A nurse is reviewing the medical history of a client who has osteoarthritis. The client asks the nurse about taking the supplement chondroitin with glucosamine. The nurse should instruct the client to use this supplement with caution because of which of the following findings in the client's history?

Choice A rationale:
(Potassium level) Lovastatin is a medication used to treat high cholesterol levels. While potassium levels are important to monitor for certain conditions, they are not directly related to the initiation of lovastatin therapy. Therefore, this is not the correct choice for diagnostic testing before starting the medication.
Choice B rationale:
(Hemoglobin level) Hemoglobin levels are important to assess for anemia or other blood disorders. However, they are not specifically required before starting lovastatin therapy. Therefore, this is not the correct choice for diagnostic testing before starting the medication.
Choice C rationale:
(Kidney function tests) While kidney function tests are essential for many medications to ensure proper excretion and avoid toxicity, they are not directly related to the initiation of lovastatin therapy. Therefore, this is not the correct choice for diagnostic testing before starting the medication.
Choice D rationale:
(Liver function tests) Liver function tests are crucial before starting lovastatin therapy. Lovastatin is metabolized in the liver, and it can potentially cause liver damage or abnormalities in liver enzymes. Monitoring liver function helps detect any pre-existing liver conditions and ensures the safe use of the medication. Therefore, this is the correct choice for diagnostic testing before starting the medication.

Choice A rationale:
Is not suitable for a client who has undergone a mastectomy with axillary lymph node dissection. This exercise may put a strain on the surgical site and cause discomfort or injury.
Choice B rationale:
Is also not appropriate for a postoperative mastectomy client. It involves using the left hand extensively, which could potentially disrupt the healing process and cause pain.
Choice C rationale:
Is not recommended for a postoperative mastectomy client. It involves significant upper body movement, which may not be well-tolerated after surgery, especially with lymph node dissection.
Choice D rationale:
This exercise is suitable for a postoperative mastectomy client as it helps in maintaining hand and arm mobility without putting excessive strain on the surgical site. It also aids in preventing complications like lymphedema, which is a potential concern after lymph node dissection.