Prediction of therapeutic lithium dose: comparison and improvement of current methods

The predictive value of two methods of predicting therapeutic lithium dose was evaluated in 19 patients. A single time point lithium level determination method, modified by the use of a 900-mg instead of a 600-mg test dose, was found to be a reliable and safe predictor. A mathematical model used for predictions was found to be moderately accurate but to generally predict a lower dose than was actually required.