A 26-year-old woman with bipolar disorder explains to the PMHNP that she stopped taking her medication during a manic episode, but she now wants to start again. Prior to re-initiating lithium (Eskalith) for mood stabilization, which of the following labs are appropriate to obtain for this patient?

Choice A reason: While liver function tests are sometimes monitored, lithium is primarily excreted renally, making creatinine more critical than liver function tests for baseline evaluation. Choice B reason: Liver function tests alone are insufficient; kidney function must be assessed because lithium can cause nephrotoxicity. Choice C reason: A complete blood count is not required prior to initiating lithium; the focus is on renal and thyroid function and pregnancy status. Choice D reason: Baseline thyroid function is essential because lithium can affect thyroid activity. Creatinine assesses renal function since lithium is renally excreted. A pregnancy test is important due to potential teratogenic effects during pregnancy.