Monitoring lithium dose levels: estimation of lithium in blood and other body fluids.

The theoretical basis and practical application of the analytical procedures used to quantitate lithium in biological fluids, i.e., flame emission and atomic absorption, are described in their most simple form in nontechnical language. The clinical relevance of the erythrocyte to plasma ratio, saliva, urine, and spinal fluid lithium measures is discussed. Other topics include acute treatment plasma lithium levels and maintenance treatment plasma levels, pitfalls in sample collection, availability of micro (finger prick) procedures, and laboratory accuracy and evaluation.