptic ulcer disease, seizure disorders, BPH, pregnancy
  • used in caution w/pts that have impaired liver function or renal insufficiency, as well as lactating women
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Antihistamines Adverse effects

A

Drowsiness is usually the chief complaint of people who take antihistamines.
-the anticholinergic (drying) effects: dry mouth, changes in vision, difficulty urinating, constipation

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

Antihistamine Drug: Diphenhydramine (Benadryl)

A
  • works peripherally & centrally
  • anticholinergic & sedative effects
  • hypnotic drug (sedative effects)
  • not advised in older adults due to “hangover” effect & increased potential for falls
  • excellent safety profile and efficacy
  • greatest range of therapeutic indications
  • used for relief/prevention of histamine-related allergies, motion sickness, Parkinson’s disease (anticholinergic effects)
  • used in conjunction with epinephrine in management of anaphylaxis & Tx of acute dystonic reactions
  • Pregnancy category b
  • use w/caution in: nursing mothers neonates, & pt’s w/lower respiratory tract symptoms
  • oral, parenteral, topical
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

A major advance in antihistamine therapy occurred with the development of the nonsedating antihistamines loratadine, cetirizine, and fexofenadine. These drugs were developed to eliminate many of the unwanted sedative effects of the older antihistamines. These drugs work peripherally to block the actions of histamine and therefore have significantly fewer CNS effects than many older antihistamines. For this reason, these drugs are also called peripherally acting antihistamines because they do not readily cross the blood-brain barrier.

A

.

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

Nasal congestion is due to excessive nasal secretions and inflamed and swollen nasal mucosa. The primary causes of nasal congestion are?

A

allergies and URIs, especially the common cold.

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

Decongestants work by?

A

causing constriction of the engorged and swollen blood vessels in the sinuses, which decreases pressure and allows mucous membranes to drain. It is important to understand the action of these drugs and know other important information such as significant adverse effects, including cardiac and CNS-stimulating effects.

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

There are three separate groups of nasal decongestants:

A

(1) adrenergics (sympathomimetics), which are the largest group
(2) anticholinergics (parasympatholytics), which are somewhat less commonly used
(3) selected topical corticosteroids (intranasal steroids).

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

Nasal decongestants are most commonly used for their ability to shrink engorged nasal mucous membranes and relieve nasal stuffiness. Adrenergic drugs (e.g., ephedrine, oxymetazoline) accomplish this by?

A

constricting the small arterioles that supply the structures of the upper respiratory tract, primarily the blood vessels surrounding the nasal sinuses.

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

Nasal decongestants reduce the nasal congestion associated with?

A

acute or chronic rhinitis, the common cold, sinusitis, and hay fever or other allergies. They may also be used to reduce swelling of the nasal passages and to facilitate visualization of the nasal and pharyngeal membranes before surgery or diagnostic procedures.

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

The clinical problem of rebound congestion associated with topically administered drugs is almost nonexistent with oral dosage forms. Rebound congestion occurs because of the?

A

very rapid absorption of the drug through mucous membranes followed by a more rapid decline in therapeutic activity. This can cause addiction to the nasal spray, as patients take it frequently due to the rapid decline in activity.

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

Inhaled intranasal steroids and anticholinergic drugs are not associated with rebound congestion and are often used?

A

prophylactically to prevent nasal congestion in patients with chronic upper respiratory tract symptoms.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Nasal steroids are aimed at the?

A

inflammatory response elicited by invading organisms (viruses and bacteria) or other antigens (e.g., allergens).

  • Steroids exert their antiinflammatory effect by causing these cells to be turned off or rendered unresponsive
  • goal is NOT complete immunosuppression of the respiratory tract but rather to reduce the inflammatory symptoms to improve patient comfort and air exchange
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Decongestants contraindication

A
  • Adrenergic drugs are contraindicated in narrow-angle glaucoma, uncontrolled cardiovascular disease, hypertension, diabetes, hyperthyroidism, and prostatitis and in situations in which the patient is unable to close his or her eyes (such as after a cerebrovascular accident), as well as in patients with a history of cerebrovascular accident or transient ischemic attacks, cerebral arteriosclerosis, long-standing asthma, benign prostatic hyperplasia, or diabetes.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Decongestants Adverse effects

A

Adrenergic drugs are usually well tolerated. Possible adverse effects of these drugs include nervousness, insomnia, palpitations, and tremor. The most common adverse effects of intranasal steroids are localized and include mucosal irritation and dryness.

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

Decongestants interactions

A

Systemic sympathomimetic drugs and sympathomimetic nasal decongestants are likely to cause drug toxicity when given together.

  • MAOIs may result in additive pressor effects (raising BP) when given with sympathomimetic nasal decongestants
  • methyldopa & urinary acidifiers and alkalinizers
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

The cough reflex is stimulated when?

A

Receptors in the bronchi, alveoli, and pleura (lining of the lungs) are stretched. Causing a signal to be sent to the cough center in the medulla of the brain, which in turn stimulates the cough

29
Q

Coughing is usually beneficial; however, there are times when it is not useful and may even be harmful (e.g., after a surgical procedure such as hernia repair or in cases of nonproductive or “dry” cough). The use of an?

A

antitussive drug may enhance patient comfort and reduce respiratory distress.

30
Q

There are two main categories of antitussive drugs:

A

(1) opioid and (2) nonopioid.

31
Q

Only codeine and its semisynthetic derivative hydrocodone are used as?

A

antitussives. Both drugs are effective in suppressing the cough reflex, and if they are taken in the prescribed manner, their use does not generally lead to dependency.
- used in combination with other respiratory drugs; rarely used alone for cough suppression

32
Q

Non-opiod antitussive drug:

A

Dextromethorphan (Robitussin)

33
Q

The opioid antitussives codeine and hydrocodone Mechanism of action

A

suppress the cough reflex through direct action on the cough center in the CNS (medulla). Opioid antitussives also provide analgesia and have a drying effect on the mucosa of the respiratory tract, which increases the viscosity of respiratory secretions. This helps to reduce symptoms such as runny nose and postnasal drip.

34
Q

The nonopioid cough suppressant dextromethorphan Mechanism of action

A

works in the same way as opioid antitussive. It is not an opioid and does not have analgesic properties, nor does it cause CNS depression.

35
Q

Antitussive indications

A

Stop the cough reflex when the cough is nonproductive and/or harmful

36
Q

Antitussive contraindications

A
  • Known drug allergy
  • opioid dependency
  • high risk for respiratory depression
  • Dextromethorphan: hyperthyroidism, advanced cardican and vessel disease, HTN, glaucoma, MAOIs w/in 14 days
  • Codeine: alcohol, cautious use w/CNS depression; anoxia, hypercapnia, respiratory depression; increased ICP; impaired renal function; liver diseases; BPH; COPD
37
Q

Antitussive Adverse effects drug codeine

A

Sedation, N/V, lightheadedness, constipation

38
Q

Antitussive Adverse effects drug Dextromethorphan (Robitussin)

A

Dizziness, drowsiness, N
-Patients should not drive a car or engage in other activities that require mental alertness if these adverse effects occur.

39
Q

Antitussive drug: codeine

A
  • used in combo w/respiratory meds to control coughs
  • potentially addictive & can depress respirations as part of its CNS depressant effects; so they are controlled substances
  • alone it is a schedule II drug
  • codeine containing cough suppressants are schedule V
40
Q

Antitussive drug: Dextromethorphan (Robitussin)

A
  • used alone or in combo
  • does NOT cause respiratory or CNS depression
  • contraindicated in: known drug allergy, asthma, emphysema, or persistent HA
  • available in lozenges, solution, liquid filled capsule, granules, tabs, extended release suspension
  • pregnancy C
41
Q

Expectorants aid in the expectoration of excessive mucus that has accumulated in the respiratory tract by?

A

breaking down and thinning the secretions.

42
Q

Expectorants have one of two different mechanisms of action.

A

1) Reflex stimulation causes loosening and thinning of respiratory tract secretions in response to an irritation of the GI tract produced by the drug; guaifenesin is the only drug currently available with this mechanism of action.
2) direct stimulation of the secretory glands in the respiratory tract.

43
Q

Expectorants indications

A

relief of productive cough commonly associated with the common cold, bronchitis, laryngitis, pharyngitis, pertussis, influenza, and measles and may be used for the suppression of coughs caused by chronic paranasal sinusitis. By loosening and thinning sputum and bronchial secretions, they may also indirectly diminish cough.

44
Q

Adverse effects of expectorants

Drug Guaifenesin

A

N/V, gastric irritation

45
Q

expectorants Drug: Guaifenesin

A
  • several oral forms: capsule, tabs, solutions, granules

- half life of 1 hour

46
Q

Nursing assessment: when a pt is taking drugs to treat symptoms related to respiratory tract, first asses if symptoms may be reflective of?

A

An allergic reaction

47
Q

With the traditional and nontraditional antihistamines, if
allergy testing is to be performed, these medications are
usually discontinued at least?

A

4 days before the testing, but only on a prescriber’s order and as directed.

48
Q

With the use of the antihistamines; Diphenhydramine (Benadryl) & Cetirizine (Zyrtec) the patient should avoid?

A

Alcohol, MAOIs, and CNS depressants, which can lead to CNS depression

49
Q

Use of antihistamines is of concern in patients who are experiencing an?

A

acute asthma attack and in those who have lower
respiratory tract disease or are at risk for pneumonia. Antihistamines dry up secretions; if the patient cannot expectorate the secretions, the secretions may become viscous, occlude airways, and lead to atelectasis or further infection or occlusion of the bronchioles.
-these drugs may lead to paradoxical reactions in older adults, with subsequent irritability as well as dizziness, confusion, sedation, and hypotension

50
Q

Decongestants may increase?

A

blood pressure and heart rate, so assess and document the patient’s blood pressure, pulse, and other vital parameters.
- Many of these drugs are found in OTC cough and cold
products and have been associated with numerous cases of oversedation, seizures, tachycardia, and even death; their use warrants extreme caution.

51
Q

Contraindications to the use of decongestants

A
  • known drug allergy
  • narrow-angle glaucoma
  • uncontrolled cardiovascular disease
  • HTN
  • diabetes
  • prostatitis
52
Q

Sedative effects are much less common, although still possible, with the newer “nonsedative” drugs. With antitussive therapy, most of the drugs result in sedation, dizziness, and drowsiness, so assessment of the patient’s safety is very important. Caution patients against?

A

driving a car or engaging in other activities that require mental alertness until they feel back to normal. If the antitussive contains codeine, the CNS depressant effects of the narcotic opiate may further depress breathing and respiratory effort.

53
Q

The H1 receptor antagonist drugs do not cross the blood brain barrier as readily as do older antihistamines and therefore are?

A

less likely to cause sedation. Generally well tolerated w/minimal adverse effects

54
Q

Instruct pt taking traditional antihistamines to take the medications as prescribed. Most of these medications, including OTC antihistamines, are best when?

A

tolerated when taken with meals

-food may slightly decrease absorption, it has a benefit of minimizing the GI upset

55
Q

Can you take OTC or prescribed cold or cough medications with antihistamines?

A

NO. unless they were approved because there could be potential for serious drug interactions

56
Q

Monitor adults and children for any?

A

Paradoxical reactions, common with these drugs

57
Q

With oral decongestants educate the patient on?

A

Taking all dosage forms as instructed and with an increase in fluid intake of up to 3000 mL/day
-fluid helps to liquify secretions, assists in breaking thick secretions, easier to cough up secretions

58
Q

With nasal decongestants take it

A

Exactly as ordered, no increase in frequency

59
Q

Give antitussives at evenly spaced intervals so drug can reach steady state

A

.

60
Q

With traditional and nonsedating antihistamines, what can be used to help liquefy secretions?

A

A humidifier. Also encourage intake of fluids

61
Q

Instruct the patient to take antitussives with caution and to report any?

A

Fever, chest tightness, change in sputum from clear to colored, difficult or noisy breathing, activity intolerance, or weakness

62
Q

With decongestants educate patient on?

A
  • rebound congestion with excessive use

- report: dizziness, heart palpitations, weakness, sedation, excessive irritability

63
Q

Patient education for expectorants

A
  • avoid alcohol and products containing it
  • don’t use these meds for longer than 1 week
  • encourage fluid intake (thin mucous)
64
Q

Decongestants and expectorants are recommended to treat cold symptoms, but the patient must report?

A

A fever of higher than 100.4 F (38 C), cough, or other symptoms lasting longer than 3-4 days

65
Q 
What body system will the nurse assess for known common adverse effects of traditional antihistamines?
  Respiratory
  Cardiovascular
  Central nervous
  Gastrointestinal
A

Central nervous
The most common adverse effect of antihistamines is drowsiness, but the sedative effects vary among antihistamine drug classes

66
Q 
The nurse is discussing use of antitussive medications with a client. What common adverse effect does the nurse include in the client teaching?
  Tremors and palpitations
  Drowsiness and dizziness
  Diarrhea and abdominal cramping
  Flushing and decreased heart rate
A

Drowsiness and dizziness
Antitussive medications suppress cough through its action on the central nervous system, thus causing drowsiness and dizziness.

67
Q 
The nurse would question a prescription for pseudoephedrine (Sudafed) in a client with a history of which condition?
  Pneumonia
  Osteoporosis
  Hypertension
  Peptic ulcer disease
A

Adrenergic drugs are contraindicated in clients with hypertension, narrow-angle glaucoma, diabetes, uncontrolled cardiovascular disease, hyperthyroidism, prostatitis, or a known hypersensitivity to such drugs.

68
Q 
The nurse is providing education to a client with a history of chronic nasal congestion secondary to allergic rhinitis. Which class of medications should the nurse anticipate the provider would recommend for the client to use on a long-term basis?
  Antitussives
  Expectorants
  Antihistamines
  Intranasal steroids
A

Intranasal steroids

Inhaled intranasal steroids and anticholinergic drugs are not associated with rebound congestion and are often used prophylactically to prevent nasal congestion in clients with chronic upper respiratory tract symptoms. Local intranasal steroids would have the least likely possible systemic adverse effects of all the medication classes possible to use for chronic and long term use.

Pharmacology (28 decks)

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