The mechanism of action of drugs is best determined by its:

Correct Answer: B

Rationale: Pharmacodynamics refers to the study of how drugs exert their effects on the body, including the interactions between a drug and its target molecule or receptor leading to a biological response. Understanding a drug's mechanism of action involves determining how it interacts with specific receptors, enzymes, ion channels, or other molecular targets within the body to produce the desired therapeutic effects. Pharmacokinetics, on the other hand, involves the study of how drugs move through the body, including their absorption, distribution, metabolism, and excretion, which although important for determining effective drug dosages and concentrations, does not directly provide insight into how a drug exerts its pharmacological effects. Therapeutic action refers to the overall clinical effect of the drug in treating a specific condition, which is influenced by its pharmacodynamics. Pharmaceutical preparations involve drug formulation and delivery methods, such as tablets, injections, or creams, which affect a drug's bioavailability but do not determine its specific mechanism of action.

Correct Answer: C

Rationale: Pain is defined as an unpleasant sensory and emotional experience associated with actual or potential tissue damage. It is a complex phenomenon involving both physical and emotional components. Pain serves as a protective mechanism, alerting the body to potential harm or injury, and prompting appropriate responses to prevent further damage. Pain can be acute or chronic, and may vary in intensity, duration, and location depending on the underlying cause. Analgesia refers to the relief of pain, inflammation is the body's response to injury or infection, and irritation typically refers to a mild reaction to something that is uncomfortable or annoying, but not necessarily indicating tissue damage.

Correct Answer: A

Rationale: Failed to generate a rationale of 500+ characters after 5 retries.

Correct Answer: B

Rationale: Drugs that block both alpha- and beta-adrenergic receptors are primarily used to treat cardiac-related conditions. Phentolamine, a nonselective alpha-adrenergic blocking agent, is used to treat extravasation of IV norepinephrine or dopamine and hypertension related to a pheochromocytoma. Alpha1-selective adrenergic blocking agents are used for treatment of hypertension and benign prostatic hyperplasia. The beta-adrenergic blocking agents are used to treat cardiovascular problems (hypertension, angina, migraine headaches) and to prevent reinfarction after myocardial infarction. Beta1-selective adrenergic blocking agents are used for treating hypertension, angina, and some cardiac arrhythmias. The nurse should understand the indications for these agents to ensure safe and effective administration.

Correct Answer: C

Rationale: Metoprolol, a beta-blocker, can cause bradycardia. The nurse must assess the patient’s heart rate before administration to ensure it is within a safe range (typically >60 beats/minute). Respirations (A), temperature (B), and oxygen saturation (D) are less critical for metoprolol administration.