The nurse is reviewing discharge teaching for a patient who will be taking digoxin (Lanoxin) therapy. The nurse will teach the patient to avoid which foods when taking the digoxin?

Correct Answer: D

Rationale: Step 1: Digoxin interacts with high-fiber foods like bran muffins, decreasing its absorption. Step 2: Bran muffins can reduce the effectiveness of digoxin, leading to subtherapeutic levels. Step 3: Avoiding bran muffins can help maintain optimal digoxin levels for therapeutic effect. Summary: A - Leafy greens are okay; B - Dairy products don't interact significantly; C - Grapefruit juice can interact with certain medications, but not digoxin.

Correct Answer: A

Rationale: Step-by-step rationale for why choice A is correct: Hydrophilic agents have low ability to penetrate through cell membrane lipids due to their polar nature. Lipids are hydrophobic, causing repulsion. This prevents direct diffusion of hydrophilic molecules across the lipid bilayer. This leads to the correct answer, A. Summary of why other choices are incorrect: B: Endocytosis involves engulfing particles into cells, not typical for small hydrophilic molecules. C: The blood-brain barrier is selective and restricts the passage of hydrophilic substances. D: High reabsorption in renal tubules would apply to hydrophobic agents that can pass through lipid membranes easily, not hydrophilic agents.

Correct Answer: C

Rationale: Step-by-step rationale: 1. G-proteins are signaling proteins that transmit signals from cell surface receptors to effector elements. 2. G-proteins do not directly change the activity of effector elements like cAMP and cGMP do. 3. cAMP and cGMP are second messengers that mediate intracellular signaling processes. 4. Calcium ions act as second messengers by regulating various cellular functions. Summary: Choice C (G-protein) is the correct answer as it does not belong to second messengers category and does not directly change the activity of effector elements. Choices A, B, and D are incorrect as they are all second messengers that modulate cellular responses.

Correct Answer: B

Rationale: The correct answer is B: Lidocaine. Lidocaine is a Class Ib antiarrhythmic agent that stabilizes cell membranes by blocking sodium channels, reducing excitability and conduction velocity in cardiac tissue. It is commonly used to treat ventricular arrhythmias. Cocaine (A) is a local anesthetic but not typically used as an antiarrhythmic. Bupivacaine (C) and Ropivacaine (D) are long-acting local anesthetics and are not commonly used as antiarrhythmics due to their mechanism of action.

Correct Answer: C

Rationale: Physostigmine is the correct answer for treating atropine intoxication due to its ability to cross the blood-brain barrier and inhibit acetylcholinesterase, increasing acetylcholine levels. Neostigmine (A) is primarily used for myasthenia gravis, Carbochol (B) is a non-selective cholinomimetic, and Lobeline (D) is a nicotinic receptor agonist.