The nurse is planning care for a client with major depression who is receiving a new prescription for duloxetine. Which information is most important for the nurse to obtain?

The correct answer is b. Liver function laboratory results. Choice A reason: Weight change in the last month can be an important factor to consider for a patient's overall health and may be relevant in the context of depression, as significant weight changes can be a symptom of this condition. However, it is not the most critical piece of information before prescribing duloxetine. Duloxetine is not primarily metabolized by the kidneys, and while weight can affect dosing and efficacy, it is not the most crucial factor to consider before starting treatment. Choice B reason: Liver function laboratory results are crucial to obtain before prescribing duloxetine because duloxetine is extensively metabolized by the liver. The prescribing information for duloxetine warns of the potential for hepatotoxicity, and hepatic failure has been reported in some cases. Therefore, it is essential to ensure that the patient's liver function is normal before initiating therapy with duloxetine, as impaired liver function could lead to increased levels of the medication in the body and a higher risk of side effects. Choice C reason: Recent use of other antidepressants is important to consider avoiding drug interactions, particularly with monoamine oxidase inhibitors (MAOIs), which can lead to serious, life-threatening side effects if taken together with duloxetine. While this information is important, it is not as critical as liver function, because the primary concern with other antidepressants is the timing of medication changes rather than an absolute contraindication. Choice D reason: A family history of mental illness can provide valuable information for understanding a patient's background and potential genetic predispositions to certain conditions. However, this information does not directly impact the safety and initial prescribing of duloxetine. It may be more relevant for long-term treatment considerations and prognosis rather than immediate prescription safety.