The pharmacological property of aspirin comes from its ability to inhibit the synthesis of :

Correct Answer: A

Rationale: Aspirin exerts its pharmacological effects by inhibiting the synthesis of eicosanoids. Eicosanoids are signaling molecules that play a key role in inflammation, pain, and fever. Specifically, aspirin inhibits the enzyme cyclooxygenase (COX), which is crucial for the production of prostaglandins from arachidonic acid. By blocking COX, aspirin reduces the formation of pro-inflammatory prostaglandins, ultimately leading to its anti-inflammatory, analgesic, and antipyretic effects. This mechanism also accounts for aspirin's ability to inhibit platelet aggregation, which is why it is commonly used as an antithrombotic agent.

Correct Answer: A

Rationale: For first-order kinetics, the rate of elimination is directly proportional to plasma drug concentration, ensuring constant percentage clearance over time.

Correct Answer: D

Rationale: Cough medicines, like dextromethorphan, suppress nonproductive (dry) coughs to aid rest, especially when sleep is disrupted . This targets symptomatic relief appropriately, avoiding overuse. Green secretions suggest infection, where suppressing cough could hinder clearance, requiring medical evaluation instead. Fever over 102°F indicates illness severity, not a cue for cough medicine alone. Bronchitis often involves productive cough, where suppressants are less suitable. The nurse's best response (D) aligns with cough suppressants' purpose—relieving dry, disruptive coughs—ensuring safe, targeted use for the child's comfort.

Correct Answer: B

Rationale: The highest percentage of sodium and water resorption back into the bloodstream occurs in the proximal tubule of the nephron. The proximal tubule is responsible for reabsorbing about 65-75% of the filtered sodium and water, along with various other solutes. It has a high density of microvilli, which increases its surface area for efficient reabsorption. Additionally, the proximal tubule plays a vital role in maintaining the body's fluid and electrolyte balance by reclaiming essential substances from the filtrate before it moves further along the nephron.

Correct Answer: B

Rationale: Migraine symptoms (unilateral pain, photophobia, nausea) respond to sumatriptan, a 5-HT1B/1D agonist. Option , blocking serotonin-mediated nociceptive signaling, is correct-sumatriptan constricts cranial vessels and inhibits trigeminal pain pathways. Option , COX blockade, is NSAIDs' mechanism. Option , prostaglandin synthesis, is similar. Options and (E), opioid receptor stimulation, are unrelated. Sumatriptan's serotonin action targets migraine-specific pathophysiology, relieving this patient's symptoms.

Correct Answer: A

Rationale: Varenicline, a nicotinic receptor partial agonist, aids smoking cessation. Abnormal dreams are common, reflecting CNS effects. Gastric ulcers , pancreatitis , photosensitivity , and seizures (E) are rare. Dreams align with its neuropsychiatric profile, a key counseling point.

Correct Answer: B

Rationale: Diazepam, a benzodiazepine, has active metabolites (e.g., desmethyldiazepam) with longer half-lives, contributing to its effects, so that's false. Activated charcoal is effective in overdose by adsorbing diazepam, reducing absorption, a true statement and standard intervention. It undergoes minimal, not extensive, enterohepatic recirculation, making that false. It's a GABA agonist, enhancing chloride influx via benzodiazepine receptors, not an antagonist, so that's incorrect. It also inhibits spinal reflexes, aiding muscle relaxation. The overdose utility of charcoal highlights its role in emergency management, binding unabsorbed drug in the gut, a key pharmacokinetic intervention distinct from flumazenil reversal.

Correct Answer: D

Rationale: A drug that has both affinity and intrinsic activity is known as a partial agonist. Affinity refers to the drug's ability to bind to a receptor, while intrinsic activity is the drug's ability to activate the receptor and produce a response. A partial agonist binds to the receptor with affinity but only activates the receptor to a partial extent compared to a full agonist. This results in a less potent response compared to a full agonist but also blocks the full agonist's effects, making it act as an antagonist in the presence of a full agonist. In summary, a drug that has both affinity and intrinsic activity is classified as a partial agonist because it binds to the receptor and activates it but to a lesser extent than a full agonist.

Correct Answer: C

Rationale: The statement "I'll have my physician lower my dosage once I start to feel okay" indicates an understanding of the treatment regimen because Diazepam is typically used as a short-term treatment for alcohol withdrawal symptoms. Once the client starts to feel okay, it is important to gradually taper off the medication under the guidance of a healthcare provider to prevent withdrawal symptoms. This demonstrates the client's understanding of the appropriate course of treatment and the need for medical supervision throughout the process.