Correct Answer: B

Rationale: The correct answer is B: A prototype drug is a medication that is considered the standard or model for a particular drug class or category. This is because a prototype drug is typically the first drug of its kind developed within a specific drug class or category. It serves as a reference point for other drugs in the same category, providing a standard for comparison in terms of efficacy, safety, and dosing.

Explanation of other choices:
A: Incorrect. A prototype drug is not used as a placebo in clinical trials; placebos are inert substances used as controls.
C: Incorrect. A prototype drug is not necessarily only available in generic form; it can be available in both brand-name and generic versions.
D: Incorrect. A prototype drug is not exclusively prescribed for pediatric patients; it can be used across different age groups depending on the specific drug and indication.

Correct Answer: C

Rationale: The correct answer is C: Ototoxicity. Aminoglycosides are known to cause damage to the inner ear and auditory nerve, leading to hearing loss and balance issues. This is a severe adverse reaction because it can be irreversible and significantly impact a patient's quality of life. Rash (
A), nausea and vomiting (
B), and headache (
D) are common side effects of aminoglycosides but are not considered severe adverse reactions. Ototoxicity should be closely monitored during aminoglycoside therapy to prevent permanent damage.

Correct Answer: D

Rationale: The correct answer is D. Pharmacokinetics is the study of how drugs are absorbed, distributed, metabolized, and excreted by the body. This involves understanding how the body processes a drug after administration. Absorption refers to how the drug enters the bloodstream, distribution is how the drug is transported to different parts of the body, metabolism involves the breakdown of the drug in the body, and excretion is the removal of the drug or its metabolites from the body.

Choices A, B, and C do not encompass the comprehensive scope of pharmacokinetics.
Choice A focuses on drug interactions,
Choice B on drug development and manufacturing, and
Choice C on drug prescription and administration, which are not the core components of pharmacokinetics.

Correct Answer: D

Rationale: Aminoglycosides target ribosomes in bacteria, disrupting protein synthesis. They are effective against Gram-negative bacteria due to their structure and ability to penetrate the bacterial cell wall. They are not effective against viral, fungal, or Gram-positive bacterial infections as they do not have the same target or mechanism of action.

Correct Answer: C

Rationale: Selective toxicity in anti-infectives refers to the ability to target and eliminate harmful microorganisms without causing harm to the host.
Choice C is correct as it captures this essence.
Choice A is incorrect as complete elimination of all microorganisms is not selective.
Choice B is incorrect as it focuses on the host rather than the microorganisms.
Choice D is incorrect as it does not address the aspect of harm to the host.