Clinical, Biochemical and Neurological Outcomes in Bipolar Patients with Lithium Intoxication at A Tertiary Care Hospital Sindh

Abstract

Background: Bipolar disorder (BD) affects a significant portion of the global population, with lithium being a cornerstone in its treatment. However, the therapeutic index of lithium is narrow, and its effectiveness can be overshadowed by the risk of toxicity, especially at higher serum levels. Understanding the impact of varying lithium concentrations on clinical, biochemical, and neurological outcomes is crucial in the management of BD. Objective: To assess the clinical, biochemical, and neurological changes associated with different levels of lithium toxicity in patients with bipolar disorder and to determine the safe and effective range of lithium serum levels. Methods: A prospective cross-sectional study was conducted at Jinnah Post Graduate Medical Center, Karachi, involving 100 bipolar disorder patients on lithium therapy, categorized into three groups based on their serum lithium levels: Category I (<1.2 mmol/L), Category II (1.2 – 2.5 mmol/L), and Category III (>2.5 mmol/L). Clinical assessments, laboratory investigations (including renal and thyroid function tests), and neurological evaluations were conducted. Data were analyzed using SPSS version 25, with the t-test and Chi-square test employed for quantitative and qualitative comparisons, respectively. Results: Patients with serum lithium levels above 2.5 mmol/L (Category III) demonstrated significantly higher rates of clinical toxicity, renal dysfunction, and neurological complications compared to lower lithium level groups. Renal function parameters (serum creatinine and urea) and thyroid function (TSH levels) were notably altered in Category III. The incidence of neuropsychiatric symptoms was also significantly higher in this group, with severe neurotoxic effects observed in 27% of these patients. Conclusion: The study highlights the critical importance of maintaining serum lithium levels within a therapeutic range to avoid severe adverse effects. Lithium levels above 2.5 mmol/L significantly increase the risk of renal dysfunction, thyroid abnormalities, and neurotoxicity. Regular monitoring and individualized treatment adjustments are essential for optimizing patient safety and treatment efficacy.