Module 3: Drugs for Allergic Rhinitis, Cough, and Colds

Question 1

Allergic Rhinitis

Answer 1

Inflammatory disorder of the upper airway, lower
airway, and eyes
 Symptoms
 Sneezing
 Rhinorrhea
 Pruritus
 Nasal congestion
 For some people: Conjunctivitis, sinusitis, and asthma

Seasonal and perennial
 Triggered by airborne allergens
 Allergens bind to immunoglobulin E (IgE) on
mast cells
 Triggers release of inflammatory mediators
 Histamine, leukotrienes, prostaglandins

Question 2

Classes of Drugs Used
for Allergic Rhinitis

Answer 2

 Glucocorticoids (intranasal)
 Antihistamines (oral and intranasal)
 Sympathomimetics (oral and intranasal)

Question 3

Intranasal Glucocorticoids

Answer 3

First choice—most effective for treatment and
prevention of rhinitis
 Mild adverse effects
 Drying of nasal mucosa or sore throat
 Epistaxis (nosebleed)
 Headache
 Rarely, systemic effects (adrenal suppression and
slowing of linear pediatric growth)

Question 4

Oral Antihistamines

Answer 4

For allergic rhinitis
 Do not reduce nasal congestion
 Most effective if taken prophylactically
 Should be taken regularly throughout the allergy
season, even when symptoms are absent, to
prevent an initial histamine receptor activation
 Mild adverse effects: Sedation with first
generation (much less with second generation)

Question 5

Intranasal Antihistamines:
Azelastine and Olopatadine

Answer 5

Indicated for allergic rhinitis in adults and in
children over 12 years old
 Systemic absorption can be sufficient to cause
somnolence
 Nosebleeds
 Anticholinergic effects
 Unpleasant taste

Question 6

Intranasal Cromolyn Sodium

Answer 6

Reduces symptoms by suppressing release of
histamine and other inflammatory mediators
from mast cells
 Prophylaxis
 Administer before symptoms start
 Response develops in 1 to 2 weeks
 Minimal adverse reactions: Less than with any
other drug for allergic rhinitis

Question 7

Sympathomimetics (Oral/Nasal)

Answer 7

Factors in topical administration
 Should not use longer than 5 consecutive days
 Drops or sprays
 Comparison: Drops versus sprays
 Topical agents act more quickly than oral agents and are usually more effective
 Oral agents act longer than topical preparations
 Systemic effects occur primarily with oral agents; topical agents usually elicit these responses only when dosage is higher than recommended
 Rebound congestion is common with prolonged use of topical agents but rare with oral agents

Phenylephrine, ephedrine, pseudoephedrine
 Antihistamine-sympathomimetic combinations
-Ipratropium bromide [Atrovent]
-Montelukast [Singulair]
-Omalizumab [Xolair]

Question 8

Sympathomimetics

Answer 8

Reduce nasal congestion (do not reduce
rhinorrhea, sneezing, or itching)
 Activate alpha1-adrenergic receptors on nasal
blood vessels
 Adverse effects
 Rebound congestion
 CNS stimulation
 Cardiovascular effects and stroke
 Abuse

Question 9

Drugs for Cough

Answer 9

Antitussives are medications designed to suppress coughing and are commonly used in the treatment of non-productive (dry) coughs. They can be particularly useful when a cough is severe and disruptive, or when it prevents restful sleep. Antitussives are classified into opioid and nonopioid categories based on their active ingredients and mechanisms of action.

Opioid Antitussives
Opioid antitussives work by acting on the cough center in the brain to reduce the cough reflex.

Codeine: A well-known opioid that is effective in suppressing cough but is also associated with the risk of dependence and abuse. Due to its opioid effects, it can cause sedation, constipation, and respiratory depression, especially in higher doses. Codeine is often combined with other medications, such as paracetamol (acetaminophen) or antihistamines, in cough and cold preparations.

Hydrocodone: Another opioid with potent antitussive properties, hydrocodone is usually reserved for more severe coughs. Like codeine, it carries risks of sedation, constipation, respiratory depression, and potential for abuse and dependence.

Nonopioid Antitussives
Nonopioid antitussives act through various mechanisms to suppress cough without the risk of opioid-related side effects.

Dextromethorphan (DXM): A common ingredient in many over-the-counter cough remedies, dextromethorphan is effective in suppressing cough by acting on the cough center in the brain, similar to opioids, but without their potential for abuse and dependence. However, at high doses, DXM can cause psychoactive effects.

Diphenhydramine: An antihistamine with sedative properties, diphenhydramine can also serve as an effective antitussive, particularly for coughs associated with allergic reactions. Its side effects include sedation, dry mouth, blurred vision, and urinary retention.

Benzonatate: A non-narcotic antitussive, benzonatate numbs the stretch receptors in the lungs and airways that are involved in the cough reflex. It is effective in relieving cough and does not have the sedative or addictive properties of opioids. Side effects can include dizziness, headache, and gastrointestinal disturbances.

Question 10

Expectorants

Answer 10

Guaifenesin [Mucinex, Humibid]
 Renders cough more productive by stimulating flow of
respiratory tract secretions
 Higher doses may be effective

Question 11

Mucolytics

Answer 11

 Hypertonic saline
 Acetylcysteine
-Mucolytics react directly with mucus to make it
more watery
 High sulfur content, “rotten egg” smell
 Can trigger bronchospasm

Question 12

Common Cold

Answer 12

Acute upper respiratory viral infection
 Rhinorrhea, nasal congestion, cough, sneezing,
sore throat, headache, hoarseness, malaise,
myalgia
 Fever common in kids, rare in adults
 Self-limited, usually benign
 No cure; just treatment of symptoms

Question 13

Over-the-Counter (OTC)
Cold Remedies

Answer 13

Combination cold remedies usually contain two
or more of the following:
 Nasal decongestant
 Antitussive
 Analgesic
 Antihistamine (for cholinergic actions)
 Caffeine (to offset effect of antihistamine)

Question 14

Pediatric OTC Cold Remedies

Answer 14

Use with caution in young children
 Avoid OTC cold remedies in children younger than 4 to 6 years
 Use only products labeled for pediatric use
 Consult a healthcare professional before giving these drugs to a child
 Read all product safety information before dosing
 Use the measuring device provided with the product
 Discontinue the medicine and seek professional care if the child’s condition worsens or fails to improve
 Avoid using antihistamine-containing products to sedate children