Salivary gland function in patients on chronic lithium treatment

Salivary gland function was studied in 14 manic-depressive patients treated with lithium carbonate (Li) for 4 to 120 months. Function level was evaluated by means of sialometry, dynamic salivary scintigraphy, and sialography. Daily Li dose, serum Li concentration, duration of Li therapy, and caries activity index were correlated with the salivary function parameters studied. Hyposalivation was noted in 71% of the patients, showing good correlation with the scintigraphic (r = 0.94) and sialographic (r = 0.87) results. Duration of Li therapy was poorly correlated with the degree of salivary gland dysfunction and with the caries activity index, whereas the correlation between duration of therapy and each of the three salivary function parameters was erratic. Because four of the patients exhibited normal salivation, we suggest that there are some additional factors (e.g., genetic or thyroid function level) that might be involved in salivary dysfunction connected with Li therapy.