This document discusses lithium, a mood stabilizing drug used to treat bipolar disorder. It describes lithium's indications, pharmacokinetics, mechanisms of action, dosage, therapeutic levels, side effects, toxicity, contraindications, and the nurse's role in monitoring patients taking lithium. Key responsibilities for nurses include assessing renal and thyroid function before starting lithium, ensuring regular dosing, monitoring for side effects, maintaining fluid balance, and obtaining frequent lithium level and lab tests.