Usefulness of saliva lithium estimation.

Estimation of lithium in 24 samples of serum and saliva show that there is a very high correlation between the lithium levels in serum and saliva (r= + 0-88). The ratio found in our patients is very similar to that reported from North America. Estimation of lithium in saliva at different periods of time show there is a good degree of stability for saliva lithium levels. Thus saliva can be used as a substitute for serum for lithium monitoring. The practical advantages of this are discussed.