A client with allergies has been prescribed an antihistamine.
Which response by the client demonstrates understanding of the action of antihistamine drugs?

Choice A rationale

Emphysema causes the destruction of alveolar walls and a loss of lung elasticity, leading to chronic air trapping and significantly increased work of breathing. This constant effort to breathe consumes a large amount of energy, making patients extremely susceptible to profound fatigue. Planning nursing care to include frequent rest periods between activities is the most appropriate intervention to prevent exhaustion and help the patient manage their limited physiological reserves while performing necessary daily tasks.

Choice B rationale

Incentive spirometry is primarily used to prevent atelectasis and promote lung expansion in postoperative patients or those with restricted mobility. In patients with advanced emphysema, the lungs are already hyperinflated due to the loss of elastic recoil, meaning the problem is getting air out rather than getting it in. While deep breathing is helpful, hourly incentive spirometry is not the priority intervention for emphysema and does not address the patient's primary complaints of dyspnea and fatigue.

Choice C rationale

Cool mist humidification can help loosen thick secretions in some respiratory conditions, but it is not a primary intervention for the dyspnea and fatigue associated with emphysema. In fact, for some patients with hyperreactive airways, cool mist can occasionally trigger bronchospasm, potentially worsening their shortness of breath. The focus for emphysema care should remain on energy conservation, proper breathing techniques like pursed-lip breathing, and maintaining adequate oxygenation rather than just humidifying the air.

Choice D rationale

Vigorous independent exercises are contraindicated for a patient with advanced emphysema who is already experiencing dyspnea and fatigue at rest or with minimal exertion. Excessive physical activity can lead to acute respiratory failure by overwhelming the patient's severely compromised pulmonary system and limited oxygen supply. Instead, exercise should be carefully titrated and supervised within a pulmonary rehabilitation program to improve endurance without causing dangerous levels of respiratory distress or physical exhaustion. .

Choice A rationale

Alcohol is a central nervous system depressant that can significantly potentiate the sedative effects of antihistamines, particularly first-generation ones like diphenhydramine. Combining these substances increases the risk of severe respiratory depression, impaired coordination, and extreme lethargy. For older adults, this combination is particularly dangerous as it markedly increases the risk of falls, confusion, and accidents. Therefore, avoiding alcohol is a critical safety instruction to prevent synergistic CNS depression and ensure the patient's well-being.

Choice B rationale

Antihistamines work by blocking H1 receptors, and many older formulations easily cross the blood-brain barrier, leading to significant drowsiness and sedation. Older adults are more sensitive to these side effects due to age-related changes in metabolism and distribution. Drowsiness can impair the ability to perform daily tasks and increases the risk of injury. Educating the client about this common side effect allows them to plan their activities safely and avoid driving or operating machinery while impaired.

Choice C rationale

Antihistamines should generally not be taken around the clock unless specifically directed for a chronic condition, and even then, they are often taken as needed or at specific intervals like bedtime. For many older adults, taking these medications continuously can lead to an accumulation of anticholinergic side effects, such as urinary retention, constipation, and cognitive impairment. Taking them only when allergy symptoms are present or as a single daily dose helps minimize the total drug burden and potential adverse reactions.

Choice D rationale

Antihistamines often have anticholinergic properties that lead to drying of the mucous membranes, resulting in symptoms like dry mouth, dry eyes, and thickened bronchial secretions. Increasing fluid intake helps to alleviate these drying effects and maintain hydration. For older adults, maintaining adequate hydration is also important for renal clearance of the medication. Encouraging the client to drink more water helps mitigate the uncomfortable "drying out" sensation and supports overall physiological balance during drug therapy. .