The patient has been receiving amitriptyline (Elavil) for 2 weeks. He tells the nurse he doesn't think this medicine is working, as he is still depressed. What is the best response by the nurse?

Correct Answer: A

Rationale: Amitriptyline requires 2-6 weeks for full antidepressant effect, increasing neurotransmitters gradually. After 2 weeks, persistent depression is expected, so 'It can take several weeks' educates on the timeline, encouraging adherence. Choice B dismisses feelings, risking trust. Choice C assumes failure prematurely. Choice D exaggerates to months, discouraging patience. A provides accurate, supportive guidance, aligning with tricyclic pharmacology, making it the best response.

Correct Answer: A

Rationale: A blood pressure of 88/62 mm Hg indicates hypotension, which is a contraindication for nitrates and nitrites use. Nitrates and nitrites are vasodilators that can further lower blood pressure, potentially leading to severe hypotension and cardiovascular collapse in a patient with already low blood pressure. Therefore, caution should be exercised in administering nitrates and nitrites to a patient with hypotension. In this case, the presence of severe chest pain may be indicative of a myocardial infarction, which would typically warrant the consideration of nitroglycerin (a nitrate) administration for chest pain relief. However, in the presence of hypotension, alternative treatment options may need to be considered first to stabilize the blood pressure before nitrate administration.

Correct Answer: D

Rationale: Bipolar disorder features mood cycles-depression and mania (hyperactivity)-per DSM-5, distinct from unipolar depression. It's not just cyclic depression, nor ADHD-linked. Seasonal shifts are separate (SAD). Mania-depression cycles define it, clarifying diagnosis.

Correct Answer: C

Rationale: In the context of mild hyponatremia, which is a condition where there is a lower-than-normal concentration of sodium in the blood, treatment often involves administering intravenous normal saline infusion administered slowly. This helps to incrementally increase sodium levels in the blood while also ensuring proper hydration. Normal saline is preferred over other fluid solutions as it helps to maintain a stable electrolyte balance. In cases of severe hyponatremia or symptoms like seizures, more aggressive treatment may be necessary, but for mild cases like that described in the scenario, normal saline infusion is typically the appropriate choice.

Correct Answer: A

Rationale: Penicillin G is a beta-lactam antibiotic that can cause severe allergic reactions, including anaphylaxis. Having epinephrine on hand is crucial for managing such emergencies. Collecting a culture and sensitivity before the first dose ensures the infection is caused by a penicillin-susceptible organism. Mouth ulcers are not a common side effect of penicillin, but monitoring for superinfections like oral thrush is important. Limiting fluid intake to 1000 mL/day is incorrect, as adequate hydration helps maintain renal function and prevents crystalluria. No particular interventions are required is incorrect, as penicillin requires careful monitoring for efficacy and adverse effects.

Correct Answer: A

Rationale: Acetaminophen overdose initially presents asymptomatically, but its toxic metabolite, NAPQI, causes delayed harm. Option , depletion of endogenous antioxidants (glutathione), is correct-NAPQI, formed via CYP450 metabolism, overwhelms glutathione, leading to oxidative stress and hepatotoxicity. Option , hapten formation, occurs with some drugs but not acetaminophen's primary toxicity. Option , cytochrome C oxidase inhibition, is cyanide's mechanism, not acetaminophen's. Option , ischemia from reduced blood flow, isn't the issue-damage is metabolic. Option (E), gallbladder paralysis, is irrelevant. NAPQI's glutathione depletion disrupts detoxification, causing centrilobular necrosis, explaining the delayed presentation and justifying urgent treatment like N-acetylcysteine to replenish glutathione.

Correct Answer: A

Rationale: Metformin is a commonly prescribed medication for the management of type 2 diabetes. One of the primary mechanisms of action of Metformin is to decrease hepatic glucose production. It works by inhibiting gluconeogenesis, which is the process by which the liver produces glucose. By reducing glucose production in the liver, Metformin helps to lower blood sugar levels and improve insulin sensitivity. This action helps to control hyperglycemia in patients with diabetes. The other options provided do not describe the mechanism of action of Metformin, making them incorrect choices.

Correct Answer: D

Rationale: High threshold mechanoreceptors are responsible for sensing mechanical stimuli such as pressure and touch. When these receptors are activated, one of the body's reactions is to produce analgesia, which refers to the relief of pain or a decreased sensitivity to painful stimuli. This analgesic effect is a protective mechanism that helps reduce the perception of pain in response to potentially harmful mechanical stimuli. Therefore, the reaction of the body to high threshold mechanoreceptors is often associated with analgesia rather than tolerance, withdrawal reflex, inflammation, or suppuration.

Correct Answer: B

Rationale: The kidneys filter approximately 130 mL/min of protein-free plasma, which is the glomerular filtration rate in healthy adults.