What should healthcare providers monitor in patients taking lithium?

Monitoring serum lithium levels and renal function is crucial for patients taking lithium due to the drug's narrow therapeutic window and potential renal implications. Lithium is used primarily in the treatment of bipolar disorder and requires careful management to avoid toxicity, which can occur if lithium levels rise too high.

Renal function is monitored because lithium is primarily excreted by the kidneys. Impaired renal function can lead to elevated lithium levels, increasing the risk of side effects and toxicity. Regular blood tests to assess serum lithium concentrations ensure that the levels remain within a therapeutic range, providing efficacy while minimizing the risk of adverse effects related to lithium toxicity.

Although thyroid function is also important to monitor (since lithium can induce hypothyroidism), it is secondary to the necessity of monitoring renal function due to the direct impact of the kidneys on lithium excretion. This makes monitoring serum lithium levels and renal function the prioritized approach for patient safety.