Matium SR 450 Tablet contains lithium carbonate 450 mg, a mood stabilizer primarily indicated for the treatment and maintenance of bipolar disorder. Lithium carbonate exerts its therapeutic effects by modulating neurotransmitter activity and stabilizing mood swings, thereby reducing the frequency and severity of manic and depressive episodes. It is effective in the prophylaxis of bipolar mania and depression, helping to prevent relapse and improve overall mood stability. The sustained-release formulation ensures a gradual release of lithium, maintaining steady plasma levels and minimizing peak-related side effects. Matium SR 450 is also utilized off-label in certain cases of treatment-resistant depression and schizoaffective disorder under medical supervision. Dosage should be individualized based on clinical response and serum lithium levels, which require regular monitoring due to lithium’s narrow therapeutic index and potential toxicity. Common adverse effects include gastrointestinal discomfort, polyuria, tremor, and weight gain, while serious toxicity may manifest as neurological impairment, renal dysfunction, or hypothyroidism. Patients should maintain adequate hydration and avoid excessive sodium intake to prevent lithium toxicity. Matium SR 450 should be used cautiously in patients with renal or cardiovascular conditions and is contraindicated during pregnancy and breastfeeding unless benefits outweigh risks. Regular clinical and laboratory evaluation is essential to ensure safe and effective therapy.