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

Abstract

Background: 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.

Aim: To examine the incidence and clinical correlates of lithium toxicity in Cork, Ireland.

Results: 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.

Conclusion: Improvements in the standards of care in relation to lithium prescribing are required.