Clinical performance characteristics of a new photometric lithium assay: a multicenter study.

Background: Therapeutic monitoring of lithium is important because of its narrow therapeutic range and therapeutic index, low protein binding and single route of elimination. We characterized a new photometric method that avoids the specialized requirements of ion-specific electrode (ISE), atomic absorption and flame emission methods.

Methods: Minimum detectable concentration (MDC), linearity and calibration drift over 65 days were determined.