Correct Answer: A

Rationale: Metformin is known to have a risk of causing lactic acidosis, particularly in clients with renal impairment or predisposing conditions. Lactic acidosis is a rare but serious adverse effect of metformin use that can be life-threatening. Metoprolol, Lisinopril, and Insulin do not have a known association with lactic acidosis. Healthcare professionals should monitor clients prescribed metformin carefully, especially those with risk factors, to detect and manage lactic acidosis promptly.

Correct Answer: A

Rationale: The correct instruction is to take Efavirenz at bedtime to prevent drowsiness and manage central nervous system side effects like dizziness and vivid dreams. While it is important to take the medication at the same time daily for consistent blood levels, the emphasis should be on bedtime to minimize the impact of these side effects. Choices B and C suggesting taking the medication with milk or juice are incorrect and not relevant to optimizing Efavirenz therapy.

Correct Answer: D

Rationale: The correct instruction for a client prescribed with Cephalexin is to complete the full course of medication. This is crucial to ensure the infection is completely treated and to reduce the risk of antibiotic resistance. Choices A, B, and C are incorrect. Taking Cephalexin with an antacid is generally not recommended as it may reduce its effectiveness. While dairy products can interfere with certain antibiotics, they do not have a direct interaction with Cephalexin. Stools turning black is not an expected side effect of Cephalexin.

Correct Answer: C

Rationale: The correct statement the nurse should include when teaching a client with a new prescription for warfarin is to report any signs of bleeding to their provider. Bleeding can indicate excessive anticoagulation, a potential side effect of warfarin therapy that needs prompt medical attention. Choices A, B, and D are incorrect because while oral hygiene measures, dietary considerations, and skin care are important, they are not the priority when teaching a client about warfarin therapy. Monitoring for and reporting signs of bleeding is crucial due to the anticoagulant effects of warfarin.

Correct Answer: C

Rationale: The correct answer is C: 'Take it with food.' Trimethoprim-sulfamethoxazole can cause gastrointestinal upset, and taking it with food helps reduce the risk of stomach irritation. It should not be taken on an empty stomach. Maintaining good hydration is important to prevent kidney-related side effects, so maintaining a fluid restriction, as in choice B, is not appropriate. Additionally, stopping the medication when manifestations subside, as in choice D, is incorrect as antibiotics should be taken for the full prescribed course to ensure eradication of the infection and to prevent antibiotic resistance.