A 34-year-old woman underwent magnetic resonance imaging (MRI) to investigate an acoustic neuroma. Because the woman had had a mild allergic reaction to contrast media in the past, she was given a prescription for drugs to be taken before the MRI. Which of the following drugs should be included in that prescription?

Correct Answer: D

Rationale: The correct answer is D: Diphenhydramine. Diphenhydramine is a first-generation antihistamine that can help prevent allergic reactions to contrast media. It works by blocking the action of histamine, which is released during allergic reactions. This drug is commonly used for pre-medication to prevent allergic reactions to contrast media in patients with a history of mild reactions. Choice A (Fluorocortisone) is a corticosteroid and is not typically used for preventing allergic reactions to contrast media. Choice B (Famotidine) is a histamine-2 blocker used for stomach acid reduction and is not indicated for preventing allergic reactions. Choice C (Zafirlukast) is a leukotriene receptor antagonist used for asthma and allergies, but it is not typically used for pre-medication before MRI with contrast media.

Correct Answer: B

Rationale: The correct answer is B: Trigeminal nerve. Sumatriptan is a serotonin receptor agonist that acts on serotonin receptors in the trigeminal nerve to reduce inflammation and pain associated with migraines. The trigeminal nerve is a key player in the pathophysiology of migraines, transmitting pain signals from blood vessels and meninges to the brain. The other choices (A: Nucleus accumbens, C: Vestibular nuclei, D: Chemoreceptor trigger zone) are not directly involved in the pathophysiology of migraines or the mechanism of action of sumatriptan. The nucleus accumbens is primarily associated with reward and motivation, the vestibular nuclei are involved in balance and spatial orientation, and the chemoreceptor trigger zone is related to the regulation of vomiting.

Correct Answer: D

Rationale: Most drugs are absorbed in the GI tract via passive diffusion (Choice D), driven by lipid solubility and concentration gradients across membranes. Active transport (Choice A) requires energy, filtration (Choice B) is minor for drugs, and endocytosis/exocytosis (Choice C) is rare for small molecules.

Correct Answer: B

Rationale: Intravenous injections are not more suitable for oily solutions, making option B) FALSE the correct answer. Oily solutions can lead to complications such as embolisms and tissue damage when injected intravenously. Intravenous injections are typically reserved for aqueous solutions that can be easily and safely administered into the bloodstream without causing harm. Option A) TRUE is incorrect because intravenous injections are not recommended for oily solutions due to the associated risks. Option C) None and option D) All of the above are also incorrect as the correct answer is specifically option B. In an educational context, understanding the appropriate routes of administration for different types of medications is crucial for healthcare professionals to ensure patient safety and optimal therapeutic outcomes. It is essential to follow best practices and guidelines to minimize the risk of adverse events when administering medications to patients of all ages.

Correct Answer: B

Rationale: In pharmacology, metabolic transformation is a crucial process that drugs undergo in the body to be broken down and eliminated. Phase 1 metabolism involves reactions like oxidation, reduction, and hydrolysis, which are essential for converting drugs into more water-soluble forms for easier excretion. Therefore, option B, "Transformation of substances due to oxidation, reduction, or hydrolysis," is the correct answer. Option A, "Acetylation and methylation of substances," is incorrect because acetylation and methylation are examples of Phase 2 metabolism, not Phase 1. These reactions typically occur after Phase 1 reactions and involve conjugation of the drug with endogenous molecules to facilitate elimination. Option C, "Glucuronide formation," is also incorrect because it is a specific example of Phase 2 metabolism where drugs are conjugated with glucuronic acid to increase their water solubility. Option D, "Binding to plasma proteins," is unrelated to metabolic transformation. Drug binding to plasma proteins is important for distribution in the body but is not a part of the metabolic transformation process. Understanding the different phases of drug metabolism is essential for healthcare professionals to predict drug interactions, side effects, and dosing adjustments based on individual variations in metabolism. It is crucial for safe and effective medication management across the lifespan.