Lithium (Lithobid, Eskalith)

Class

Mood stabilizer

Mechanism

Modulates neurotransmitter signaling and intracellular second messenger pathways, including inhibition of inositol monophosphatase and glycogen synthase kinase-3, stabilizing mood and reducing mania and depression

FDA-Approved Use

Bipolar disorder (acute mania and maintenance)

Off-Label Use

Postpartum psychosis, cluster headache prophylaxis, augmentation in treatment-resistant major depressive disorder (MDD)

Formulation

Oral immediate-release and extended-release tablets/capsules

Titration

300 mg p.o. 1–2 times daily, titrated based on serum lithium levels and clinical response

Dose Range

Serum levels 0.6–1.2 mEq/L (individualized)

Kinetics

Renally excreted unchanged; half-life ~24 hours; steady state reached in 5 days

Common AEs

Tremor, polyuria, polydipsia, nausea, weight gain, cognitive dulling, acne

Serious/Rare AEs

Nephrotoxicity, hypothyroidism, lithium toxicity, arrhythmias

Monitoring

Monitor serum lithium levels, renal function (creatinine), thyroid function (TSH), and electrolytes every 3–6 months or more frequently with dose changes or clinical status changes

Black Box Warning

Narrow therapeutic index; risk of toxicity and overdose

Considerations

Lithium should be used cautiously in patients at risk for dehydration or with renal impairment due to potential nephrotoxicity. Regular kidney function monitoring is essential. Long-term use may impact thyroid function, necessitating routine screening. Lithium may help reduce agitation in dementia and impulsivity in traumatic brain injury (TBI), but risks such as falls and toxicity require close monitoring.