Saliva and serum lithium monitoring in hospitalized children

Serum and saliva lithium levels are presented for 30 inpatients, ages 5.12 to 11.95 years, diagnosed as having conduct disorder of the undersocialized aggressive type. Maintenance doses of lithium carbonate ranged from 600 mg to 1,500 mg/day. Serum and saliva lithium levels were significantly correlated at optimal dose (r = .78, p less than .001) and overall (r = .83, p less than .001), lending support to the use of saliva lithium levels as an adjunct to serum lithium determinations. However, because saliva/serum lithium ratios reveal wide ranges between subjects, the use of saliva levels is limited, and laboratory assessments should be combined with careful clinical monitoring.