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 B
Explanation
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 areinvolved 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.
Correct Answer is B
Explanation
A) Ipratropium bromide: While ipratropium is used to manage bronchospasm, it is typically not the first choice for acute asthma attacks. It has a slower onset of action compared to short-acting beta-agonists like albuterol and is generally used as an adjunct therapy rather than for immediate relief.
B) Albuterol: This medication is a short-acting beta-agonist that provides rapid relief of bronchospasm during an acute asthma attack. It works by relaxing the muscles in the airways, making it the preferred first-line treatment for quick relief in asthma exacerbations.
C) Salmeterol: This medication is a long-acting beta-agonist (LABA) used for long-term control of asthma symptoms, not for immediate relief. It has a delayed onset of action and should not be used as a rescue medication during an acute attack, as it may take longer to provide effects.
D) Budesonide: This is an inhaled corticosteroid that helps in controlling chronic inflammation associated with asthma. While important for long-term management, it is not effective for the rapid relief of acute symptoms and should not be used during an asthma attack.