The incidence and clinical correlates of lithium toxicity: a retrospective review

Lithium is a commonly prescribed pharmacological treatment for mood disorders. It is associated with a number of side effects and potentially serious toxicity. To date, there is little data from Irish samples on the subject of Lithium toxicity. To examine the incidence and clinical correlates of lithium toxicity in Cork, Ireland. Our study identified 130 cases of biochemical lithium toxicity over 5 years, with an incidence rate of approximately 5.4 cases per 100,000 per year. Mean toxic lithium level was 2.16 mmol/L +/- SD 0.87 mmol/L. Of these, 36% cases were reviewed medically in the general hospital at the time of toxicity. A number of issues in relation to lithium toxicity were identified. Neurological symptoms were common, including tremor, confusion, ataxia, drowsiness. However, only 4.2% patients were reviewed by a neurologist while in hospital. Medications that interact with lithium were found in 50% cases, with significant polypharmacy in 15%. The psychiatric services were involved in patient care in 76% cases, and 85% patients presenting with toxicity were reviewed by a psychiatrist. Rates of admission to hospital and haemodialysis were 70 and 11%, respectively. Improvements in the standards of care in relation to lithium prescribing are required.