Regarding calcium channel blockers:

Correct Answer: C

Rationale: All calcium channel blockers (CCBs) like verapamil and nifedipine are orally active, so that's false. Half-lives vary (e.g., nifedipine ~2-5 hours, diltiazem longer), not uniformly 8-12 hours, making that false. They block L-type voltage-gated calcium channels, reducing vascular and cardiac contractility, a true statement. They relax bronchiolar smooth muscle, not unaffected, so that's false. Dihydropyridines cause reflex tachycardia, not bradycardia. The L-type blockade is their unifying mechanism, key to antihypertensive and antianginal effects.

Correct Answer: D

Rationale: Nystatin is used to treat oral thrush in infants, a fungal infection often linked to Candida albicans, which can be transmitted between mother and child during breastfeeding. The key instruction for the caregiver is that the breastfeeding mother may also need treatment to prevent reinfection, as Candida can persist on the mother's nipples. This addresses the infection's source comprehensively. Giving medication before feeding may reduce efficacy as milk washes it away too quickly. Water beforehand isn't necessary and could dilute the dose. Using a cotton swab is a technique but not the priority instruction compared to preventing recurrence. Since the correct answer includes multiple options (3, 5), and choice D aligns with the critical need to treat the mother, it's the focus here for its systemic impact on treatment success.

Correct Answer: A

Rationale: For a 79-year-old patient taking a diuretic for hypertension, the nurse should know that extra precautions are necessary for preventing orthostatic hypotension and potential falls. Orthostatic hypotension refers to a drop in blood pressure that occurs when standing up from a sitting or lying down position. This can lead to dizziness and an increased risk of falls, particularly in elderly individuals. Therefore, the teaching point about taking extra precautions when standing up is critical to emphasize for this patient to ensure their safety and well-being. Option A is the correct choice as it highlights the importance of this teaching point for the patient's care.

Correct Answer: C

Rationale: Phenolic germicidal agents are commonly used as disinfectants due to their ability to kill microorganisms. Hexachlorophene is one type of phenolic germicidal agent that has been used as a surgical scrub in the past. It has antiseptic properties and can effectively reduce the number of bacteria on the skin, making it suitable for use in sterile environments such as surgical procedures. While phenolic germicidal agents do possess antibacterial properties, they do not typically have topical anesthetic effects like some other types of disinfectants. Additionally, while phenolic agents are used in various dental procedures, they are not specifically used in root canal therapy. The examples provided in the last statement, formocresol, cresantin, and eugenol, are not phenolic germicidal agents but rather dental materials used for different purposes.

Correct Answer: C

Rationale: Anticipatory nausea and vomiting occur before chemotherapy administration and are a conditioned response to previous chemotherapy experiences. This psychological response is triggered by cues such as the sight or smell of the treatment environment. It is distinct from acute or delayed nausea and vomiting, which occur during or after chemotherapy. Anticipatory nausea and vomiting can be challenging to manage and often require behavioral interventions or anti-anxiety medications.