A client frequently takes diphenhydramine (Benadryl) to alleviate his upper respiratory symptoms associated with allergies. Which of the following mechanism of actions applies to diphenhydramine (Benadryl)?
stimulates effects of histamine by occupying all H receptor sites.
blocks effects of histamine by competing and occupying H1 receptor sites.
blocks effects of histamine by competing and occupying H2 receptor sites.
stimulates effects of histamine by increasing amount of H2 receptor sites.
The Correct Answer is B
A. Stimulates effects of histamine by occupying all H receptor sites: This statement inaccurately describes the action of diphenhydramine. Instead of stimulating histamine effects, diphenhydramine actually blocks them, particularly at H1 receptors, which are involved in allergic responses.
B. Blocks effects of histamine by competing and occupying H1 receptor sites: This accurately describes the mechanism of action of diphenhydramine. As an antihistamine, it competes with histamine for binding to H1 receptor sites, effectively reducing symptoms of allergies, such as sneezing, itching, and nasal congestion.
C. Blocks effects of histamine by competing and occupying H2 receptor sites: This option is incorrect because H2 receptor antagonists are used primarily to reduce gastric acid secretion, not to treat allergic reactions. Diphenhydramine specifically targets H1 receptors, not H2 receptors.
D. Stimulates effects of histamine by increasing the amount of H2 receptor sites: This statement is also incorrect. Diphenhydramine does not stimulate histamine activity or increase receptor sites. Instead, it functions to inhibit the action of histamine at H1 receptors, which is fundamental in alleviating allergy symptoms.
Free Nursing Test Bank
- Free Pharmacology Quiz 1
- Free Medical-Surgical Quiz 2
- Free Fundamentals Quiz 3
- Free Maternal-Newborn Quiz 4
- Free Anatomy and Physiology Quiz 5
- Free Obstetrics and Pediatrics Quiz 6
- Free Fluid and Electrolytes Quiz 7
- Free Community Health Quiz 8
- Free Promoting Health across the Lifespan Quiz 9
- Free Multidimensional Care Quiz 10
View Related questions
Correct Answer is A
Explanation
A. Use this inhaler 15 minutes prior to physical activity: This is the correct recommendation for cromolyn. It is a mast cell stabilizer that helps prevent asthma symptoms by inhibiting the release of inflammatory mediators. Using it before physical activity can help minimize exercise-induced bronchospasm.
B. Tachycardia is an adverse effect associated with this medication: This statement is misleading. Cromolyn is not typically associated with tachycardia as an adverse effect. Unlike bronchodilators, which can cause increased heart rate, cromolyn primarily works to stabilize mast cells and has a different side effect profile.
C. This medication should not be discontinued abruptly: While it is generally good practice to consult a healthcare provider before stopping any asthma medication, cromolyn does not have a significant risk of withdrawal symptoms like corticosteroids might. It is more important to maintain regular use for effectiveness rather than fear abrupt discontinuation.
D. Injections are required weekly to properly prevent asthma attacks: This statement is incorrect. Cromolyn is administered via inhalation, not by injection, and does not require weekly injections. Patients should use the inhaler as prescribed, typically several times a day, depending on their individual treatment plan.
Correct Answer is C
Explanation
A. CNS Depressants: While there may be general concerns about using multiple medications that affect the central nervous system, CNS depressants do not have a direct interaction with oxymetazoline. Oxymetazoline is primarily a nasal decongestant and its interactions are more specific to other classes of medications.
B. Short Acting Beta Agonist: Short-acting beta agonists (SABAs) are bronchodilators used in asthma management. There is no direct interaction with oxymetazoline; they are used for different purposes and act on different receptors.
C. Monoamine oxidase inhibitors (MAOIs): This option is correct. MAOIs can potentially interact with oxymetazoline, leading to increased blood pressure and other cardiovascular effects. The combination can cause vasoconstriction due to the stimulant effects of both oxymetazoline and the increased levels of norepinephrine resulting from MAOI inhibition.
D. Mast Cell Inhibitors: Mast cell stabilizers do not interact directly with oxymetazoline. These medications are used primarily to manage allergic responses and asthma symptoms and do not have a significant effect on the actions of oxymetazoline.