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) Liver injury: Zafirlukast (Accolate) has been associated with the risk of liver injury. It is important for clients to be informed about this potential adverse effect, as it may require monitoring of liver function tests during treatment. Symptoms of liver injury, such as jaundice, dark urine, or severe fatigue, should prompt clients to seek medical attention.
B) Bradycardia: Bradycardia is not a commonly associated adverse effect of zafirlukast. This medication primarily works as a leukotriene receptor antagonist and does not typically affect heart rate significantly. Clients should be aware of other more relevant side effects rather than bradycardia.
C) Renal failure: Renal failure is not a known adverse effect of zafirlukast. While kidney function should always be monitored in patients taking various medications, zafirlukast specifically does not have a direct association with renal failure.
D) Bronchoconstriction: While bronchoconstriction is a concern in asthma management, zafirlukast is designed to prevent bronchoconstriction by blocking leukotriene receptors. Therefore, it is not an adverse effect of the medication. In fact, its purpose is to help reduce the incidence of bronchoconstriction and improve asthma control.
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.