When administering a standard or median effective dose to a patient, the nurse explains that this amount of drug will have which effect?

Correct Answer: C

Rationale: Median effective dose (ED50) affects 50% of a population, a statistical pharmacodynamic measure, not individual guarantee. No adverse effects isn't assured-safety varies. Metabolism timing depends on half-life, not ED50. Majority effectiveness exceeds 50%. Half the population defines ED50, explaining its intent.

Correct Answer: A

Rationale: The extraction ratio (ER = hepatic clearance / liver blood flow) quantifies first-pass metabolism's impact on bioavailability (F = 1 - ER), a true statement. It doesn't directly affect volume of distribution, which is a distribution parameter, so that's false. Oral morphine's bioavailability is ~20-30%, not exactly 15%, but close, though false per key. Phenytoin's extraction ratio is low, not high, due to capacity-limited metabolism. Lidocaine's high first-pass effect prevents oral efficacy, true. The ER formula is foundational in pharmacokinetics, predicting oral drug availability.

Correct Answer: B

Rationale: Prenatal vitamins likely caused iron overdose (bloody emesis). Deferoxamine chelates iron, preventing toxicity. Aminocaproic acid treats bleeding. Dimercaprol and Penicillamine target other metals. Succimer (E) is for lead. Deferoxamine is urgent for this child.

Correct Answer: D

Rationale: Phenazopyridine is a urinary analgesic commonly used to relieve the burning sensation and pain experienced during urination, typically caused by urinary tract infection or irritation. It works by acting as a local anesthetic on the lining of the urinary tract, providing relief from discomfort. Tolterodine and oxybutynin are used to treat overactive bladder by reducing bladder spasms and urge incontinence, whereas bethanechol is a direct-acting cholinergic agonist primarily used to stimulate bladder contractions in individuals with urinary retention. Thus, for the symptom of burning sensation and pain when urinating, phenazopyridine would be the most likely urinary analgesic to be ordered.

Correct Answer: C

Rationale: Dexamethasone (Decadron) is a corticosteroid used to reduce inflammation and edema in brain tumors. A client no longer recognizing family members indicates a potential worsening of neurological status, such as increased intracranial pressure or tumor progression, which is a critical concern. Elevated blood glucose and weight gain are common side effects of steroids but are less urgent. Persistent headaches are expected but less concerning than cognitive changes. Therefore, cognitive decline is the most alarming assessment.