Dosage Forms. Capsule: 150 mg, 300 mg, 600 mg; Tablet: 300 mg; Tablet, Extended Release: 300 mg, 450 mg; Solution: 300 mg/5 mL
Common FDA Label Indication, Dosing, and Titration.
1. Bipolar disorder, maintenance therapy: Adults and Children >12 y (extended release): 900-1200 mg/d po in 2-3 divided doses; (immediate release): 300 mg po tid-qid
2. Bipolar disorder, manic episode: Adults and Children >12 y (extended release): 1800 mg/d po in 2-3 divided doses; (immediate release): 600 mg po tid
Off-Label Uses. None
MOA. Lithium’s mechanism of antimanic effect is unknown; it alters the actions of several second-messenger systems (eg, adenylate cyclase and phosphoinositol).
Drug Characteristics: Lithium
Medication Safety Issues: Lithium
Drug Interactions: Lithium
Adverse Reactions: Lithium
Efficacy Monitoring Parameters. Reduction in manic symptoms, prevention of manic and depressive episodes. Drug levels: between 1 and 1.5 mEq/L for acute mania and 0.6 and 1.2 mEq/L for long-term control; serum concentrations should not exceed 2.0 mEq/L during acute therapy. Drug levels should be drawn prior to the next dose.
Toxicity Monitoring Parameters. Kidney and thyroid function, hydration status, sodium levels. Periodic EEG and ECG exams if medically warranted.
Key Patient Counseling Points. Swallow extended-release tablets whole; do not crush or chew. Avoid activities requiring mental alertness or coordination until drug effects are realized. Report signs/symptoms of toxicity, which may vary depending on the degree of toxicity. These may include diarrhea, vomiting, tremor, ataxia, drowsiness, muscle weakness, lack of coordination, giddiness, blurred vision, tinnitus, or large volumes of dilute urine. Maintain adequate fluid intake and normal salt intake.
Clinical Pearls. Safety and effectiveness in patients <12 y of age have not been established. Lithium toxicity is closely related to serum lithium levels and can occur at doses close to therapeutic levels. Ability to tolerate lithium is greater during the acute manic phase and decreases when manic symptoms subside. Do not confuse dosing in mEq versus mg. Doses should be in mg (300 mg = 8 mEq).