A client who has bipolar disorder and is admitted with severe depression and suicidal ideation receives a prescription for lithium carbonate. Which instruction should the nurse provide to the client?

NSAIDs can reduce the renal clearance of lithium, leading to a dangerous increase in lithium levels and potential toxicity. This is a critical and common drug interaction that the client must understand for safe medication management. Avoiding iodine (A) is not a standard precaution for lithium therapy. Monitoring blood glucose (B) is not directly related to lithium's mechanism or side effects. While good practice, notifying a provider before dental procedures (C) is not a specific requirement for lithium use.