Lithomed SR Tablet contains lithium carbonate 400 mg, a mood stabilizer primarily indicated for the treatment and maintenance of bipolar disorder, including manic and depressive episodes. Lithium carbonate exerts its therapeutic effects by modulating neurotransmitter activity and stabilizing mood swings, thereby reducing the frequency and severity of manic episodes and preventing relapse. This sustained-release formulation ensures a gradual release of lithium, maintaining steady plasma concentrations and minimizing peak-related side effects. Lithomed SR is also employed as an adjunct in managing major depressive disorder resistant to standard antidepressant therapy. The drug requires careful monitoring of serum lithium levels due to its narrow therapeutic index, with regular assessment of renal and thyroid function to detect potential adverse effects such as nephrotoxicity and hypothyroidism. Common side effects include tremors, polyuria, mild gastrointestinal discomfort, and weight gain. Patients should be advised to maintain adequate hydration and avoid sudden changes in sodium intake, as these can influence lithium levels. Contraindications include severe renal impairment, hypersensitivity to lithium, and concurrent use of certain diuretics or NSAIDs that may increase lithium toxicity. Lithomed SR Tablet should be prescribed and monitored by healthcare professionals experienced in managing mood disorders to ensure safety and efficacy.