A client who suffers from severe persistent allergic asthma is prescribed omalizumab (Xolair). Which statement below correctly describes the mechanism of action associated with omalizumab (Xolair)?
Inhibits the production of leukotrienes and histamine, preventing further asthma attacks.
Inhibits mast cells from releasing histamine, preventing further asthma attacks
Selectively binds to IgE, reducing allergic mediators and asthma attacks.
Stimulates alpha-adrenergic receptors to assist in reduction of allergic related symptoms.
The Correct Answer is C
A. Inhibits the production of leukotrienes and histamine, preventing further asthma attacks: This statement is misleading. Omalizumab does not directly inhibit the production of leukotrienes or histamine; rather, it works by targeting IgE, which is involved in the allergic response.
B. Inhibits mast cells from releasing histamine, preventing further asthma attacks: While omalizumab does reduce the overall allergic response, it does so by binding to IgE rather than directly inhibiting mast cell activity. Therefore, this description does not accurately represent its primary mechanism of action.
C. Selectively binds to IgE, reducing allergic mediators and asthma attacks: This statement correctly describes the mechanism of action of omalizumab. By binding to immunoglobulin E (IgE), omalizumab prevents IgE from attaching to mast cells and basophils, thus reducing the release of allergic mediators that contribute to asthma attacks.
D. Stimulates alpha-adrenergic receptors to assist in reduction of allergic-related symptoms: This statement is incorrect. Omalizumab does not stimulate alpha-adrenergic receptors; such action is associated with certain bronchodilators. Omalizumab specifically targets IgE to mitigate allergic responses.
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View Related questions
Correct Answer is A
Explanation
A) Cetirizine (Zyrtec): This medication is classified as a second-generation antihistamine. Second-generation antihistamines are designed to be less sedating than first-generation agents, as they are less likely to cross the blood-brain barrier. Cetirizine effectively alleviates symptoms of allergic rhinitis by blocking histamine receptors and is commonly used due to its efficacy and reduced sedation compared to older antihistamines.
B) Chlorpheniramine (Aller-Chlor): Chlorpheniramine is a first-generation antihistamine. It tends to cause more sedation and has a higher likelihood of causing side effects such as drowsiness, dry mouth, and dizziness. First-generation antihistamines are typically less selective and can affect the central nervous system more significantly than their second-generation counterparts.
C) Diphenhydramine (Benadryl): This medication is also a first-generation antihistamine. It is well-known for its sedative effects and is often used for allergic reactions, as well as for its sleep-inducing properties. Like other first-generation antihistamines, diphenhydramine can cause significant drowsiness and other anticholinergic effects.
D) Montelukast (Singulair): Montelukast is not an antihistamine but rather a leukotriene receptor antagonist. It is used for the management of allergic rhinitis and asthma but works through a different mechanism by blocking leukotriene receptors, thereby reducing inflammation and mucus production. It is not classified as an antihistamine, either first or second generation.
Correct Answer is B
Explanation
A. Hypertension: Fluticasone, a corticosteroid, is not typically associated with causing hypertension directly. However, chronic use can lead to fluid retention and hypertension in some individuals, but it is not a primary concern compared to other side effects.
B. Fungal infections: This is a significant adverse effect associated with inhaled corticosteroids like fluticasone. Prolonged use can increase the risk of oral thrush and other fungal infections due to the immunosuppressive effects of corticosteroids. Monitoring for signs of infection is crucial.
C. Decreased immunity: While long-term use of systemic corticosteroids can lead to decreased immune function, inhaled fluticasone is less likely to cause significant immunosuppression. However, it can still impact local immunity in the airways, making monitoring for infections more relevant than generalized immune suppression.
D. Hypoglycemia: Fluticasone is not known to cause hypoglycemia. In fact, corticosteroids typically can lead to increased blood glucose levels rather than lowering them, especially with chronic use, making this option inaccurate in the context of monitoring for adverse effects.