Correct Answer: C

Rationale: Regular insulin typically exhibits a peak effect approximately 1 to 5 hours after administration. It is important for clients to be aware of this timing to ensure optimal management of their blood glucose levels. Insulin glargine, NPH insulin, and Insulin lispro have different onset and peak times compared to Regular insulin, making them less likely to match the desired peak effect within the specified time frame.

Correct Answer: B

Rationale: Warfarin is contraindicated for a client taking Gingko Biloba due to the potential interaction. Gingko Biloba can suppress coagulation and increase the risk of bleeding or hemorrhage when taken with anticoagulants like Warfarin.

Correct Answer: B

Rationale: Coarse tremors are a common sign of Lithium toxicity. Monitoring for tremors is crucial as they can indicate a potentially serious complication that requires immediate intervention. While other options such as severe hypertension, constipation, and muscle spasm may be symptoms of various conditions, they are not typically associated with Lithium toxicity.

Correct Answer: C

Rationale: Sucralfate can interfere with the absorption of phenytoin. To prevent this interaction, the client should allow a 2-hour interval between taking sucralfate and phenytoin. This timing helps to ensure adequate absorption and effectiveness of both medications without compromising therapeutic outcomes.

Correct Answer: C

Rationale: The correct answer is to instruct the client to avoid drinking grapefruit juice. Grapefruit juice can inhibit the metabolism of Verapamil, leading to increased blood levels of the medication, which can potentiate its effects, potentially causing adverse reactions like hypotension and bradycardia.