Haemodiafiltration sustained for >16 hours allows effective removal of total body lithium, thereby avoiding rebound effects. Continuous arteriovenous haemodiafiltration and continuous venovenous haemodiafiltration increase lithium clearance, albeit to a lesser extent than haemodialysis, and are more widely accessible.

Although haemodialysis is highly effective in removing circulating lithium, serum concentrations often rebound so repeated or prolonged treatment may be required. Therefore, enhanced lithium clearance has been explored as a means of minimising exposure to high tissue concentrations. Lithium toxicity may be life threatening, or result in persistent cognitive and neurological impairment. Conversely, chronic toxicity and acute-on-therapeutic ingestion are associated with prolonged exposure to higher tissue concentrations and, therefore, greater toxicity.

Acute ingestion in lithium-naive patients is generally associated with only short-lived exposure to high concentrations, due to extensive distribution of lithium throughout the total body water compartment. Lithium has a narrow therapeutic range, and several well characterised adverse effects limit the potential usefulness of higher doses. Lithium salts have been used in the prophylaxis and treatment of depression and bipolar disorder for >50 years.

Lithium toxicity antidote