Correct Answer: D

Rationale: Metformin's primary pharmacological action is to decrease hepatic glucose production. By reducing hepatic glucose production, metformin helps to lower blood sugar levels and improve insulin sensitivity in the liver.

Correct Answer: B

Rationale: Bruising is an adverse effect to be monitored when a client is prescribed Aspirin for myocardial infarction prevention due to its association with increased bleeding risk. Aspirin's antiplatelet effect can lead to bruising and other signs of bleeding, necessitating close observation to prevent complications.

Correct Answer: C

Rationale: Lithium is typically administered orally to ensure proper absorption and distribution in the body. It is important to follow the prescribed route of administration to achieve the desired therapeutic effect and avoid potential adverse effects.

Correct Answer: B

Rationale: When a client is receiving Gentamicin, the nurse should monitor serum creatinine levels to assess for nephrotoxicity. Gentamicin is known to potentially cause nephrotoxicity, leading to impaired kidney function. Monitoring serum creatinine levels helps in early detection of any kidney damage or dysfunction.

Correct Answer: C

Rationale: It is essential to instruct the client to apply the Nitroglycerin patch to a different site each time to prevent skin irritation and ensure consistent absorption of the medication. Rotating application sites helps maintain the effectiveness of the treatment and reduces the risk of skin reactions.