Ramelteon (Rozerem) is prescribed for a patient with insomnia. The nurse checks the patient’s medical history, knowing that this medication is contraindicated in which disorder?

Correct Answer: C

Rationale: The correct answer is C: Liver disease. Ramelteon is metabolized in the liver, so patients with liver disease may have impaired drug metabolism, leading to potential toxicity. Coronary artery disease (A), renal insufficiency (B), and anemia (D) are not contraindications for ramelteon as they do not directly affect drug metabolism in the liver.

Correct Answer: B

Rationale: The correct answer is B, Grapefruit juice. Grapefruit juice can interact with antilipemic drugs by inhibiting the enzyme CYP3A4, leading to increased drug levels in the body and potential toxicity. Oatmeal (A) is a healthy food choice and does not significantly interact with antilipemic drugs. Licorice (C) can interact with medications such as corticosteroids but not specifically antilipemic drugs. Dairy products (D) can interfere with the absorption of some medications but do not have a significant interaction with antilipemic drugs.

Correct Answer: D

Rationale: The correct answer is D, folic acid. Folic acid is essential for the development of the fetal neural tube, reducing the risk of defects. Adequate levels are crucial before and during pregnancy. Vitamin B12 is important for neurological function, but not specifically for neural tube development. Vitamin D is important for calcium absorption but not directly related to neural tube defects. Iron is essential for red blood cell formation but does not specifically reduce the risk of neural tube defects.

Correct Answer: B

Rationale: The correct answer is B because "affinity" refers to how tightly a drug binds to a receptor. This is crucial for the drug to exert its pharmacological effect. A: Plasma protein binding is not specifically related to affinity but affects drug distribution. C: Inhibiting potency is different from affinity, which is about binding strength. D: Bioavailability is about drug absorption, not binding to receptors. Thus, B is the most appropriate choice.

Correct Answer: B

Rationale: The correct answer is B. Charged cationic forms of local anesthetics do not penetrate biological membranes more readily than uncharged forms. This is because charged molecules have difficulty crossing cell membranes due to their polarity. In contrast, uncharged forms easily pass through lipid membranes. Therefore, statement B is incorrect. Statements A, C, and D are correct. A is true because local anesthetics can exist in both uncharged and cationic forms in tissues. C is true because local anesthetics are less effective in inflamed tissues due to increased acidity and altered tissue permeability. D is true because low pH in inflamed tissues inhibits the dissociation of nonionized molecules, reducing the effectiveness of local anesthetics.