Allergy Medications: Antihistamines and Corticosteroids

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Questions and Answers

Why are antihistamines frequently combined with nasal decongestants in over-the-counter allergy medications?

Antihistamines counteract the stimulant side effects of nasal decongestants.
Antihistamines directly reduce nasal congestion by shrinking swollen nasal passages, complementing the decongestant's drying effect.
Nasal decongestants enhance the absorption and effectiveness of antihistamines, leading to a quicker onset of action.
The combination provides relief from both histamine-mediated symptoms, like itching and sneezing, and congestion, offering more comprehensive symptom control. (correct)

Mometasone, an intranasal corticosteroid, alleviates allergy symptoms via which primary mechanism of action?

By stabilizing mast cells to prevent the release of inflammatory mediators.
By directly constricting blood vessels in the nasal mucosa, reducing swelling.
By reducing inflammation in the nasal passages through the suppression of inflammatory mediators. (correct)
By immediately blocking histamine receptors in the nasal passages.

What is a significant limitation to consider when recommending cromolyn for managing allergic symptoms?

It interacts negatively with most other allergy medications, reducing their effectiveness.
It has a high risk of causing severe systemic side effects such as anaphylaxis.
It is ineffective against nasal congestion and primarily targets skin rashes.
It requires frequent administration and is mainly effective for preventing symptoms rather than treating acute episodes. (correct)

Which of the following adverse effects is most associated with the use of intranasal corticosteroids like mometasone?

Nasal irritation, nosebleeds, and possible fungal infections. (C) Signup and view all the answers

A patient taking diphenhydramine complains of dry mouth and blurred vision. Which mechanism of action of diphenhydramine is most likely responsible for these effects?

Anticholinergic effects due to muscarinic receptor blockade. (C) Signup and view all the answers

A patient reports that cetirizine makes them feel less drowsy compared to diphenhydramine. What pharmacological property of cetirizine explains this difference?

Cetirizine has a higher affinity for peripheral H1 receptors and lower penetration into the central nervous system. (A) Signup and view all the answers

Which allergic symptoms are most effectively managed by cromolyn when administered via a nebulizer?

Asthma symptoms triggered by allergens, such as wheezing and shortness of breath. (B) Signup and view all the answers

A patient is prescribed both cetirizine and mometasone for allergic rhinitis. What is the rationale for using both medications?

Cetirizine treats immediate histamine-related symptoms, while mometasone addresses underlying inflammation for long-term control. (D) Signup and view all the answers

A patient taking diphenhydramine is also prescribed a medication with anticholinergic properties for another condition. What potential drug interaction should the healthcare provider closely monitor?

Increased risk of central nervous system depression and cognitive impairment. (D) Signup and view all the answers

What is the primary advantage of using an intranasal corticosteroid, such as mometasone, compared to an oral antihistamine for treating allergic rhinitis?

Intranasal corticosteroids are more effective at relieving nasal congestion than oral antihistamines. (C) Signup and view all the answers

Why is it important to counsel patients using intranasal corticosteroids about proper administration techniques?

To ensure the medication reaches the nasal mucosa and to minimize the risk of epistaxis. (B) Signup and view all the answers

How does cromolyn differ from antihistamines and intranasal corticosteroids in its mechanism of action for treating allergic rhinitis?

Cromolyn stabilizes mast cells to prevent the release of histamine and other inflammatory mediators. (D) Signup and view all the answers

A patient using diphenhydramine regularly is considering switching to cetirizine. What should the patient be advised regarding the onset and duration of action when making this switch?

Cetirizine will have a faster onset and a longer duration of action compared to diphenhydramine. (D) Signup and view all the answers

What is a key consideration when prescribing cromolyn via nebulizer for a patient with asthma and seasonal allergies?

Cromolyn is most effective when initiated several weeks before allergy season to prevent symptom onset. (D) Signup and view all the answers

A patient reports persistent nasal congestion despite using mometasone as prescribed for two weeks. What is the most appropriate recommendation?

Continue using mometasone as prescribed, as it may take several weeks to achieve maximum benefit. (D) Signup and view all the answers

Why are first-generation antihistamines like diphenhydramine more likely to cause drowsiness compared to second-generation antihistamines like cetirizine?

First-generation antihistamines readily cross the blood-brain barrier, affecting histamine receptors in the brain. (A) Signup and view all the answers

What is the primary reason for the limited effectiveness of cromolyn in treating acute, severe allergic reactions?

Cromolyn has a slow onset of action and requires pretreatment to prevent mast cell degranulation. (D) Signup and view all the answers

A patient with seasonal allergic rhinitis and concurrent hypertension seeks a recommendation for an over-the-counter nasal decongestant. What advice is most appropriate?

Recommend a topical decongestant nasal spray for no more than 3-5 days to avoid rebound congestion. (A) Signup and view all the answers

A patient is using both intranasal mometasone and cetirizine for allergic rhinitis but still experiences significant nasal congestion. What additional agent might be considered?

A short course of an oral decongestant, used judiciously. (A) Signup and view all the answers

A healthcare provider is deciding between prescribing intranasal cromolyn and intranasal corticosteroid for a child with seasonal allergic rhinitis. Which factor would most strongly favor the use of cromolyn?

The healthcare provider wants to avoid any risk of growth suppression. (B) Signup and view all the answers

Flashcards

Antihistamine MOA

Block histamine receptors, reducing allergy symptoms like sneezing and itching.

Examples of Antihistamines

Diphenhydramine and cetirizine are common antihistamines used to treat allergy symptoms.