Beyond serum lithium levels, what other safety parameter should be regularly monitored in patients taking lithium?

• A. Renal function and electrolytes
• B. Hepatic enzymes
• C. Thyroid hormones
• D. Blood glucose

Answer: (A)

Regular safety monitoring for lithium focuses on the kidneys. Lithium is cleared by the kidneys and long-term use can lead to renal impairment and a condition called nephrogenic diabetes insipidus. Because of this, checking renal function and electrolytes is essential to catch early changes and guide dosing. Key tests include creatinine and estimated GFR to assess kidney filtration, and electrolytes like sodium, potassium, and BUN to watch for imbalances that can affect lithium levels and patient safety. Staying hydrated and avoiding dehydration is also important because fluid/salt balance can influence lithium retention.

Hepatic enzymes and blood glucose aren’t the primary concerns with lithium, and while thyroid function is routinely monitored because hypothyroidism can occur, the most critical regular safety parameter beyond the lithium level is renal function with electrolytes monitoring.