Correct Answer: B

Rationale: The correct answer is B: Problems with visual acuity. Ethambutol is known to cause optic neuritis, leading to a decrease in visual acuity and color discrimination. Therefore, any visual changes should be reported promptly to prevent further complications.

Correct Answer: C

Rationale: Older clients are particularly vulnerable to central nervous system side effects of cimetidine. The most frequent side effect is confusion. It is crucial for nurses to be vigilant in monitoring for confusion as it can impact the client's safety and well-being. While tremors, dizziness, and hallucinations are possible side effects, confusion is the most common in older clients taking cimetidine.

Correct Answer: C

Rationale: Blurred vision is an adverse effect of methocarbamol (Robaxin) and should be reported to a health care provider.

Correct Answer: B

Rationale: Lansoprazole is a gastric acid pump inhibitor commonly used to treat gastroesophageal reflux disease (GERD) by reducing stomach acid. Heartburn is a key symptom of GERD, so asking about heartburn can help assess the effectiveness of lansoprazole in managing acid reflux symptoms.

Correct Answer: B

Rationale: Nalidixic acid can intensify the effects of oral anticoagulants by displacing these agents from binding sites on plasma proteins. When an oral anticoagulant, like warfarin sodium (Coumadin), is combined with nalidixic acid, a decrease in the anticoagulant dosage may be necessary to avoid excessive anticoagulation and potential bleeding risks.