A 6-year-old boy has been started on an extended-release form of methylphenidate hydrochloride (Ritalin) for the treatment of attention deficit hyperactivity disorder (ADHD). During a follow-up visit, his mother tells the nurse that she has been giving the medication at bedtime so that it will be 'in his system' when he goes to school the next morning. What is the nurse’s appropriate evaluation of the mother’s actions?

Correct Answer: D

Rationale: The correct answer is D) The medication should be given 4 to 6 hours before bedtime to diminish insomnia. Methylphenidate hydrochloride (Ritalin) is a CNS stimulant that can cause insomnia as a side effect. By giving the medication at bedtime, the child may experience difficulty falling asleep or disrupted sleep patterns. Administering the medication earlier in the day allows for its effects to wear off by bedtime, reducing the risk of insomnia. Option A is incorrect because giving the medication at bedtime is not appropriate due to the risk of insomnia. Option B is incorrect as medication timing should be based on pharmacokinetics and individual patient needs, not on location. Option C is incorrect as methylphenidate can be taken with or without food, and meal timing does not significantly impact its absorption. In an educational context, it is crucial for healthcare providers to understand the pharmacokinetics and side effects of medications to ensure safe and effective treatment. Educating parents and caregivers on proper medication administration can improve treatment outcomes and minimize potential risks for pediatric patients with ADHD.

Correct Answer: A

Rationale: There is an increased risk for digitalis toxicity in the presence of hypokalemia, which may develop with hydrochlorothiazide therapy. Potassium supplements are often prescribed with hydrochlorothiazide therapy to prevent hypokalemia. The other options do not have interactions with hydrochlorothiazide.

Correct Answer: B

Rationale: In the context of pharmacology, pharmacokinetics refers to the study of how the body processes a drug. The correct answer, B) The study of absorption, distribution, metabolism, and excretion of drugs, is right because it specifically focuses on the key processes involved in drug disposition within the body. Option A) The study of biological and therapeutic effects of drugs, is incorrect because it pertains more to pharmacodynamics, which involves understanding how drugs interact with the body to produce their effects. Option C) The study of mechanisms of drug action, is incorrect as it also falls under pharmacodynamics, dealing with how drugs exert their effects at a cellular or molecular level. Option D) The study of methods of new drug development, is incorrect as it refers to pharmacology research related to discovering and developing new drugs rather than specifically focusing on how drugs are processed within the body. Understanding pharmacokinetics is crucial for nurses as it helps in determining the appropriate dosing regimens, anticipating potential drug interactions, and assessing the impact of patient-specific factors on drug effectiveness and safety. It forms the basis for individualizing drug therapy to optimize patient outcomes.

Correct Answer: C

Rationale: In pharmacology, understanding the concept of a substance binding to different receptor subtypes is crucial for effective medication management. The correct answer to the question is C) Agonist-antagonist. This term describes a substance that can act as an agonist at one type of receptor while simultaneously acting as an antagonist at another type of receptor. This dual action is particularly relevant in the context of drugs that have mixed effects on different receptor subtypes. Competitive antagonist (A) refers to a substance that competes with an agonist for binding to a receptor, thereby blocking the agonist's effects. Irreversible antagonist (B) irreversibly binds to a receptor, rendering it unavailable for agonist binding. Partial agonist (D) is a substance that activates a receptor but produces a submaximal response compared to a full agonist. In a clinical setting, understanding the concept of a substance binding to different receptor subtypes can guide healthcare providers in predicting the effects of a drug and managing potential interactions. This knowledge is particularly relevant when selecting medications for patients with complex conditions that may benefit from drugs with dual agonist-antagonist actions.

Correct Answer: D

Rationale: In pharmacology, the lipophilicity of a drug refers to its ability to dissolve in lipids or fats. Lipophilic drugs tend to have a higher affinity for fatty tissues and cell membranes. In the case of cardiovascular drugs, lipophilic drugs have several important characteristics: A) Lipophilic drugs are often more potent because they can easily cross cell membranes to reach their target sites within the body, leading to a higher concentration at the site of action. B) Lipophilic drugs tend to have a longer duration of action because they are metabolized more slowly and can be stored in fatty tissues for a longer period of time. C) Lipophilic drugs also have a tendency to bind more extensively to proteins in the bloodstream, which can affect their distribution, metabolism, and excretion. Therefore, the correct answer is D) All of the above, as lipophilic drugs generally exhibit these characteristics. Options A, B, and C are incorrect because they do not fully capture the comprehensive impact of lipophilicity on drug potency, duration of action, and protein binding in the context of cardiovascular pharmacology. Understanding the lipophilicity of drugs is crucial for nurses to ensure safe and effective administration, monitoring, and patient education regarding cardiovascular medications.