Methods Used to Decrease Lithium Absorption or Enhance Elimination

Abstract

Objective: To review current methods, well documented and investigational, being used to decrease lithium absorption or enhance lithium elimination. Methods: The basic science and clinical literature on lithium were reviewed by a comprehensive Medline search from 1984 to 1996. Additional references were identified by reviewing the reference citations from the results of the Medline search. Results. Prevention of Absorption: Whole bowel irrigation has been demonstrated to be an effective means of enhancing lithium removal from the gastrointestinal tract. Sodium polystyrene sulfonate resin administration has been shown to be effective in binding lithium elimination in animal and human models. However, the lower limits of effective sodium polystyrene sulfonate dosing and the extent of potassium lowerhg in humans are questions that need to be answered before sodium polystyrene sulfonate resin can be recommended for routine use. Enhancement of Elimination: Saline or forced diuresis is not effective in enhancing lithium elimination unless the patient is volume or sodium depleted. The use of continuous arteriovenous hemodiafiltration or low dose dopamine to enhance lithium elimination has only been documented in case reports. Intravenous aminophylline (theophylline) is not consistently effective and its risks outweigh possible benefits. The literature supports hemodialysis as a well documented and effective means of enhancing lithium elimination. Controversy exists over the appropriate indications for its initiation. Discussion: Given the wide interpatient variability in lithium pharmacokinetics, single case reports do not provide sufficient evidence of the effectiveness of a given method to enhancelithium elimination. Because of significant differences in morbidity and mortality and pharmacokinetic profiles, case Series need to clearly delimate acute, acute-on-chronic, and chronic overdose patients. Although the literature would be enhanced by the inclusion of controlled trials, they are unlikely to be conducted because of the small number of patients that present with severe lithium toxicity. Conclusion: Whole bowel irrigation is a documented means of preventing lithium absorption following an acute overdose. Hemodialysis is the most well documented means of enhanang lithium elimination. The endpoints for hemodialysis remain controversial. Endpoints that include a combination of both clinical status and serum lithium appear to be more appropriate than endpoints based solely on a lithium concentration.